Testing protein-walled microcapsules for the rearing of first-feeding gilthead sea bream (Sparus aurata L.) Larvae

Abstract

Two basic types of protein-walled microcapsules were developed with the aid of using different preparation techniques. One type (Type A) was spherical and hard-walled, whereas the other (Type G) was irregularly shaped and soft-walled. The present work examined the larval growth and development of Sparus aurata reared either with these microcapsules as the sole food source or with a mixed diet of microcapsules and rotifers from the start of feeding. Larvae fed on Type A microcapsules evacuated them practically intact. These larvae showed strong degeneration of the gut epithelium, liver and pancreas and died within two to three days after the onset of feeding. In contrast, larvae fed from first feeding with Type G microcapsules alone ingested and broke down the particles from the onset of feeding. No larval growth was observed, but some larvae were still alive at the end of the experiment (Day 13). Larvae reared with a mixed diet, including Type G microcapsules and a small amount of rotifers (0.5 rotifer m~-'), showed in general normal development of gut epithelium. These larvae had good growth but survival was reduced to one-half of that obtained under routine rearing of larvae fed on rotifers alone.Type G microcapsules appear to represent an adequate departure point for the development of an inert diet able to support larval growth in marine fish.

The effect of proteinase inhibitors in food protein hydrolysis by digestive proteinases of white shrimp (Penaeus vannamei) larvae

“…Ali 24 reported that juvenile Penaeus indicus, fed on ovalbumin feeds, discarded higher amounts of faecal nitrogen. Similar results were reported in larvae of the marine fish, Sparus aurata, fed with ovalbumin-based feed that inhibited the digestive proteinases, 25 and yielded lower growth and survival of the larvae. 26 The kinetics of inhibition of shrimp proteinases using MC 1 and MC 2 was obtained and results shown in Fig.…”

Suplementação de enzimas exógenas em dieta microparticulada para larvicultura do pacu

“…A presença de maior quantidade de reserva no fígado e vacuolização do intestino, mesmo após a transição alimentar aos cinco dias, sugere que, mesmo com uma ligeira redução no peso, as larvas do tratamento AV5DMP podem ter recebido maior aporte de nutrientes, como resultado dos efeitos da suplementação enzimática. A presença de vacúolos nos enterócitos e nos hepatócitos caracteriza a ocorrência de absorção de nutrientes (Yúfera et al, 1996), que refletiu nos resultados de crescimento, visto que as larvas do tratamento AV5DMP apresentaram peso maior (Tabela 2) que o das alimentadas com a dieta sem enzimas exógenas.…”

A review of the culture potential of Solea solea and S. senegalensis

“…Changes in energy content during larval development in J mg )1 dry matter (s) and J mg )1 ash-free dry matter(h) (FF first feeding; M start of metamorphosis) (from Yu´fera et al, 1999). (Yu´fera et al, 1996;Ferna´ndez-Dı´az and Yu´fera, 1997), may contribute to improve reproducibility of weaning success of S. senegalensis on an industrial scale. Furthermore, the molecular form of the dietary amino acids, in particular the relative proportion in which different types of free amino acids (FAA), small peptides and proteins are present in the diet, may be important for growth.…”