3 RESULTS
3.1 | Comparative analysis of digestive enzymes activity
The feeding habits affected differently the digestive enzymes activities of the four fish species in the hepatopancreas and intestine (p< .05; Table 1). The carnivorous fish (S. chuatsi ) had higher trypsin and pancrelipase activities in the hepatopancreas and enteropeptidase in the intestine than herbivorous (C. idella ), omnivorous (C. auratus ) and the filter-feeder fish (S. grahami ) (p < .05). Moreover, the filter-feeder fish had higher trypsin and pancrelipase activities in the hepatopancreas but lower entero-amylase in the intestine than the herbivorous and omnivorous fishes (p < .05). The omnivorous fish had significantly higher enteropeptidase activity in the intestine than herbivorous and filter-feeder fishes (p < .05). However, the herbivorous and omnivorous fish species had no significant difference in trypsin and pancrelipase activities in the hapatopancreas (p > .05). Similarly, the herbivorous and filter-feeder fishes had no significant difference in enteropeptidase activity in the intestine (p > .05).
Interestingly, the carnivorous fish (S. chuatsi ) had significantly lower amylopsin activity in the hapatopancreas and entero-amylase in the intestine than the herbivorous, omnivorous and filter-feeder fishes (p < .05). Similarly, the omnivorous fish had significantly lower amylopsin activity than herbivorous and filter feeding fishes in the hepatopancreas (p< .05). The herbivorous and filter feeding fishes had no significant difference in amylopsin activity in the hepatopancreas (p > .05). Equally, herbivorous and filter-feeder fishes had no significant difference in enteropeptidase in the intestine (p > .05). The herbivorous and omnivorous had significantly higher intestinal lipase activity than filter feeder and carnivorous fish species (p < .05). Similarly, the carnivorous fish had significantly higher intestinal lipase than the filter-feeder fish (p < .05). The filter-feeder fish had significantly lower entero-amylase activity than herbivorous and omnivorous fishes in the intestine (p < .05). However, the herbivorous and omnivorous fish species had no significant differences in intestinal lipase and entero-amylase activities (p> .05).