Distribution patterns of the striped mullet (Mugil cephalus) in mangrove creeks of Zanzibar, Tanzania
(English)Manuscript (Other academic)
Spatial and seasonal variations in density of the striped mullet Mugil cephalus were investigated in four mangrove creeks in Zanzibar (Tanzania) during a one-year cycle. Fish were collected monthly in the lower, intermediate and upper reaches of each creek using a beach seine net (each haul covering 170 m2). All individuals collected were juveniles with a mean size of 2 to 16 cm (standard length). The density of juvenile mullets inhabiting mangrove creeks differed significantly among the different creeks, but the patterns within creeks were consistent, with higher densities upstream in three of the creeks. In general, small-sized juvenile mullets (2-10 cm) were more abundant in the upper reaches compared to the lower and intermediate sites in most creeks. Seasonal patterns were fairly weak, although high mullet densities were observed during the period of heavy rains (from March to May). Principal component analysis (PCA) showed that a muddy bottom with microphytobenthos was likely important to explain high mullet densities, although site-specific variables like low water depth and water clarity may also be important. Our findings suggest that the densities of juvenile striped mullet vary among sites and creeks in response to refuge availability from turbid shallow waters and the accessibility of food resources from benthic microalgae.
Mugil cephalus, Population density, Marine embayment, Spatial and seasonal variation, Zanzibar Island
Fish and Aquacultural Science
Research subject Animal Ecology
IdentifiersURN: urn:nbn:se:su:diva-27396OAI: oai:DiVA.org:su-27396DiVA: diva2:214032