Izvorni znanstveni članak
https://doi.org/10.14798/73.4.852
DIETARY SPECTRUM, DISPERSITY AND OVERLAPS OF BLUE CRAB (Callinectes amnicola, DE ROCHEBURNE) FROM SOUTHEAST NIGERIA
James Philip Udoh
; Department of Fisheries and Aquatic Environmental Management, University of Uyo, Akwa Ibom, Nigeria
Ufonima Udo Jimmy
; Department of Fisheries and Aquaculture, University of Agriculture, Makurdi, Benue, Nigeria
Sažetak
Blue crabs Callinectes amnicola are primarily described as carnivores (with more than 70% of animal food content in stomachs), but an assessment of the stomach contents of 239 and 245 crabs from the Qua Iboe River (QIRE) and Imo River estuaries (IRE), respectively, from January – December 2008, indicate the species exhibited a generalist and unspecialized carnivore feeding habit with animal food content <70% (61.15% and 56.03% in QIRE and IRE, respectively) during the study period. Eighteen dietaries in seven main food categories were identified and classified into four trophic levels: nekton (fish bones and scales), detritus (sediments), plants (algae and sea grasses) and zoobenthos (molluscs and insects). Fish and sediments were the primary food resources for QIREcrabs. The dendrogram plot, using cluster analysis, indicated four groups. The crabs from IRE exhibited higher diet generalization, wider diet breadth (feeding on sediments, fish, plants and molluscs), higher feeding intensity and condition factor than those of QIRE. Crabs from both locations exhibited similar dietary quality (index of biotal dispersity, IBD>60%) but dissimilar dietary quantity since diet overlap (< 60%) and diet breadth (B < 1) were low. Hence, crab combines its ability to switch from one food category to another with a tendency for carnivore detritivore in IRE to omnivore-carnivore in QIRE, relative to abundance of food/prey items in its environment.
Ključne riječi
Diet; Crustacea; demersal species; food trophic level
Hrčak ID:
150791
URI
Datum izdavanja:
10.12.2015.
Posjeta: 1.215 *