Aspects of Biology in Round Sardinella, Sardinella aurita (Valenciennes, 1847) from Majidun Creek, Lagos, Nigeria

The present study investigates aspects of the biology of round sardinella, Sardinella aurita (Valenciennes, 1847) from Majidun Creek, Lagos, Nigeria between January and December 2010. S. aurita is a clupeid, a group of fish commonly referred to as sardine. Its fishery is commercially exploited worldwide. A total 256 specimens of S. aurita were caught from Majidun creek at depths between 6-15 meters, with gill and cast nets. The fish abundance was determined monthly; data on fish total length (TL), body weight (BW), eye diameter (ED), head length (HL) and body depth (BD) measurements were obtained from the specimens. The length-weight relationship (LWR), condition factor (K) and sex ratios were estimated using standard methods. Relative abundance showed that 58.20 and 41.80 % of fish were caught in the dry and wet seasons respectively. The species was most abundance (22.27%) in May while July-November 2010 were the meager months. The specimens measured between 10.8 and 17.1(13.72±0.88 cm TL) and weighing 12.32 and 49.91 (22.90±4.71 g body weight) respectively. The morphomeric data included: ED measuring 7-9, 0.7859±0.0789 mm; HL, 3.4-3.9 (3.6829±0.168) mm and BD, 3.4-4.6 (4.0746±0.322) mm. The LWR indicated negative allometric growth (W=-0.733L ), K=0.501-1.56 (0.888±0.159) with females showing better K values. The sex ratio was 1male:1.33 (1.83)