Chiang Mai Journal of Science

Objectives of this study were to examine seasonal diet composition and to investigate the length-weight relationships and condition of Pristolepis fasciata (Bleeker, 1851) (Family Nandidae) and Puntius brevis (Bleeker, 1849) (Family Cyprinidae) in Kaeng Lawa, Khon Kaen Province, northeastern Thailand. The types of food consumed varied with season (Chi-square test, P < 0.05). Food items consumed in all season of chironomid larvae (O. Diptera), baetid and caenid mayflies (O. Ephemeroptera), O. Hemiptera, hydroptilid larvae (O. Trichoptera), and insect fragments. The length-weight relationship of fish from the 3 seaons showed an allometric growth pattern. Their coefficient of condition factors were greater than 1, which indicated that they were in a good condition. The results of diet composition and relative gut length indicated that Pr. fasciata is a carnivore and P. brevis is an omnivore.