Trophic regime of the giant freshwater shrimp Macrobrachium vollenhoveni (Herklots, 1857) in the lower Oueme valley in Southern Benin

Abstract

The diets of Macrobrachium vollenhoveni are not well known in Benin. This study aims to inventory these diets based on stomach contents. Indeed, measurements of physico-chemical parameters of the habitats, the measurement of morpho-metric lengths and the observation of the stomach contents of shrimps were carried out. Results revealed that pH varied between 6.7- 7.86, oxygen between 4-7 mg/l, temperature between 27.5°-29.1 °C, salinity between 2-5, depth between 0.83-3.82 cm, transparency between18-30 cm, conductivity between 64-69 µS/cm and total dissolved solubles between 33-36 mg/l. From the 27 feed regimes counted, animal (51%) and plant (36%) debris were majority. Clustering of individuals according to station and size class did not influence the variation in diets. The χ2 and Spearman correlation test showed that the proportions of preferred feeds varied significantly (p< 0.05). This study showed that M. vollenhoveni is an omnivorous detritivore whose diet in captivity would be less demanding.