Vitamin requirements in great scallop larvae

Abstract

Vitamins were analysed in food (microalgae) and larvae of great scallop, Pecten maximus, during larval development. Microalgae used to feed larvae in hatcheries show great variability in their vitamin composition depending on both the species and culture condition (phase of growth). The microalgae used to feed Pecten maximus larvae were rich in vitamins; their content compared with diets used in fish culture appeared sufficient, with the possible exceptions of pyridoxine, biotin and pantothenic acid. Vitamins in bacteria, isolated from the larval rearing tank were also analysed, as they can also contribute to the diet. Vitamin B12, tz-tocopherol and t~-carotene were detected in very low concentration in bacteria; however, some bacterial strains were rich in pantothenic acid, and the pattern of other vitamins was similar to that from microalgae. The presence of bacteria can complement the diet in panthothenic acid, as it has been demonstrated that bacteria are ingested by larvae. The vitamin content of Pecten maximus larvae was analysed from the second day after hatching to just before metamorphosis. The content of some vitamins, ascorbic acid (C), ~x-tocopherol and l~-carotene, increased during larval development, suggesting that their requirement was satisfied. However, thiamin and riboflavin decreased during larval development and further studies, possibly using microencapsulated vitamins supplements, are needed to determine whether these vitamins are limiting during larval development.

Effect of a mono-specific algal diet on immune functions in two bivalve species -Crassostrea gigasandRuditapes philippinarum

“…Three algal mono-specific diets were selected from available strains in the hatchery according to their specific PUFA composition (Table·1). Although the vitamin and amino acid contents may vary between mariculture microalgae species, it is established that bivalve requirements for the above compounds are covered whatever the utilised species (Brown, 1991;Brown and Miller, 1992;Seguineau et al, 1996), Consequently, the PUFA composition was considered as the most determining factor of the nutritive quality of the dietary treatments, and the amino acid and vitamin compositions were considered as minor determining factors.…”

Effects of nutrition on larval growth and survival in bivalves

“…Individual amino acids were also not considered because Brown (1991) found that there were only minor variations in amino acid content among 16 species of algae commonly used in aquaculture and amino acids are less likely to be a factor than other nutrients. Vitamins were not included in this analysis because of a lack of research, although one study indicated that some vitamins may be limiting at various stages of larval development (Seguineau et al. 1996).…”

Bacteria as food in aquaculture: do they make a difference?

“…Bacteria isolated from P. maximus larval tanks contained very low concentrations of vitamin B12, α‐tocopherol and Β‐carotene but some bacterial strains were rich in pantothenic acid, and the level of other vitamins was similar to that of microalgae (Seguineau et al . ). Yu et al .…”