Morphometric and meristic characterization of Macrobrachium vollenhovenii in Ogun River, Abeokuta, Nigeria

Abstract

This study was carried out in River Ogun, Abeokuta, Nigeria from February to December, 2014. Samples of Macrobrachium vollenhovenii used in the investigation were collected monthly from artisanal fishermen. The samples were preserved with ice and transported to the laboratory. Weight, total length, carapace length, length of cephalothorax, eye diameter, length of right and left antenna were measured. Others were length of right and left chela, length of uropods, length of rostrum, length of telson, dorsal and ventral rostral spines. Total length and weight of M. vollenhovenii ranged from 8.0 – 18.2 cm (mean = 14.81 ± 0.28 cm) and 6.1 – 105.0 g (mean = 36.48 ± 1.16 g). Though, right chela and antenna were longer than the left, no significant difference (p>0.05) was detected. Negative correlations were observed between length of right chela-eye diameter (-0.11), and length of left chela-eye diameter (-0.04). However, highest correlation (0.96) was detected between total length and weight while the least positive correlation (0.03) exists between eye diameter and length of uropod. Derived b-value of length-weight equation was 3.30, which was not significantly different (p>0.05) from 3. This study provides information on the characterization of M. vollenhovenii which can be used as taxonomic tool for its identification