Habitat preference,food habits and growth of juveniles ofLates angustifrons andLates mariae (Pisces: Centropomidae) in Lake Tanganyika

Habitat preference of juveniles ofLates angustifrons andLates mariae, endemic fish species in Lake Tanganyika, was investigated in the field and in the laboratory. Both species settle on the grass bed after the post-larval pelagic phase.L. angustifrons preferred the short grass bed composed ofVallismeria sp., whileL. mariae preferred the tall grass bed composed ofPotamogeton schweinfurthii. L. angustifrons always rested near the root, keeping a position parallel to the bottom; dark cross bands on the body may be advantageous as camouflage in the short grass bed. On the other hand,L. mariae always stayed in mid-water, keeping a head-down position parallel to a leaf or stem of grass; such posture and longitudinal stripes on the body may be advantageous as camouflage in the tall grass bed. Both species were more active at night, and fed mainly on atyid shrimps.Lates angustifrons shifted its main food from shrimps to fish with growth, as was suggested inL. mariae. Difference in the habitat preference may play an important role in their coexistence.