The spatiotemporal micro-distribution of fish in the upper Arataye River (French Guyana)

A point abundance sampling technique was used to study the spatiotemporal pattern of distribution of the fishes of the upper stretch of the Arataye river, French Guiana. Electric fishing being useless in such a black water river, a set of nets of three different mesh sizes (10,27 and 40 mm) was used to catch fish in sorne typical river habitats. Five biotopes considered as characteristic were selected, and sampled while water was low (November) and high (July). The catches per unit effort (C.P. U.E.), species richness (S), and species diversity (H') of the fish assemblages of these five biotopes were compared. The distribution of fish species within the various fish assemblages is not random. Most biotopes harbour different species, both at low and high water levels, and many of these communities appear to be ecologically structured both in space and time (Tab. IV). The value of point sampling as a relia ble technique to study fish distribution in the mosaic of habitats of tropical rivers is discusse