Developmental changes in digestive enzyme activity in American shad, Alosa sapidissima, during early ontogeny

Abstract

In order to assess the digestive physiological capacity of the American shad Alosa sapidissima and to establish feeding protocols that match larval nutritional requirements, we investigated the ontogenesis of digestive enzymes (trypsin, amylase, lipase, pepsin, alkaline phosphatase, and leucine aminopeptidase) in larvae, from hatching to 45 days after hatching (DAH). We found that all of the target enzymes were present at hatching, except pepsin, which indicated an initial ability to digest nutrients and precocious digestive system development. Trypsin rapidly increased to a maximum at 14 DAH. Amylase sharply increased until 10 DAH and exhibited a second increase at 33 DAH, which coincided with the introduction of microdiet at 30 DAH, thereby suggesting that the increase was associated with the microdiet carbohydrate content. Lipase increased until 14 DAH, decreased until 27 DAH, and then increased until 45 DAH. Pepsin was first detected at 27 DAH and then sharply increased until 45 DAH, which suggested the formation of a functional stomach. Both alkaline phosphatase and leucine aminopeptidase markedly increased until 18 DAH, which indicated intestinal maturation. According to our results, we conclude that American shad larvae possess the functional digestive system before mouth opening, and the significant increases in lipase, amylase, pepsin, and intestinal enzyme activities between 27 and 33 DAH suggest that larvae can be successfully weaned onto microdiets around this age.

Development of digestive enzymatic activity and gene expression during the early ontogeny of Chinese perch (Siniperca chuatsi)

“…At the same time, other digestive enzymes activity decreases since it is in the course of being partly replaced by pepsin activity in the developing stomach [39] . The same pattern was observed in Pagrus major [1,37] , Megalobrama terminalis [17] , Alosa sapidissima [30] , Trachinotus ovatus [32] , Sparidentex hasta [33] ,…”

“…Alosa sapidissima [30] , Anguilla japonica [31] and Trachinotus ovatus [32] . One reason for the presence of the try expression and trypsin activity was detected at hatching before mouth opening in S. chuatsi might be that it is related to a genetically programmed process [1] .…”

Identifying the germ cells during embryogenesis and gametogenesis by germ‐line gene vasa in an anadromous fish, American shad Alosa sapidissima

“…Intriguingly, A. sapidissima exhibits latitudinally correlated variation in reproductive strategies, including semelparity and iteroparity, and becomes a unique model for evaluating the effects of environment factors on germ‐cell behaviour. However, the lack of effective strategies to improve the reproduction and protection of A. sapidissima , its population abundance declined dramatically in the early 20th century and is still depressed, even though extensive management and investigations have been conducted in this fish (Xu et al, ; Raabe & Hightower, ; Gao et al, ). Taken together, knowledge on the development of PGCs and germ‐cell differentiation will benefit the understandings on the reproductive modes and facilitate developing techniques to preserve the genetic resources of wild species, including A. sapidissima .…”

Influence of dietary fatty acid composition on enzymatic activity and digestive histology in silver catfish (Rhamdia quelen)

“…The yolk is the source of energy for the larvae to develop, and at the same time a substrate for the differentiation and growth of new structures (Portella et al, 2012). This is the first food to be metabolized with the help of existing enzymes, the main digestive enzymes produced by the pancreas being trypsin, amylase and lipase that can be detected even before opening the mouth (Gao et al, 2016;Cui et al, 2017). The activity of the acid protease had a gradual increase from 32Haf to 166Haf (Table 2).…”