Stomach Content Analyses of Cassava Croaker Pseudotolithus senegalensis (Valenciennes, 1833) in Forcados River Estuary, Delta State, Nigeria

Abstract

Pseudotolithus senegalensis is one fish species caught in large numbers in Forcados river estuary. Regardless of it's abundance, published information about the biology of this unique species in this water body is scare. This research study would fill the knowledge gaps by providing information for further studies. A total of 1120 samples of P. senegalensis were collected from artisanal fishermen from Forcados river estuary from April 2017 to March 2019. The stomachs of the fish were slit opened and food content were identified and analysed using the frequency of occurrence and volumetric methods. Ivlev index was used to estimate food selectivity. About 96.66% of the stomachs studied had food items. Small fish species recorded 30.39% (highest percentage) by frequency of occurrence analysis and 41.22 % volumetric analysis method. The order of preponderance index from the most important food item revealed the following trend - small fish (56.15 %); shrimps (24.05 %); snails (gastropod) (13.66%), fish scales (4.66 %) and fish bone (1.48 %). The Ivlev index indicated that shrimps were positively selected by the fish. This study provides baseline information on an aspect of biology of cassava croaker. However, more studies on this species are recommended for better understanding of its ecology and possible data comparisons in the future.