Rearing performance and hematological profile of Nile tilapia Oreochromis niloticus FED diet with lemongrass Cymbopogon citratus leaf extract at different concentrations challenged with Pseudomonas aeruginosa

Abstract

Thisrnstudy was conducted to investigate the digestive system development andrnearly feeding activity of Pangasius hybrid larvae. Four crossbreeding program in triplicate were examined between Pangasius hypopthalmusandPangasius nasutus. Results showed that the digestive systems ofrnboth hybrid larvae were poorly developed immediately after hatching. Therndigestive system of the newly hatched larvae consisted of straightrnundifferentiated tube and anus still closed. The gastro intestinal tract, liverrnand pancreas were formed and developed by 2-dAH. The zymogen granules were alsornobserved in the pancreas and thus imply that function of pancreas startedrnbefore the exogenous feeding period. Gastric glands were only present andrnstarted to secrete enzyme on 6-dAH. Artemia were first seen in digestive tract of the larvae at 54-hAH. However, onset of exogenous feeding was detected at 60-hAH, whereas stomach became enlarged with isometricrnepithelium cells, which were different from the elongated cells in thernintestinal part.