Development of yolk complex, liver and anterior intestine in pike-perch larvae,Stizostedion lucioperca(Percidae), according to the first diet during rearing

Abstract

Pike-perch Stizostedion lucioperca larvae fasted or given two diets (artificial feed, zooplankton) were studied by transmission electron microscopy and using specific cytological dyes. The objective of this work was to assess the changes in the yolk sac, liver and anterior intestine following the mouth opening stage (95 "C.d, day 5 -5.8 mm) from endo-to exotrophy periods. The yolk sac included a syncytial envelope closely bound to the proteinaceous vitellus and the oil globule. Its development was similar to that observed in trout (Oncorhynchus mykiss and Salmo fario trutta) and sea-bream (Sparus aurata), but without vitellus fragmentation into platelets. Vitellus resorption was never achieved in dying larvae. From the end of the endotrophic phase onwards, the amount of hepatic glycogen decreased. Carbohydrate disappeared at the beginning of the exotrophic phase then increased after 220°C.d (day 10 -6.0 mm), mainly in zooplankton-fed larvae. Lipids from enterocytes, sinusoids and general blood Stream showed a similar development. They were abundant at 95 OC.d, progressively disappeared up to 260°C.d (day 12 -6.3 mm), and increased again from 350 "C.d (day 16 -6.7 mm) onwards if larvae were fed zooplankton.Dietary lipids did not seem to immediately replace yolk lipids despite absorption in the gut. Various hypotheses are proposed to explain the physiological abnormalities of this critical larval stage. Although zooplankton appeared to have better nutritional qualities than the artificial feed, these two foods proved to be quite unsatisfactory as they induced liver ce11 changes typical of food deficiency, generally observed in starving larvae.

Effects of weaning age and diets on ontogeny of digestive activities and structures of pikeperch (Sander lucioperca) larvae

“…Few studies have been dedicated to the digestive system ontogeny of pikeperch larvae (Mani-Ponset et al 1994;Ostaszewska 2002;Ostaszewska et al 2005) using histological methods. In this study, we studied both structural and enzymatic development.…”

“…A few authors studied pikeperch larval development (Mani-Ponset et al 1994Diaz et al 1997Diaz et al , 2002 and their studies focused on the evolution of yolk reserves and digestive tract or lipid metabolism during the very early life stages. More recently, Ostaszewska et al (2005) studied the changes in digestive tract of pikeperch larvae fed natural food or commercial diets.…”

The Nature of Exocytosis in the Yolk Trophoblastic Layer of Silver Arowana (Osteoglossum bicirrhosum) Juvenile, the Representative of Ancient Teleost Fishes

“…Other abbreviations: asterisks show lipid vacuoles emptied following alcohol treatment during tissue processing, nucleus (n), oesophagus (oe), pyloric part of the stomach (pc), (#) shows the artifact, present in samples, as the result of different shrinking of soft tissue and massive yolk fluid in the fixatives; Rectangle in 3c refers to 3f-g. Stained with hematoxylin and eosin (3a-d) and (3e) with AB/PAS. Ponset et al, 1994Ponset et al, , 1996. To the contrary, some other fish species do not seem to have stratified ''periblast,'' such as Atlantic cod (Gadus morhua), Atlantic halibut, gilthead sea bream (Sparus aurata), sea bass, and pikeperch (reviewed and summarized by Hoehne-Reitan and Kjørsvik, 2004).…”

“…In fish embryos microvilli were observed in Fundulus (Trinkaus, 1984b) and Prochilodus lineatus (Ninhaus-Silveira et al, 2007). It was postulated by Mani-Ponset et al (1994, 1996 that the microvilli protruded into the perisyncytial (''perivitelline space" according to Mani-Ponset et al, 1994, 1996 circulatory space in gilthead sea bream, sea bass, and pike-perch larvae. However, in these cases, a more folding-like structure was observed, considerably different from the regular, elaborate, high-density microvillar structure described here in arowana.…”

“…Poupard et al (2000) described the process of the utilization of yolk reserves during larval development of turbot (Scophthalmus maximus) and emphasized that the apoE gene expression in the yolk cell is parallel to very lowdensity lipoprotein particles exocytosis into a perisyncytial space. However, a few investigators have addressed the cytological basis of endogenous feeding, particularly utilization of yolk reserves in teleost fish embryos (Shimizu and Yamada, 1980;Sire et al, 1994) and larvae (Vernier and Sire, 1977a,b;Sire and Vernier, 1979;Walzer and Schönenberger, 1979a,b;Kjørsvik and Reiersen, 1992;Mani-Ponset et al, 1994). As much as we know about the roles of the ysl in early development and organogenesis, the structure that correlates with its function in larval/yolksac juvenile of fish development remains unexplored, especially in the most ancient teleost fish, Osteoglossomorpha (Assheton, 1907).…”