Analysis of Condition Metric in Two Macrobrachium Species across Three Lagoon Ecosystems in Southwest Nigeria

Abstract

Macrobrachium species are decapod crustaceans belonging to the infra-order Caridae. These prawn species are found mainly in the Southern part of Nigeria and due to their socio-economic and aquaculture potentials, they have gained a lot of attention, majorly of the biologists. The condition metric (comparison of the weight and length) of brackish water prawn - Macrobrachium macrobrachion and African river prawn - Macrobrachium vollenhovenii were assessed monthly over a period of 24 months (August, 2021 - July, 2023) from Badagry, Epe and Lagos Lagoons. The result showed that a total of 5634 species of the prawns collected from the three lagoons, comprised of 3978 M. macrobrachion (1847 males, 2131 females) and 1656 M. vollenhovenii (1166 males, 490 females). The condition metric (K-value) of the prawn species from the three lagoons ranged between 0.3 and 3.1, with the male species having the highest value. The lowest and highest K-value for M. macrobrachion and M. vollenhovenii were 0.9, 1.7 and 0.3, 3.1 respectively. The K-factor of M. vollenhovenii was higher than that recorded for M. macrobrachion from the study. The results revealed that the condition metric (K) of both prawn species were equal to and greater than 1, indicating that the individuals were in good health across the studied habitats. These findings provide valuable insights for biologists and resource managers, contributing to the sustainable management and conservation of Macrobrachium species within the three lagoon ecosystems.