ABSTRACT
This study investigated the morphometry of chelipeds, growth pattern, as well as the condition factor of selected Macrobrachium species from Ovia River. The study was carried out for three months during which prawn samples were collected every fortnight from landing sites along Ovia River. A total of 641 prawn samples were collected and their morphometric measurements were taken using a digital Vanier Calliper. while weight measurements were taken using a digital scale. The total body weight for female, male, and combined sexes of M. macrobrachion, ranged from 2.85-12.8g, 3.85-31.2g, and 2.85g-31.2g; the total length ranged from 63.85-104.98mm, 67.59-134.68mm, and 63.85-134.68mm; the major cheliped length ranged from 33-59mm, 41-187mm, and 33-187mm; while the major cheliped weight ranged from 0.03-0.15g, 0.03-4g, and 0.03-4g respectively. The total body weight for female, male, and combined sex of M. vollenhovenii, ranged from 2-63.78g, 2.26-114.67g, and 2-114.67g; the total length ranged from 51.29-156.77mm, 8.74-176.5mm, and 8.74-176.5mm; the major cheliped length of ranged from 29-167mm, 35-208mm, and 29-208mm; while the major cheliped weight ranged from 0.03-4g, 0.03-23g, and 0.03-23.00g respectively. The b-value for M. macrobrachion was 2.87, 3.14, and 3.14 for female, male, and combined sexes respectively, while for M. vollenhovenii, it was 3.0, 2.5, and 2.68 for female, male, and combined sexes respectively. The growth pattern of the major and minor chelipeds of both species was negative allometry. Length-length regression analysis of various segments of major and minor chelipeds for female, male, and combined sexes of both species showed positive allometric growth patterns for ischium, merus, and carpus, while propodus showed negative allometric growth. The r-values from Length-Weight and Length-Length regression analysis showed a significant The mean condition factor of both species was greater than 1 for female, male, and combined populations which indicate favourable condition for the prawns.
