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  • 101. Dapporto, Leonardo
    et al.
    Bruschini, Claudia
    Dinca, Vlad
    Stockholm University, Faculty of Science, Department of Zoology.
    Vila, Roger
    Dennis, Roger L. H.
    Identifying zones of phenetic compression in West Mediterranean butterflies (Satyrinae): refugia, invasion and hybridization2012In: Diversity & distributions: A journal of biological invasions and biodiversity, ISSN 1366-9516, E-ISSN 1472-4642, Vol. 18, no 11, p. 1066-1076Article in journal (Refereed)
    Abstract [en]

    Aim Distinct insular populations are generally considered important units for conservation. In islandmainland situations, unidirectional introgressive gene flow from the most abundant, typically continental, populations into the smaller island populations can erase native insular genetic units. As an indication of threat, the concept of phenetic slope is developed, a measure proportional to differentiation and to geographical proximity. Location The Western Mediterranean, including the following islands: Sardinia, Sicily, Corsica, Balearics, circum-Italian, circum-Sicilian and circum-Sardo-Corsican archipelagos. Eastern Europe is included for comparison. Methods Geometric morphometrics was applied to 2392 male genitalia of seven butterfly species groups. Geographic Information System techniques were used to depict the pattern in the distribution of morphotypes. The slope of variation in genital shape was computed to highlight geographical areas showing abrupt morphological changes. Correlation analyses were performed between the mean slope values across sea straits separating islands and nearest sources and ecological traits of the species that underlie their colonization and migration capacity. Results Phenetic slope analysis has revealed that the strait of Messina and the northern Tyrrhenian Sea support particularly contrasting populations. In these areas, mean slopes for species also correlated with certain ecological traits of the species. Sardinia emerges as the most stable refugium for ancestral mediterranean populations. Main conclusions There is strong support for the hypothesis that Italy has experienced invasion by populations from Eastern Europe with postglacial expansion of these populations across Italy. However, propagules are impeded from invading islands by the expanse of sea straits. Even so, sea straits are not invariably barriers. Our results suggest that wind direction in combination with habitat occupancy may have maintained ancestral insular populations in key locations distinguished by phenetic compression. We conclude that native insular populations acting as barriers to introgression in the areas showing particularly steep phenetic slopes deserve attention in conservation programmes.

  • 102. Dapporto, Leonardo
    et al.
    Fattorini, Simone
    Voda, Raluca
    Dinca, Vlad
    Stockholm University, Faculty of Science, Department of Zoology. University of Guelph, Canada.
    Vila, Roger
    Biogeography of western Mediterranean butterflies: combining turnover and nestedness components of faunal dissimilarity2014In: Journal of Biogeography, ISSN 0305-0270, E-ISSN 1365-2699, Vol. 41, no 9, p. 1639-1650Article in journal (Refereed)
    Abstract [en]

    Aim Unpartitioned dissimilarity indices such as the Sorensen index (beta(sor)) tend to categorize areas according to species number. The use of turnover indices, such as the Simpson index (beta(simp)), may lead to the loss of important information represented by the nestedness component (beta(nest)). Recent studies have suggested the importance of integrating nestedness and turnover information. We evaluated this proposition by comparing biogeographical patterns obtained by unpartitioned (beta(sor)) and partitioned indices (beta(simp) and beta(nest)) on presence data of western Mediterranean butterflies. Location Western Mediterranean. Methods We assessed the regionalization of 81 mainland and island faunas according to partitioned and unpartitioned dissimilarity by using cluster analyses with the unweighted pair-group method using arithmetic averages (UPGMA) combined with non-metric multidimensional scaling (NMDS). We also carried out dissimilarity interpolation for beta(sor), beta(simp), beta(nest) and the beta(nest)/beta(sor) ratio, to identify geographical patterns of variation in faunal dissimilarity. Results When the unpartitioned bsor index was used, the clustering of sites allowed a clear distinction between insular and mainland species assemblages. Most islands were grouped together, irrespective of their mainland source, because of the dominant effect of their shared low richness. bsimp was the most effective index for clustering islands with their respective mainland source. bsimp clustered mainland sites into broader regions than clusters obtained using bsor. A comparison of regionalization and interpolation provided complementary information and revealed that, in different regions, the patterns highlighted by bsor could largely be determined either by nestedness or turnover. Main conclusions Partitioned and unpartitioned indices convey complementary information, and are able to reveal the influence of historical and ecological processes in structuring species assemblages. When the effect of nestedness is strong, the exclusive use of turnover indices can generate geographically coherent groupings, but can also result in the loss of important information. Indeed, various factors, such as colonization-extinction events, climatic parameters and the peninsular effect, may determine dissimilarity patterns expressed by the nestedness component.

  • 103. Dapporto, Leonardo
    et al.
    Voda, Raluca
    Dinca, Vlad
    Stockholm University, Faculty of Science, Department of Zoology. Pompeu Fabra University, Spain; Autonomous University of Barcelona, Spain.
    Vila, Roger
    Comparing population patterns for genetic and morphological markers with uneven sample sizes. An example for the butterfly Maniola jurtina2014In: Methods in Ecology and Evolution, ISSN 2041-210X, E-ISSN 2041-210X, Vol. 5, no 8, p. 834-843Article in journal (Refereed)
    Abstract [en]

    1. Integrating genetic and/or phenotypic traits at population level is considered a fundamental approach in the study of evolutionary processes, systematics, biogeography and conservation. But combining the two types of data remain a complex task, mostly due to the high, and sometimes different, sample sizes required for reliable assessments of community traits. Data availability has been increasing in recent years, thanks to online resources, but it is uncommon that different types of markers are available for any given specimen. 2. We provide new R functions aimed at directly correlating traits at population level, even if data sets only overlap partially. The new functions are based on a modified Procrustes algorithm that minimizes differences between bidimensional ordinations of two different markers, based on a subsample of specimens for which both characters are known. To test the new functions, we used a molecular and morphological data set comprising Mediterranean specimens of the butterfly Maniola jurtina. 3. By using this method, we have been able to maximize similarities between genotypic and phenotypic configurations obtained after principal coordinate analysis for the model species and evaluated their degree of correlation at both individual and population level. The new recluster. procrustes function retained the information of the relative importance of different morphological variables in determining the observed ordinations and preserved it in the transformed configurations. This allowed calculating the best combination of morphological variables mirroring genetic relationships among specimens and populations. Finally, it was possible to analyse the modality and variance of the phenotypic characters correlated with the genetic structure among populations. 4. The genetic and phenotypic markers displayed high overall correlation in the study area except in the contact zone, where discrepancies for particular populations were detected. Interestingly, such discrepancies were spatially structured, with southern populations displaying typical western morphotype and eastern haplotypes, while the opposite occurred in the northern populations. The methodology here described can be applied to any number and type of traits for which bidimensional configurations can be obtained, and opens new possibilities for datamining and formeta-analyses combining existing data sets in biogeography, systematics and ecology.

  • 104. Delling, Bo
    Species diversity and phylogeny of Salmo with emphasis on southern trouts (Teleostei, Salmonidae)2003Doctoral thesis, comprehensive summary (Other academic)
  • 105. Derst, Christian
    et al.
    Dircksen, Heinrich
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Meusemann, Karen
    Zhou, Xin
    Liu, Shanlin
    Predel, Reinhard
    Evolution of neuropeptides in non-pterygote hexapods2016In: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 16, article id 51Article in journal (Refereed)
    Abstract [en]

    Background

    Neuropeptides are key players in information transfer and act as important regulators of development, growth, metabolism, and reproduction within multi-cellular animal organisms (Metazoa). These short protein-like substances show a high degree of structural variability and are recognized as the most diverse group of messenger molecules. We used transcriptome sequences from the 1KITE (1K Insect Transcriptome Evolution) project to search for neuropeptide coding sequences in 24 species from the non-pterygote hexapod lineages Protura (coneheads), Collembola (springtails), Diplura (two-pronged bristletails), Archaeognatha (jumping bristletails), and Zygentoma (silverfish and firebrats), which are often referred to as “basal” hexapods. Phylogenetically, Protura, Collembola, Diplura, and Archaeognatha are currently placed between Remipedia and Pterygota (winged insects); Zygentoma is the sistergroup of Pterygota. The Remipedia are assumed to be among the closest relatives of all hexapods and belong to the crustaceans.

    Results

    We identified neuropeptide precursor sequences within whole-body transcriptome data from these five hexapod groups and complemented this dataset with homologous sequences from three crustaceans (including Daphnia pulex), three myriapods, and the fruit fly Drosophila melanogaster. Our results indicate that the reported loss of several neuropeptide genes in a number of winged insects, particularly holometabolous insects, is a trend that has occurred within Pterygota. The neuropeptide precursor sequences of the non-pterygote hexapods show numerous amino acid substitutions, gene duplications, variants following alternative splicing, and numbers of paracopies. Nevertheless, most of these features fall within the range of variation known from pterygote insects. However, the capa/pyrokinin genes of non-pterygote hexapods provide an interesting example of rapid evolution, including duplication of a neuropeptide gene encoding different ligands.

    Conclusions

    Our findings delineate a basic pattern of neuropeptide sequences that existed before lineage-specific developments occurred during the evolution of pterygote insects.

  • 106.
    Dimitrova, Marina
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Merilaita, Sami
    Prey pattern regularity and background complexity affect detectability of background-matching prey2012In: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 23, no 2, p. 384-390Article in journal (Refereed)
    Abstract [en]

    We investigated how regularity of prey color pattern affects crypsis and how visual complexity of the background affects prey detection. We performed 2 predation experiments with artificial prey and backgrounds, using blue tits (Cyanistes caeruleus) as predators. In experiment 1, we found that contrary to a previous hypothesis, a pattern with repeated background-matching pattern element shapes was not easier to detect than a pattern with variable background-matching shapes. Increased background complexity with respect to shape diversity and complexity made prey detection more difficult. In experiment 2, we tested how spatial regularity of background-matching pattern elements affects crypsis. We found that spatially irregular prey with randomly placed pattern elements were harder to detect on both simple and complex backgrounds compared with spatially regular prey that had the elements aligned. Increased background element shape complexity made both prey categories harder to detect. In conclusion, our study shows that spatial regularity of prey pattern but not regularity due to invariable pattern element shapes deteriorates crypsis. Visually complex backgrounds and specifically those consisting of elements with complex shapes make detection of cryptic prey difficult.

  • 107.
    Dircksen, Heinrich
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Conserved crustacean cardioactive peptide neural networks and functions in arthropod evolution1998In: Recent Advances in Arthropod Endocrinology / [ed] Geoffrey M. Coast, Simon G. Webster, Cambridge: Cambridge University Press, 1998, 65, p. 302-333Chapter in book (Refereed)
  • 108.
    Dircksen, Heinrich
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Crustacean bioactive peptides2013In: Handbook of Biologically Active Peptides / [ed] Abba J. Kastin, New York: Academic Press Elsevier , 2013, 2, p. 209-221Chapter in book (Refereed)
    Abstract [en]

    Research on crustacean peptides has concentrated mainly on decapods and isopods, and a growing number of >200 peptides have been sequenced from these two groups, the majority from decapods, but recently, the annotation of the Daphnia pulexgenome has contributed many more novel peptides many of which were also sequenced de novo. Identified and bioactive crustacean peptides — the only ones reported here — regulate a large range of physiological functions, including color change, activities of heart, exoskeletal and visceral muscles, metabolic function, development, metamorphosis, and reproduction.

  • 109.
    Dircksen, Heinrich
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Neurosecretory endings in the pericardial organs of the shore crab Carcinus maenas L., and their identification by neuropeptide immunocytochemistry1991In: Comparative aspects of neuropeptide function. / [ed] Ernst Florey, George B. Stefano, Manchester, New York: Manchester University Press, 1991, p. 198-200Chapter in book (Other academic)
  • 110.
    Dircksen, Heinrich
    et al.
    University of Bonn, Germany.
    Heyn, Uwe
    Crustacean hyperglycemic hormone-like peptides in crab and locust peripheral intrinsic neurosecretory cells1998In: Annals of the New York Academy of Sciences, ISSN 0077-8923, E-ISSN 1749-6632, Vol. 839, p. 392-394Article in journal (Refereed)
  • 111.
    Dircksen, Heinrich
    et al.
    Rheinische Friedrich-Wilhelms-Universität, Germany.
    Homberg, Uwe
    Crustacean Cardioactive Peptide-immunoreactive neurons innervating brain neuropils, retrocerebral complex and stomatogastric nervous-system of the locust, Locusta migratoria1995In: Cell and Tissue Research, ISSN 0302-766X, E-ISSN 1432-0878, Vol. 279, p. 495-515Article in journal (Refereed)
    Abstract [en]

    The distribution and morphology of crustacean cardioactive peptide-immunoreactive neurons in the brain of the locust Locusta migratoria has been determined. Of more than 500 immunoreactive neurons in total, about 380 are interneurons in the optic lobes. These neurons invade several layers of the medulla and distal parts of the lobula. In addition, a small group of neurons projects into the accessory medulla, the lamina, and to several areas in the median protocerebrum. In the midbrain, 12 groups or individual neurons have been reconstructed. Four groups innervate areas of the superior lateral and ventral lateral protocerebrum and the lateral horn. Two cell groups have bilateral arborizations anterior and posterior to the central body or in the superior median protocerebrum. Ramifications in subunits of the central body and in the lateral and the median accessory lobes arise from four additional cell groups. Two local interneurons innervate the antennal lobe. A tritocerebral cell projects contralaterally into the frontal ganglion and appears to give rise to fibers in the recurrent nerve, and in the hypocerebral and ingluvial ganglia. Varicose fibers in the nervi corporis cardiaci III and the corpora cardiaca, and terminals on pharyngeal dilator muscles arise from two subesophageal neurons. Some of the locust neurons closely resemble immunopositive neurons in a beetle and a moth. Our results suggest that the peptide may be (1) a modulatory substance produced by many brain interneurons, and (2) a neurohormone released from subesophageal neurosecretory cells.

  • 112.
    Dircksen, Heinrich
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Müller, Arno
    Keller, Rainer
    Crustacean cardioactive peptide in the nervous system of the locust, Locusta migratoria: an immunocytochemical study on the ventral nerve cord and peripheral innervation1991In: Cell and Tissue Research, ISSN 0302-766X, E-ISSN 1432-0878, Vol. 263, p. 439-457Article in journal (Refereed)
    Abstract [en]

    Crustacean cardioactive peptide-immunoreactive neurons occur in the entire central nervous system of Locusta migratoria. The present paper focuses on mapping studies in the ventral nerve cord and on peripheral projection sites. Two types of contralaterally projecting neurons occur in all neuromers from the subesophageal to the seventh abdominal ganglia. One type forms terminals at the surface of the thoracic nerves 6 and 1, the distal perisympathetic organs, the lateral heart nerves, and on ventral and dorsal diaphragm muscles. Two large neurons in the anterior part and several neurons of a different type in the posterior part of the terminal ganglion project into the last tergal nerves. In the abdominal neuromers 1–7, two types of ipsilaterally projecting neurons occur, one of which gives rise to neurosecretory terminals in the distal perisympathetic organs, in peripheral areas of the transverse, stigmata and lateral heart nerves. Four subesophageal neurons have putative terminals in the neurilemma of the nervus corporis allati II, and in the corpora allata and cardiaca. In addition, several immunoreactive putative interneurons and other neurons were mapped in the ventral nerve cord. A new in situ whole-mount technique was essential for elucidation of the peripheral pathways and targets of the identified neurons, which suggest a role of the peptide in the control of heartbeat, abdominal ventilatory and visceral muscle activity.

  • 113.
    Dircksen, Heinrich
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Neupert, Susanne
    Predel, Reinhard
    Verleyen, Peter
    Huybrechts, Jurgen
    Strauss, Johannes
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Hauser, Frank
    Stafflinger, Elisabeth
    Schneider, Martina
    Pauwels, Kevin
    Schoofs, Liliane
    Grimmelikhuijzen, Cornelis J. P.
    Genomics, transcriptomics and peptidomics of Daphnia pulex neuropeptides and protein hormones2011In: Journal of Proteome Research, ISSN 1535-3893, E-ISSN 1535-3907, Vol. 10, no 10, p. 4478-4504Article in journal (Refereed)
    Abstract [en]

    We report 43 novel genes in the water flea Daphnia pulex encoding 73 predicted neuropeptide and protein hormones as partly confirmed by RT-PCR. MALDI-TOF mass spectrometry identified 40 neuropeptides by mass matches and 30 neuropeptides by fragmentation sequencing. Single genes encode adipokinetic hormone, allatostatin-A, allatostatin-B, a first crustacean allatotropin, Ala7-CCAP, one CCHamide, Arg7-corazonin, CRF-like (DH52) and calcitonin-like (DH31) diuretic hormones, two ecdysis-triggering hormones, two FIRFamides, one insulin- and one each of three IGF-related peptides, two alternative splice forms of short and long ion transport peptide (ITP), one each of two N-terminally elongated ITPs, myosuppressin, neuroparsin, two neuropeptide-F splice forms, three periviscerokinins (but no pyrokinins), pigment dispersing hormone, proctolin, Met4-proctolin, one novel short neuropeptide-F, three RYamides, SIFamide, two sulfakinins, three tachykinins. Two genes encode orcokinins, three genes different allatostatins-C. Paired gene clusters occur for two novel eclosion hormones; bursicons alpha, beta; glycoproteins GPA2, GPB5; and two of the allatostatin-C genes. Detailed comparisons of genes or their products with those from insects and decapod crustaceans revealed that the D. pulex peptides are often closer to their insect than to their decapod crustacean homologues, confirming that branchiopods, to which Daphnia belongs, are the ancestor group of insects.

  • 114.
    Dircksen, Heinrich
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology. Rheinische Friedrich-Wilhelms Universität, Germany.
    Webster, Simon G.
    School of Biological Sciences University of Wales, Bangor, UK.
    Keller, Rainer
    Immunocytochemical demonstration of the neurosecretory systems containing putative moult-inhibiting hormone and hyperglycemic hormone in the eyestalk of brachyuran crustaceans1988In: Cell and Tissue Research, ISSN 0302-766X, E-ISSN 1432-0878, Vol. 251, p. 3-12Article in journal (Refereed)
    Abstract [en]

    By use of antisera raised against purified moultinhibiting (MIH) and crustacean hyperglycemic hormone (CHH) from Carcinus maenas, complete and distinct neurosecretory pathways for both hormones were demonstrated with the PAP and immunofluorescence technique. By double staining, employing a combination of silver-enhanced immunogold labelling and PAP, both antigens could be visualized in the same section. Immunoreactive structures were studied in Carcinus maenas, Liocarcinus puber, Cancer pagurus, Uca pugilator and Maja squinado. They were only observed in the X-organ sinus gland (SG) system of the eyestalks and consisted of MIH-positive perikarya, which were dispersed among the more numerous CHH-positive perikarya of the medulla terminalis X-organ (XO). The MIH-positive neurons form branching collateral plexuses adjacent to the XO and axons that are arranged around the CHH-positive central axon bundle of the principal XO-SG tract. In the SG, MIH-positive axon profiles and terminals, clustered around hemolymph lacunae, are distributed between the more abundant CHH-positive axon profiles and terminals. Colocalisation of MIH and CHH was never observed. The gross morphology of both neurosecretory systems was similar in all species examined, however, in U. pugilator and M. squinado immunostaining for MIH was relatively faint unless higher concentrations of antiserum were used. Possible reasons for this phenomenon as well as observed moult cycle-related differences in immunostaining are discussed.

  • 115.
    Dircksen, Heinrich
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Wilcockson, Dave C
    Webster, Simon G
    Neuropeptides in a forgotten crustacean neurohaemal organ classic, the postcomissural organs of the shrimp Palaemon serratus2005In: Comparative Biochemistry and Physiology A, ISSN 1095-6433, E-ISSN 1531-4332, Vol. 141, no 3, p. S156-S157Article in journal (Refereed)
  • 116.
    Duplisea, Daniel E.
    Stockholm University, Faculty of Science.
    Structuring of benthic communities, with a focus on size-spectra1998Doctoral thesis, comprehensive summary (Other academic)
  • 117.
    Ejdung, Gunilla
    Stockholm University, Faculty of Science, Department of Zoology.
    Predatory processes in Baltic benthos1998Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The Baltic soft-bottom community is uniquely simple, with only a few benthic macro-faunal species, and is therefore well suited for mechanistic studies of inter-specific interactions. Two of the dominating organisms in this benthic community are the amphipod Monoporeia affinis and the bivalve Macoma balthica. Field surveys have shown that M. balthica is generally absent or scarce when the density of M. affinis is high. The hypothesis that adult M. affinis kill the newly settled bivalves was confirmed experimentally in the laboratory, and it was also shown that adult Pontoporeia femorata amphipods have a negative impact on bivalve survival. Further experiments, showed that juvenile M. affinis, contrary to earlier beliefs, can kill and presumably eat the newly settled M. balthica. The response of M. affinis to increased bivalve densities was a type III like functional response, indicating that bivalves at low densities find a partial refuge from amphipod predation.

    The effect of the predatory isopod Saduria entomon on the Macoma balthica population was assessed both in the laboratory and the field. In the laboratory, the presence of the isopod did not affect the small just settled bivalves (0.3 mm), whereas slightly larger and larger bivalves (>0.8 mm) suffered from increased mortality, as did bivalves in the three month long field study. The isopods are physically capable of opening quite large bivalves, a 34 mm long isopod can break open a 17 mm long bivalve, but given a choice, smaller bivalves are selected. When S. entomon is offered the two prey species, Monoporeia affinis and M. balthica, the amphipod is preferred, leaving the bivalve relatively safe from predation.

    In the aquatic environment, chemical substances released by predators or their activities can convey information, to which prey can respond, for example, by a change in behaviour. In a three-trophic-level food chain, species-specific chemical substances from a predatory fish, the short-horned sculpin (Myoxocephalus scorpius), directly affected the behaviour of the isopod Saduria entomon. The isopod remained buried in the sediment longer, and fewer prey amphipods, Monoporeia affinis, were eaten. Further, exposure to chemical substances from isopods feeding on amphipods, lead the amphipod to lower their swimming activity, whereas water from non-feeding isopods did not have this effect.

  • 118.
    Ekengren, Sophia
    Stockholm University.
    Stress- and immune defence in Drosophila melanogaster2001Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Many cellular responses are regulated at the transcriptional level. Newly synthesized proteins and peptides rapidly exert their function at the time of expression, as a response to different environmental cues. In an attempt to analyze transcriptional activation in response to bacteria, we have identified a novel family of eight stress-induced humoral factors, the Turandot proteins. All Turandot (Tot) genes are induced under stressful conditions such as bacterial infection, heat shock, UV-irradiation and oxidizing agents. One of the members, TotA, is shown to promote increased resistance to the lethal effects of high temperature, indicating that this protein family plays an important role for a systemic stress adaptation.

    This thesis also describes some novel aspects of the Drosophila immune response. Flies mutant for the transcriptional activator, and NF-kB homolog, Relish will not survive a bacterial or fungal infection. Transcriptional characterization shows that the synthesis of antibacterial effector molecules is almost eliminated in these flies. This establishes Relish as the main transcriptional activator for defence against Gram-negative bacteria and fungi.

    I also present novel findings about the antifungal properties of the immune peptide Cecropin A.

  • 119.
    Ekvall, Kenneth
    Stockholm University, Faculty of Science, Department of Zoology.
    Alloparental care and social dynamics in the fallow deer (Dama dama)1999Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In mammals, a sex difference exists in natal dispersal with females remaining in the natal area and males generally leaving the area of birth. Female groups are regarded as the basic social unit of many mammalian species, and in species with overlapping generations groups may develop a matrilineal structure. Under those conditions where daughters remain in their natal area, altruistic and/or co-operative behaviour may be favoured among both close and more distantly related kin.

    This thesis examines the social organisation and occurrence of co-operative behaviours in fallow deer populations in southern Sweden. Social groups were often stable in their constitution during and between years and consisted mostly of close relatives, mainly mothers and their daughters. When daughters gave birth they increased their association with their mothers. Alloparental care such as allosuckling and allogrooming, was common, preferably exhibited by older females toward fawns in the social group. All fawns in the group were given milk from alloparenting females but young females behaved more restrictively and approaching fawns were often met with aggression. Allosuckling attempts from fawns from other groups were not tolerated and met with aggression even from old females.

    Allogrooming, which reduced the number of attached ectoparasites on fawns, was distributed according to relatedness in the stable social unit and not performed towards fawns from other groups. Fawns started to reciprocate both the mother's, other females' and occasionally other fawns' grooming from the age of 8 weeks.

    Allogrooming between adult females was also performed unidirectionally between close kin members of the same group, or reciprocally between members of different groups in a tit for tat manner with a duration evenly matched between the performers. The results seem to support the notion of kin-based groups in fallow deer, with both kin-selected and reciprocal behaviours.

  • 120. Elliott, Kyle H.
    et al.
    Le Vaillant, Maryline
    Stockholm University, Faculty of Science, Department of Zoology. University of Strasbourg .
    Kato, Akiko
    Gaston, Anthony J.
    Ropert-Coudert, Yan
    Hare, James F.
    Speakman, John R.
    Croll, Donald
    Age-related variation in energy expenditure in a long-lived bird within the envelope of an energy ceiling2014In: Journal of Animal Ecology, ISSN 0021-8790, E-ISSN 1365-2656, Vol. 83, no 1, p. 136-146Article in journal (Refereed)
    Abstract [en]

    Energy expenditure in wild animals can be limited (i) intrinsically by physiological processes that constrain an animal's capacity to use energy, (ii) extrinsically by energy availability in the environment and/or (iii) strategically based on trade-offs between elevated metabolism and survival. Although these factors apply to all individuals within a population, some individuals expend more or less energy than other individuals. To examine the role of an energy ceiling in a species with a high and individually repeatable metabolic rate, we compared energy expenditure of thick-billed murres (Uria lomvia) with and without handicaps during a period of peak energy demand (chick-rearing, N=16). We also compared energy expenditure of unencumbered birds (N=260) across 8years exhibiting contrasting environmental conditions and correlated energy expenditure with fitness (reproductive success and survival). Murres experienced an energy ceiling mediated through behavioural adjustments. Handicapped birds decreased time spent flying/diving and chick-provisioning rates such that overall daily energy expenditure remained unchanged across the two treatments. The energy ceiling did not reflect energy availability or trade-offs with fitness, as energy expenditure was similar across contrasting foraging conditions and was not associated with reduced survival or increased reproductive success. We found partial support for the trade-off hypothesis as older murres, where prospects for future reproduction would be relatively limited, did overcome an energy ceiling to invest more in offspring following handicapping by reducing their own energy reserves. The ceiling therefore appeared to operate at the level of intake (i.e. digestion) rather than expenditure (i.e. thermal constraint, oxidative stress). A meta-analysis comparing responses of breeding animals to handicapping suggests that our results are typical: animals either reduced investment in themselves or in their offspring to remain below an energy ceiling. Across species, whether a handicapped individual invested in its own energy stores or its offspring's growth was not explained by life history (future vs. current reproductive potential). Many breeding animals apparently experience an intrinsic energy ceiling, and increased energy costs lead to a decline in self-maintenance and/or offspring provisioning.

  • 121.
    Elmhagen, Bodil
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Åtgärdsprogram för fjällräv 2008-2012 : (Vulpes lagopus) : hotkategori: akut hotad2009Report (Other academic)
  • 122.
    Elmhagen, Bodil
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Eide, Nina E.
    Norén, Karin
    Stockholm University, Faculty of Science, Department of Zoology.
    Killengreen, Siw T.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Wallén, Johan
    Stockholm University, Faculty of Science, Department of Zoology.
    Åtgärdsprogram för fjällräv, 2017–2021 (Vulpes lagopus): Hotkategori: Starkt hotad EN2017Report (Other academic)
  • 123.
    Elmhagen, Bodil
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Hellström, Peter
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Kindberg, Jonas
    Changes in vole and lemming fluctuations in northern Sweden 1960-2008 revealed by fox dynamics2011In: Annales Zoologici Fennici, ISSN 0003-455X, E-ISSN 1797-2450, Vol. 48, no 3, p. 167-179Article in journal (Refereed)
    Abstract [en]

    Cyclic dynamics with extensive spatial synchrony has long been regarded as characteristic of key herbivores at high latitudes. This contrasts to recent reports of fading cycles in arvicoline rodents in boreal and alpine Fennoscandia. We investigate the spatio-temporal dynamics of boreal red fox and alpine arctic fox in Sweden as a proxy for the dynamics of their main prey, voles and Norwegian lemming, respectively. We analyse data from five decades, 1960-2008, with wavelets and autocorrelation approaches. Cyclic dynamics were identified with at least one method in all populations (arctic fox n = 3, red fox n = 6). The dynamics were synchronous between populations, or coupled with a 1-yr lag, in 8 of 13 pairwise comparisons. Importantly though, the dynamics were heterogeneous in space and time. All analytical approaches identified fading cycles in the three arctic fox populations and two northern red fox populations. At least one method identified similar patterns in three southern red fox populations. Red fox dynamics were cyclic in the 1970s primarily, while arctic fox dynamics was cyclic until the late 1980s or early 1990s. When cyclic, 4-yr cycles dominated in arctic fox and northern red fox, whilst 3-4-yr cycles was found in southern red foxes. Significant cyclic regimes reappeared in the 1990s or 2000s in two red fox populations and one arctic fox population. Cycles and regionally coupled dynamics appeared associated in northern arctic and red foxes. This study supports accumulating evidence which suggests that cyclic and synchronous patterns in the dynamics of lemmings and voles are nonstationary in space and time. Furthermore, the similar patterns of change in both fox species indicate that persistence of cycles is governed by similar mechanisms in lemmings and voles.

  • 124.
    Elmhagen, Bodil
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Pasanen-Mortensen, Marianne
    Stockholm University, Faculty of Science, Department of Zoology.
    Världens lodjursarter2014In: Lodjuret / [ed] Roger Bergström, Kjell Danell & Ingvar Svanberg, Stockholm: Atlantis , 2014, p. 9-29Chapter in book (Other (popular science, discussion, etc.))
  • 125.
    Enell, Lina E.
    Stockholm University, Faculty of Science, Department of Zoology.
    Chemical signalling in the Drosophila brain: GABA, short neuropeptide F and their receptors2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Gamma-aminobutyric acid (GABA) and short neuropeptide F (sNPF) are widespread signalling molecules in the brain of insects. In order to understand more about the signalling and to some extent start to unravel the functional roles of these two substances, this study has examined the locations of the transmitters and their receptors in the brain of the fruit fly Drosophila melanogaster using immunocytochemistry in combination with Gal4/UAS technique. The main focus is GABA and sNPF in feeding circuits and in the olfactory system. We found both GABA receptor types in neurons in many important areas of the Drosophila brain including the antennal lobe, mushroom body and the central body complex. The metabotropic GABAB receptor (GABABR) is expressed in a pattern similar to the ionotropic GABAAR, but some distribution differences can be distinguished (paper I). The insulin producing cells contain only GABABR, whereas the GABAAR is localized on neighbouring neurons. We found that GABA regulates the production and release of insulin-like peptides via GABABRs (paper II). The roles of sNPFs in feeding and growth have previously been established, but the mechanisms behind this are unclear. We mapped the distribution of sNPF with antisera to the sNPF precursor and found the peptide in a large variety of interneurons, including the Kenyon cells of the mushroom bodies, as well as in olfactory sensory neurons that send axons to the antennal lobe (paper III). We also mapped the distribution of the sNPF receptor in larval tissues and found localization in six median neurosecretory cells that are not insulin-producing cells, in neuronal branches in the larval antennal lobe and in processes innervating the mushroom bodies (paper IV).

    In summary, we have studied two different signal substances in the Drosophila brain (GABA and sNPF) in some detail. We found that these substances and their receptors are widespread, that both sNPF and GABA act in very diverse systems and that they presumably play roles in feeding, metabolism and olfaction.

  • 126.
    Enquist, Magnus
    et al.
    Stockholm University, Faculty of Humanities, Centre for Cultural Evolution. Stockholm University, Faculty of Science, Department of Zoology.
    Hurd, Peter L.
    Ghirlanda, Stefano
    Stockholm University, Faculty of Humanities, Centre for Cultural Evolution.
    Signaling2010In: Evolutionary Behavioral Ecology / [ed] David F. Westneat, Charles W. Fox, Oxford: Oxford University Press, 2010, p. 266-284Chapter in book (Other academic)
  • 127.
    Envall, Ida
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Erséus, Christer
    Zoologiska institutionen, Göteborgs universitet.
    Gustavsson, Lena
    Avdelningen för evertebratzoologi, Naturhistoriska riksmuseet.
    Ultrastructural investigation of coelomocytes in representatives of Naidinae and Rhyacodrilinae (Annelida, Clitellata, Tubificidae)2008In: Journal of Morphology, Vol. 269, no 9, p. 1157-1167Article in journal (Refereed)
    Abstract [en]

    Various types of free-floating cells are found in the coelomic fluid of representatives of several annelid groups. The ultrastructure of these "coelomocytes," however, has been studied to a limited degree. In this study, we used a transmission electron microscope to investigate the coelomocytes in specimens of five species of Naidinae and three species of Rhyacodrilinae (all oligochaetous clitellates within the family Tubificidae). These were compared with each other and with previously described coelomocytes of representatives of other oligochaete taxa. Only one distinguishable coelomocyte type was found in the studied specimens: a round to oblong cell without pseudopodia or other appendages, primarily containing membrane-bound granules of varying electron density, a prominent network of rough endoplasmic reticulum, and free ribosomes. This type differs to a great extent from most of the previously described coelomocytes, but shows similarities to certain types found in members of Enchytraeidae and Megascolecidae. Although we noticed some variation, we did not find any ultrastructural characters in these cells obviously useful for phylogenetic studies within Tubificidae.

  • 128.
    Envall, Ida
    et al.
    Stockholm University, Faculty of Humanities, Centre for the Study of Cultural Evolution.
    Gustavsson, Lena M.
    Erseus, Christer
    Genetic and chaetal variation in Nais worms (Annelida, Clitellata, Naididae)2012In: Zoological Journal of the Linnean Society, ISSN 0024-4082, E-ISSN 1096-3642, Vol. 165, no 3, p. 495-520Article in journal (Refereed)
    Abstract [en]

    The genus Nais is a group of oligochaetous clitellates, common in eutrophic freshwater habitats. About 30 species are described. Species identification is based primarily on chaetal characters, which are often subtle, inconsistent, and even overlapping between nominal species. We investigated the correlation between genetic variation and chaetal morphology in this genus. Eighty-one individuals from Europe, North America, and China were included in the study. Seventy-five of these were preserved as vouchers. They were scrutinized with regard to chaetal morphology, and ten different morphotypes were identified. Three molecular markers, two mitochondrial (the COI gene and 16S rDNA) and one nuclear (the ITS region), were used to establish the genetic lineages in the material. Genetic variation was found to be largely congruent with chaetal character patterns. However, at least nine separately evolving lineages (all supported by mitochondrial as well as nuclear data) correspond to at most six nominal species. Four morphotypes/lineages are recognized as Nais barbata, Nais christinae, Nais elinguis, and Nais stolci, respectively, whereas five, or possibly more, lineages represent a morphological continuum covering the variation of the Nais communis/variabilis complex. Thus, cryptic speciation is revealed. Our results indicate that a taxonomic revision of the genus will be needed in the future.

  • 129.
    Envall, Ida
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Källersjö, Mari
    Erséus, Christer
    University of Gothenburg.
    Molecular evidence for the non-monophyletic status of Naidinae (Annelida, Clitellata, Tubificidae)2006In: Molecular Phylogenetics and Evolution, ISSN 1055-7903, E-ISSN 1095-9513, Vol. 40, no 2, p. 570-584Article in journal (Refereed)
    Abstract [en]

    Naidinae (former Naididae) is a group of small aquatic clitellate annelids, common worldwide. In this study, we evaluated the phylogenetic status of Naidinae, and examined the phylogenetic relationships within the group. Sequence data from two mitochondrial genes (12S rDNA and 16S rDNA), and one nuclear gene (18S rDNA), were used. Sequences were obtained from 27 naidine species, 24 species from the other tubificid subfamilies, and five outgroup taxa. New sequences (in all 108) as well as GenBank data were used. The data were analysed by parsimony and Bayesian inference. The tree topologies emanating from the different analyses are congruent to a great extent. Naidinae is not found to be monophyletic. The naidine genus Pristina appears to be a derived group within a clade consisting of several genera (Ainudrilus, Epirodrilus, Monopylephorus, and Rhyacodrilus) from another tubificid subfamily, Rhyacodrilinae. These results demonstrate the need for a taxonomic revision: either Ainudrilus, Epirodrilus, Monopylephorus, and Rhyacodrilus should be included within Naidinae, or Pristina should be excluded from this subfamily. Monophyly of four out of six naidine genera represented by more than one species is supported: Chaetogaster, Dero, Paranais, and Pristina, respectively

  • 130.
    Ericson, Gunilla
    Stockholm University, Faculty of Science, Department of Zoology.
    ³²P-postlabelling analysis of DNA adducts in fish as a biomarker of genotoxic exposure1999Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The 32P-postlabelling assay was used for analysis of hydrophobic DNA adducts in fish as a biomarker of genotoxic exposure. DNA adducts were analysed in perch (Perca fluviatilis) and northern pike (Esox lucius), two relatively stationary fish species which are common in Swedish freshwater systems and along the Baltic coast. Experimental studies on time-course, dose-response and persistence of DNA adducts in liver and extrahepatic tissues of pike were performed in the laboratory. DNA adducts were readily formed in pike exposed to carcinogenic model substances. Oral exposure gave rise to higher adduct levels in both liver and intestine compared to intraperitoneal exposure. Following repeated oral exposure, adduct levels increased in a dose-related manner in liver, gills, brain and intestine, with highest levels in the intestine. No significant decrease in total adduct levels was observed in liver, gills and brain during a 78-day period after the last exposure, while adduct levels in intestine decreased to one third of the maximum value. DNA adducts in the intestine are probably removed due to a high cell turnover rate in this tissue, and may thus represent ongoing or relatively recent exposure.

    Perch and pike from minimally polluted sites were analysed at several occasions, including during the reproductive season for perch, with the results showing no detectable adducts, or very low levels. No adducts related to spawning season were detected in unexposed female or male perch.

    In a field investigation carried out in a pollution gradient of polycyclic aromatic hydrocarbons leading away from an aluminium smelter, adduct levels in liver and kidney were correlated to distance from the suspected point source and to contaminant levels in the sediment. Adduct levels in gills, spleen, blood and brain were also elevated in perch from the site closest to the smelter compared to the outermost site. Increased adduct levels in these tissues were correlated to effects on higher biological organisation levels, i.e. hepatocellular degeneration and decreased growth rate at the two innermost sites, and decreased spleen somatic index at the innermost site. Adduct levels were also increased in perch from a river with creosote-contaminated bottom sediments, indicating that potentially genotoxic compounds in the sediment were bioavailable to the fish. Exposure of perch in the laboratory to a solvent extract prepared from the contaminated sediment resulted in adduct patterns which closely resembled those obtained from field captured perch, thus verifying the origin of the genotoxic substances. Furthermore, increased DNA adduct levels in liver and intestine of feral fish from coastal waters receiving bleached kraft pulp mill effluents were detected.

    The results show that 32P-postlabelling analysis of hydrophobic DNA adducts in feral perch and pike can be used as a sensitive biomarker of exposure to potentially genotoxic compounds in the aquatic environment. Adduct levels in liver and several extrahepatic tissues were positively correlated to exposure concentrations. Levels of aromatic/hydrophobic DNA adducts in unexposed perch and pike can be considered as practically zero. DNA adducts thus exhibit a wide range in response, from almost zero in unexposed fish to high levels in exposed fish, which is desirable for a good biomarker.

  • 131.
    Eriksson, Maertha
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Nylin, Sören
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Insect brain plasticity: effects of olfactory input on neuropil size2019In: Royal Society Open Science, E-ISSN 2054-5703, Vol. 6, no 8, article id 190875Article in journal (Refereed)
    Abstract [en]

    Insect brains are known to express a high degree of experience-dependent structural plasticity. One brain structure in particular, the mushroom body (MB), has been attended to in numerous studies as it is implicated in complex cognitive processes such as olfactory learning and memory. It is, however, poorly understood to what extent sensory input per se affects the plasticity of the mushroom bodies. By performing unilateral blocking of olfactory input on immobilized butterflies, we were able to measure the effect of passive sensory input on the volumes of antennal lobes (ALs) and MB calyces. We showed that the primary and secondary olfactory neuropils respond in different ways to olfactory input. ALs show absolute experience-dependency and increase in volume only if receiving direct olfactory input from ipsilateral antennae, while MB calyx volumes were unaffected by the treatment and instead show absolute age-dependency in this regard. We therefore propose that cognitive processes related to behavioural expressions are needed in order for the calyx to show experience-dependent volumetric expansions. Our results indicate that such experience-dependent volumetric expansions of calyces observed in other studies may have been caused by cognitive processes rather than by sensory input, bringing some causative clarity to a complex neural phenomenon.

  • 132.
    Erlandsson, Rasmus
    Stockholm University, Faculty of Science, Department of Zoology.
    Spatial and temporal population dynamics in the mountain tundra – mesopredator and prey2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    It is well known that competition, predation and fluctuating food resources can have strong effect on individual fitness and population dynamics. The complexity of natural systems can make it complicate to disentangle those processes, but environments with relatively simple food webs, and strong cyclic population dynamics offer contrasting conditions resembling experimental treatments. This thesis concerns the spatial and temporal implications of fluctuations in small rodent abundance on two trophic levels in a highly cyclic ecosystem, the Scandinavian mountain tundra. The first two chapters focus on plant biomass and spatiotemporal distribution in the Norwegian lemming (Lemmus lemmus), while the three last papers focus on the direct and indirect effects of small rodent fluctuations and territory quality on reproductive success, juvenile survival and group living in a lemming specialist mesopredator, the arctic fox (Vulpes lagopus). By developing, validating and applying a novel application of aerial photos for remote sensing of plant biomass (Chapter I), we found that food availability predicted lemming distribution during population peaks, but that they were more habitat specific during increase years when intraspecific competition was lower (Chapter II). Arctic fox reproduction is tightly connected to small rodent abundance but the effects of geographical variation in food availability is less well known. We used 17 years of population surveys of an arctic fox subpopulation in mid Sweden (Helagsfjällen) to investigate potential effects. During small rodent increase years, we found that arctic fox litter sizes were smaller in territories of intermediate plant productivity, compared to both more and less productive territories (Chapter III). This could be an effect of limited food availability together with increased presence of red foxes (Vulpes vulpes), a stronger and potentially lethal competitor. However, when small rodents peaked, and competition would be expected to decrease, we saw no effect of territory productivity. Based on a smaller data set concerning juvenile summer survival, we found that the mortality rate among juveniles born by first time breeding arctic fox females were more sensitive to low small rodent prey abundance (Chapter IV). We explain it with an increased predation pressure from top-predators that switch from small rodents to alternative prey when small rodents decline, as suggested by an observed positive effect on juvenile survival by adult presence on den sites. Arctic foxes are socially flexible, and several adults can share a den with the resident pair, potentially increasing juvenile survival and help in territorial defence. Returning to the 17-year data set, we tested the Resource Dispersion Hypothesis predicting that increased resource availability should increase group size (Chapter V). We found support for this prediction as group living increased during the small rodent peak phase. However, it remained unexpectedly high during the decrease phase, when resources are scarce. This could however be related to increased predation pressure, and an increasing benefit of group living.

  • 133.
    Erlandsson, Rasmus
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Norén, Karin
    Stockholm University, Faculty of Science, Department of Zoology.
    Wallén, Johan
    Stockholm University, Faculty of Science, Department of Zoology.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Märkningen av fjällrävar förutsättning för effektiv och långsiktig forskning2015In: Härjedalen, ISSN 1103-9426, no 27 augustiArticle in journal (Other (popular science, discussion, etc.))
  • 134.
    Espeland, Marianne
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Systematic Zoology.
    Irestedt, Martin
    Swedish Museum of Natural History, Molecular Systematics Laboratory.
    Johanson, Kjell Arne
    Swedish Museum of Natural History, Entomology department.
    Åkerlund, Monika
    Swedish Museum of Natural History, Research Department.
    Bergh, Jan-Erik
    Dalarna University College.
    Källersjö, Mari
    Swedish Museum of Natural History, Molecular Systematics Laboratory.
    Dichlorvos exposure impedes extraction and amplification of DNA from insects in museum collections2010In: Frontiers in Zoology, ISSN 1742-9994, E-ISSN 1742-9994, Vol. 7, no 2, p. 1-8Article in journal (Refereed)
    Abstract [en]

    Background: The insecticides dichlorvos, paradichlorobenzene and naphthalene have been commonly used to eradicate pest insects from natural history collections. However, it is not known how these chemicals affect the DNA of the specimens in the collections. We thus tested the effect of dichlorvos, paradichlorobenzene and naphthalene on DNA of insects (Musca domestica) by extracting and amplifying DNA from specimens exposed to insecticides in two different concentrations over increasing time intervals.

    Results: The results clearly show that dichlorvos impedes both extraction and amplification of mitochondrial and nuclear DNA after relatively short time, whereas paradichlorobenzene and naphthalene do not.

    Conclusion: Collections treated with paradichlorobenzene and naphthalene, are better preserved concerning DNA, than those treated with dichlorvos. Non toxic pest control methods should, however, be preferred due to physical damage of specimens and putative health risks by chemicals.

  • 135.
    Espeland, Marianne
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Systematic Zoology.
    Johanson, Kjell Arne
    A new species of Goera Stephens: 1829 (Goeridae Trichoptera) from the Solomon Islands2011In: Aquatic Insects, ISSN 0165-0424, E-ISSN 1744-4152, Vol. 33, no 2, p. 185-189Article in journal (Refereed)
    Abstract [en]

    Male and female of Goera pitisopai sp. nov. from the Solomon Islands are illustrated and described based on recently collected material. This is the first species of the family Goeridae reported from the Solomon Islands, and the sixth from the Australasian region.

  • 136.
    Espeland, Marianne
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Systematic Zoology.
    Johanson, Kjell Arne
    Swedish Museum of Natural History, Entomology department.
    The diversity and radiation of the largest monophyletic animal group on New Caledonia (Trichoptera: Ecnomidae: Agmina)2010In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 23, no 10, p. 2112-2122Article in journal (Refereed)
    Abstract [en]

    In area, New Caledonia is the smallest of the world's 25 official biodiversity hotspots, but in many taxonomic groups, the island has the highest concentration of species on earth, particularly so in the freshwater insect order Trichoptera. This study aims at applying molecular data and morphology for estimating the real species diversity of the genus Agmina on New Caledonia and investigating potential effects of ultramafic rock substrate on diversification. A dated molecular phylogeny was applied to study diversity and diversification related to geological substrate using the dispersal-extinction-cladogenesis model, diva and Bayesian ancestral character reconstruction. More than 47 species (> 63%) were unknown to science. Initial radiation occurred on ultramafic substrate followed by several independent dispersal events to nonultramafic substrate. The rate of shift from ultramafic to nonultramafic substrate was significantly higher than the rate of shift in the opposite direction, indicating a possible cost associated with living on ultramafic substrate.

  • 137.
    Fang Kullander, Fang
    Stockholm University, Faculty of Science, Department of Zoology.
    Phylogeny and species diversity of the South and Southeast Asian cyprinid genus Danio Hamilton (Teleostei, Cyprinidae)2001Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Danio Hamilton, in the wide sense, consists of 66 nominal species, of which about 45 are valid. Four species, viz. D. kakhienensis, D. laoensis, D. shanensis and D. browni, were revalidated in papers revising the genus. Six species were found to be new to science: Danio maetaengensis from northern Thailand; D. kyathit from northern Myanmar; D. apopyris, D. acrostomus and D. leptos form northern Laos; and D. roseus from northeastern Thailand and northwestern Laos. Daniops myersi was confirmed to be a junior synonym of D. laoensis.

    Three species groups have been recognized among Danio (s. l.) species based mainly on colour pattern and other morphological characters: the striped danios, the barred danios and the Danio dangila species group. The striped danios differ from barred danios in having more branched dorsal-fin rays, a complete lateral line, two pairs of short barbels and a P stripe extending to the end of the caudal-fin rays (instead of the P stripe being confined to the caudal peduncle).

    A few characters common to both striped and barred danios but absent in the Danio dangila species group are, e. g., a cleithral spot immediately behind the gill-opening and a skin groove on the supraorbital shelf. A phylogenetic analysis shows that Danio is paraphyletic. Two monophyletic groups can be recognized within the non-monophyletic genus Danio, one comprising only the Danio dangila species group, and the other including all the striped and barred danios. The first group thus represents the genus Danio (s. str.), and the latter a distinct genus Devario, with the type species D. devario. The monophyly of Danio is strongly supported, and its sister group is Esomus. Chela and Inlecypris are closely related to each other, and they form the sister group of Devario. Brachydanio is confirmed to be a junior synonym of Danio (s. str.). Danio erythromicron is excluded from both Danio (s. str.) and Devario. Its generic status is pending further study. The phylogenetic relationships of Sundadanio axelrodi and Danionella translucida to Danio (s. str.) and Devario remain unresolved. 

  • 138.
    Favati, Anna
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Leimar, Olof
    Stockholm University, Faculty of Science, Department of Zoology.
    Løvlie, Hanne
    Personality predicts social dominance in male domestic fowl2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 7, article id e103535Article in journal (Refereed)
    Abstract [en]

    Individuals in social species commonly form dominance relationships, where dominant individuals enjoy greater access to resources compared to subordinates. A range of factors such as sex, age, body size and prior experiences has to varying degrees been observed to affect the social status an individual obtains. Recent work on animal personality (i.e. consistent variation in behavioural responses of individuals) demonstrates that personality can co-vary with social status, suggesting that also behavioural variation can play an important role in establishment of status. We investigated whether personality could predict the outcome of duels between pairs of morphologically matched male domestic fowl (Gallus gallus domesticus), a species where individuals readily form social hierarchies. We found that males that more quickly explored a novel arena, or remained vigilant for a longer period following the playback of a warning call were more likely to obtain a dominant position. These traits were uncorrelated to each other and were also uncorrelated to aggression during the initial part of the dominance-determining duel. Our results indicate that several behavioural traits independently play a role in the establishment of social status, which in turn can have implications for the reproductive success of different personality types.

  • 139. Felton, Adam
    et al.
    Lindbladh, Matts
    Elmberg, Johan
    Felton, Annika M.
    Andersson, Erik
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Sekercioglu, Cagan H.
    Collingham, Yvonne
    Huntley, Brian
    Projecting impacts of anthropogenic climatic change on the bird communities of southern Swedish spruce monocultures: will the species poor get poorer?2014In: Ornis Fennica, ISSN 0030-5685, Vol. 91, no 1, p. 1-13Article in journal (Refereed)
    Abstract [en]

    The potential impact of climatic change on bird species' distributions in Europe was recently modeled for several scenarios of projected late 21st century climate. The results indicate mean range shifts of hundreds of kilometres north for many of European bird species. Here we consider the implications from such distributional shifts for the bird communities of Norway spruce (Picea abies) monocultures in southern Sweden, a forest type likely to remain prevalent due to forestry, despite climate change. Our assessment led us to three key findings. First, the monocultures offer suitable habitat to only two bird species projected to extend their breeding distribution northwards into southern Sweden this century. Second, species richness was projected to decline overall, which would accentuate the depauperate nature of these stands. Third, all conifer-associated arboreal granivores and three of four conifer-associated arboreal insectivores were projected not to occur, reducing both the functional richness and functional redundancy. We discuss caveats related to our approach, including the potential for bioclimatic projections - used in this study - to be hampered by the artificial retention of dominant vegetation. We also discuss the implications of our results for avian biodiversity in what is today the most prevalent forest type in southern Sweden and in many other regions of Europe.

  • 140.
    Fransson, Thord
    Stockholm University, Faculty of Science, Department of Zoology.
    Time and energy in long-distance bird migration1997Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Long-distance seasonal migration is energetically demanding and time consuming. For example, some passerine birds are on migration during six months of the year, travel more than 10 000 km and make use of many fuelling sites. Migration requires many different decisions, and an individual bird will face a variety of situations. This thesis investigates how long-distance migratory passerine birds use time and energy under different circumstances.

    In a comparison of Sylvia warblers, it was shown that more northern populations within species spend shorter time at breeding grounds and have a higher speed during autumn migration. Higher overall speed was also shown in species undertaking longer migrations. This indicates that selection has favoured a behaviour that will economise time during long-distance migration. Results from the last part of the spring migration in the Ortolan Bunting Emberiza hortulana indicate that early arrival is important in males while females might take other considerations into account. Willow Warbler Phylloscopus trochilus males arriving at breeding sites following spring migration carried an overload of fuel, which might be important during the transition between migration and breeding. Since acquisition of this reserve probably delayed their arrival, it also indicates that an individual's future activities have to be considered at some stages of migration.

    Whitethroats Sylvia communis with access to food ad libitum at the start of autumn migration increased their fuel deposition rate and departed with a larger fuel load. At the feeder, no correlation between fuel deposition rate and departure fuel load was found, which is theoretically expected for birds minimising time on migration. Juvenile birds in post-juvenile moult attained a much higher stable body mass at the feeder than under natural conditions. Before departure they abruptly increased their gross food intake by about 70% resulting in a period of body mass gain. Whitethroat behaviour at the feeder agreed with predictions in a finite-distance model for time-minimisation during migration, in which birds take the total migratory distance into account. However, both the compensatory increase in migration speed in late birds that was found in several Sylvia warblers, and the higher departure fuel loads found in late Whitethroats at the feeder indicate that early birds also take other considerations than time-minimisation into account.

    The effect of increased fuel load on the take-off ability under a simulated predator attack in Blackcaps Sylvia atricapilla, was shown to be much less than previously shown for other species. The large fuel loads that often exist, and the intense foraging normally combined with fuelling, will probably still place them at increased risk of predation during migration. In a simulated stopover situation, Blackcaps with an imminent risk of predation initially increase their food intake and fuelling rate compared with a control group. The pattern of night activity indicated that they also choose to leave earlier and with a lower fuel load than birds in the control group. This clearly shows that stopover behaviour can be adjusted to perceived predation risk.

    Evolution is expected to favour a behaviour where survival is maximised during migration. However, it is not always possible to maximise behaviour and performance in all respect simultaneously. It is suggested that the optimal migration strategy may be to minimise overall mortality risk, achieved through a balance between consequences of arrival time, starvation risk and exposure to predation during migration

  • 141.
    Fransson, Thord
    et al.
    Naturhistoriska Riksmuseet.
    Jakobsson, Sven
    Stockholm University, Faculty of Science, Department of Zoology.
    Johansson, Patrik
    Sveriges geologiska undersökningar.
    Kullberg, Cecilia
    Stockholm University, Faculty of Science, Department of Zoology.
    Lind, Johan
    Stockholm University, Faculty of Science, Department of Zoology.
    Valllin, Adrian
    Stockholm University, Faculty of Science, Department of Zoology.
    Magnetic cues trigger extensive refuelling2001In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 414, p. 35-36Article in journal (Refereed)
  • 142.
    Fredriksson, Magnus J.
    Stockholm University.
    β-adrenergic stimulation of VEGF gene expression: intracellular signalling pathways2001Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In the present study, the intracellular signalling pathway mediating ß-adrenergic stimulation of the expression of the vascular endothelial growth factor (VEGF) gene was investigated.

    VEGF is an activator of angiogenesis, the formation of new blood vessels, and is considered to be a major regulator of both physiologically and pathologically related angiogenesis, as well as being essential for development of the vascular system. At the outset of the present investigation, it was already known that several factors - such as hypoxia, certain growth factors and phorbol esters - were potent stimulators of Vegf expression; however, it was unknown whether activation of ß-adrenergic receptors could influence the expression of the VEGF gene. Thus, to investigate this issue, cultured primary brown adipocytes, which express ß-adrenergic receptors, were isolated from mouse brown adipose tissue and used as a model system. The present cell system is here thought of as a relevant model for elucidation of angiogenesis-related processes - such as regulation of Vegf expression - since brown adipose tissue is a highly vascularised tissue, demonstrating high angiogenesis activity during tissue recruitment which is induced as a response to cold exposure or norepinephrine stimulation.

    With Ucp1-ablated mice - the brown adipocytes of which were demonstrated to lack the capacity for adrenergically induced oxygen consumption (thermogenesis) - results were obtained that provide support for the idea that the physiological activator of ß-adrenergic receptors, norepinephrine, is the factor that directly mediates physiological stimulation of Vegf expression in brown adipose tissue during recruitment, i.e. without involvement of hypoxic conditions being generated in the tissue.

    It was demonstrated that norepinephrine-induced activation of ß-adrenergic receptors mediates a potent stimulation of Vegf expression in brown adipocytes. For elucidation of the intracellular signalling factors activated via the ß-receptors, differentiated brown adipocytes, which possess ß3-adrenergic receptors, were used. It was found that for mediation of the ß-adrenergic signal, high intracellular levels of cAMP, and subsequent activation of PKA, are the exclusive mediating pathway for adrenergic stimulation; involvement of other adrenergic signalling mechanisms were excluded. In connection with investigations of PKA-mediated signalling via ß3-adrenergic receptors, the PKA inhibitor H89 was used and it was concluded that it functioned as intended - to abolish ß3-adrenergically induced Vegf and Ucp1 expression and thermogenesis by PKA inhibition - and did not act as a ß3-adrenergic antagonist.

    Further, adrenergic activation of the Erk1/2 MAP kinase signalling pathway in brown adipocytes was elucidated and shown to proceed through Src tyrosine kinases. ß-Adrenergic activation of Src, via a cAMP/PKA-mediated pathway, was demonstrated to partially mediate ß-adrenergic stimulation of Vegf expression, without dependence on further mediation via the downstream-acting Erk1/2, thus indicating a branch-point in the ß-adrenergically activated Src-Erk1/2 signalling cascade which further connects to the VEGF gene.

    In conclusion, the present investigation has provided further insight into the mechanisms by which stimulation of Vegf expression can be mediated, and has contributed information on the involvement of ß-adrenergic receptors in this process.

  • 143. Freeberg, Todd M.
    et al.
    Krama, Tatjana
    Vrublevska, Jolanta
    Krams, Indrikis
    Kullberg, Cecilia
    Stockholm University, Faculty of Science, Department of Zoology.
    Tufted titmouse (Baeolophus bicolor) calling and risk-sensitive foraging in the face of threat2014In: Animal Cognition, ISSN 1435-9448, E-ISSN 1435-9456, Vol. 17, no 6, p. 1341-1352Article in journal (Refereed)
    Abstract [en]

    Individuals often produce alarm or mobbing calls when they detect a threat such as a predator. Little is known about whether such calling is affected by the facial orientation of a potential threat, however. We tested for an effect of facial orientation of a potential threat on tufted titmice, Baeolophus bicolor, a songbird that uses chick-a-dee calls in a variety of social contexts. In two studies, a human observer wore an animal mask that either faced or faced away from the focal bird(s). In Study 1, focal birds were individual titmice captured in a walk-in trap, and the observer stood near the trapped bird. In Study 2, focal birds were titmouse flocks utilizing a feeding station and the observer stood near the station. In both studies, calling behavior was affected by mask orientation. In Study 2, foraging and agonistic behavior were also affected. Titmice can therefore perceive the facial orientation of a potential threat, and this perception affects different behavioral systems, including calling. Our results indicate sensitivity of titmice to the facial orientation of a potential predator in two quite different motivational contexts. This work suggests the possibility of strategic signaling by prey species depending upon the perceptual space of a detected predator.

  • 144. Freitas, André
    et al.
    Peña, Carlos
    Stockholm University, Faculty of Science, Department of Zoology. Zoologisk ekologi.
    Description of genus Guaianaza for "Euptychia" pronophila (Lepidoptera: Nymphalidae: Satyrinae) with a description of the immature stages2006In: Zootaxa, ISSN 1175-5326, E-ISSN 1175-5334, Vol. 1163, p. 49-59Article in journal (Refereed)
    Abstract [en]

    The satyrine Euptychia pronophila Butler (Nymphalidae) was described in 1867 in the “catch-all” genus Euptychia, but was recently treated as incertae sedis. A DNA-based cladistic analysis confirms that it belongs to the Euptychiina, as sister to Forsterinaria and closely related to Taygetis, Posttaygetis, Parataygetis, Pseudodebis, and Harjesia. Although immature morphology also suggests that this species is closely related to Forsterinaria, none of the adult morphological synapomorphies for the genera in the aforementioned clade occur in E. pronophila, a highly autapomorphic species. Because we were unable to place it with confidence in an established genus, the monotypic satyrine genus Guaianaza Freitas & Peña New Genus is described, with Euptychia pronophila Butler as the type species

  • 145.
    Friberg, Magne
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Aalberg Haugen, Inger M.
    Stockholm University, Faculty of Science, Department of Zoology.
    Dahlerus, Josefin
    Stockholm University, Faculty of Science, Department of Zoology.
    Gotthard, Karl
    Stockholm University, Faculty of Science, Department of Zoology.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology.
    Asymmetric life-history decision-making in butterfly larvae2011In: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 165, no 2, p. 301-310Article in journal (Refereed)
    Abstract [en]

    In temperate environments, insects appearing in several generations in the growth season typically have to decide during the larval period whether to develop into adulthood, or to postpone adult emergence until next season by entering a species-specific diapause stage. This decision is typically guided by environmental cues experienced during development. An early decision makes it possible to adjust growth rate, which would allow the growing larva to respond to time stress involved in direct development, whereas a last-minute decision would instead allow the larva to use up-to-date information about which developmental pathway is the most favourable under the current circumstances. We study the timing of the larval pathway decision-making between entering pupal winter diapause and direct development in three distantly related butterflies (Pieris napi, Araschnia levana and Pararge aegeria). We pinpoint the timing of the larval diapause decision by transferring larvae from first to last instars from long daylength (inducing direct development) to short daylength conditions (inducing diapause), and vice versa. Results show that the pathway decision is typically made in the late instars in all three species, and that the ability to switch developmental pathway late in juvenile life is conditional; larvae more freely switched from diapause to direct development than in the opposite direction. We contend that this asymmetry is influenced by the additional physiological preparations needed to survive the long and cold winter period, and that the reluctance to make a late decision to enter diapause has the potential to be a general trait among temperate insects.

  • 146.
    Friberg, Magne
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. Uppsala universitet.
    Leimar, Olof
    Stockholm University, Faculty of Science, Department of Zoology.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology.
    Heterospecific courtship, minority effects and niche separation between cryptic butterfly species2013In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 26, no 5, p. 971-979Article in journal (Refereed)
    Abstract [en]

    Species interacting in varied ecological conditions often evolve in different directions in different local populations. The butterflies of the cryptic Leptidea complex are sympatrically distributed in different combinations across their Eurasian range. Interestingly, the same species is a habitat generalist in some regions and a habitat specialist in others, where a sibling species has the habitat generalist role. Previous studies suggest that this geographically variable niche divergence is generated by local processes in different contact zones. By varying the absolute and relative densities of Leptidea sinapis and Leptidea juvernica in large outdoor cages, we show that female mating success is unaffected by conspecific density, but strongly negatively affected by the density of the other species. Whereas 80% of the females mated when a conspecific couple was alone in a cage, less than 10% mated when the single couple shared the cage with five pairs of the other species. The heterospecific courtships can thus affect the population fitness, and for the species in the local minority, the suitability of a habitat is likely to depend on the presence or absence of the locally interacting species. If the local relative abundance of the different species depends on the colonization order, priority effects might determine the ecological roles of interacting species in this system.

  • 147.
    Friberg, Magne
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology. Stockholm University, Faculty of Science, Department of Zoology.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology. Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Nya rön om skogs- och ängsvitvingar: Vem är vem i fjärilsvärlden?2009In: Flora och Fauna, Vol. 104, no 1, p. 12-17Article, review/survey (Other (popular science, discussion, etc.))
  • 148. Fridberg, Gunnar
    Morphological studies on the caudal neurosecretory system in teleosts and elasmobranchs.1963Doctoral thesis, comprehensive summary (Other academic)
  • 149.
    Gamberale-Stille, Gabriella
    Stockholm University, Faculty of Science, Department of Zoology.
    On the evolution and function of aposematic coloration2000Doctoral thesis, comprehensive summary (Other academic)
  • 150.
    Gamberale-Stille, Gabriella
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Balogh, Alexandra C. V.
    Stockholm University, Faculty of Science, Department of Zoology.
    Tullberg, Birgitta S.
    Stockholm University, Faculty of Science, Department of Zoology.
    Leimar, Olof
    Stockholm University, Faculty of Science, Department of Zoology.
    FEATURE SALTATION AND THE EVOLUTION OF MIMICRY2012In: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 66, no 3, p. 807-817Article in journal (Refereed)
    Abstract [en]

    In Batesian mimicry, a harmless prey species imitates the warning coloration of an unpalatable model species. A traditional suggestion is that mimicry evolves in a two-step process, in which a large mutation first achieves approximate similarity to the model, after which smaller changes improve the likeness. However, it is not known which aspects of predator psychology cause the initial mutant to be perceived by predators as being similar to the model, leaving open the question of how the crucial first step of mimicry evolution occurs. Using theoretical evolutionary simulations and reconstruction of examples of mimicry evolution, we show that the evolution of Batesian mimicry can be initiated by a mutation that causes prey to acquire a trait that is used by predators as a feature to categorize potential prey as unsuitable. The theory that species gain entry to mimicry through feature saltation allows us to formulate scenarios of the sequence of events during mimicry evolution and to reconstruct an initial mimetic appearance for important examples of Batesian mimicry. Because feature-based categorization by predators entails a qualitative distinction between nonmimics and passable mimics, the theory can explain the occurrence of imperfect mimicry.

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