Digestive enzyme system of larvae of different freshwater teleosts and its differentiation during the initial phase of exogenous feeding

Abstract

Lahnsteiner F. (2017): Digestive enzyme system of larvae of different freshwater teleosts and its differentiation during the initial phase of exogenous feeding. Czech J. Anim. Sci., 62, 403-416.Activities of digestive enzymes and main histological characteristics of the intestine were investigated in larvae of three salmonid species (Coregonus maraena, C. atterensis, Thymallus thymallus), of burbot (Lota lota), and pikeperch (Sander lucioperca) at the onset of exogenous feeding (0 day degrees (°d)) and at 250°d thereafter. At the onset of exogenous feeding the activities of proteolytic, lipolytic, and carbohydrate splitting enzymes were detected in the intestines of all species. The enzymatic activities showed significant species specific differences indicating specializations in functionality and digestion ability. In C. atterensis and L. lota the activities of most enzymes were low in comparison to the other investigated species and therefore their digestive system was only poorly developed. In S. lucioperca it was moderately developed and in T. thymallus and C. maraena well-developed. After 250°d, the activities of the investigated enzymes changed in a very species specific way. Histologically, the intestines of the investigated species revealed no species specific differentiations at the onset of the first feeding with the exception of the absence of goblet cells in L. lota and C. atterensis. These differentiated after 250°d.

Exploring the potential for an evolutionarily conserved role of the taste 1 receptor gene family in gut sensing mechanisms of fish

“…At this point, enterocytes initiate their apical differentiation by developing a brush border microvillus membrane that becomes fully functional at approximately the third week post-hatching ( Cahu and Zambonino-Infante, 1994 ; Moyano et al., 1996 ; Ribeiro et al., 1999 ; Zambonino-Infante et al., 2008 ). Despite the low degree of morphological differentiation, at mouth opening most fish species investigated so far, including marine ( Zambonino-Infante and Cahu, 2001 ; 2008 ; Rønnestad et al., 2013 ; Yúfera and Darias, 2007 ) and freshwater ( Lahnsteiner, 2017 ) species, have active cytosolic (intracellular; e.g., leucine–alanine peptidases) and secretory (pancreatic, trypsins, lipases and amylases) proteolytic, lipolytic, and carbohydrate splitting enzymes in their intestines. These findings suggest that the onset of digestive enzyme expression and activity is not induced by food but rather genetically hardwired.…”

A method for Rearing Perch, Perca fluviatilis, Larvae Using Paramecium caudatum, Followed by Wild Zooplankton and Formulated Dry Feed in Combination With Adequate Tank Systems

“…In experiment 1 the weaning from Paramecium caudatum to the self-produced formulated dry feed 2 was tested ( Figure 1a). This feed was successfully used for first feeding of larvae with undifferentiated digestive tracts in previous experiments (Lahnsteiner & Kletzl, 2015a, 2015b, 2017. In experiment 2 the weaning from Paramecium caudatum to zooplankton was tested (Figure 1b), and in experiment 3 the weaning from Paramecium caudatum to zooplankton and finally to formulated dry feed ( Figure 1c).…”

Effects of First Feeding Regime on Gene Expression and Enzyme Activity in Pikeperch (Sander lucioperca) Larvae

“…Trypsin is an important indicator of nutritional condition that is directly connected to protein metabolism. Its activity has been detected during the larval development of most studied marine fish (Cahu and Infante, 1995;Nolting et al, 1999;Infante and Cahu, 2001;Garcia-Gasca et al, 2006) and in some freshwater species (Chakrabarti et al, 2006;Silveira et al, 2013;Lahnsteiner, 2017;Palinska-Zarska et al, 2020). Activity of trypsin along with other pancreatic enzymes such as lipase and amylase are generally used as indexes of digestive function and maturation (Infante and Cahu, 1994;Ribeiro et al, 1999;Zambonino Infante and Cahu, 1999;Infante and Cahu, 2001).…”