Broodstock conditioning of the Portuguese oyster (Crassostrea angulata, Lamarck, 1819): influence of different diets

Abstract

The Portuguese oyster Crassostrea angulata shows great potential in oyster farming. The conservation of pure populations of this species is important for production diversification and biodiversity preservation. In this way, the zootechnological development for seed hatchery production is extremely important. Broodstock conditioning is a key step in the process of rearing bivalves in a hatchery. Many factors regulate the reproductive cycle, being food one of the most important ones. To evaluate the effect of different diets on C. angulata reproductive performance, broodstock were conditioned with different food regimes formulated fundamentally by flagellates (Diet 1 – Pavlova lutheri and Isochrysis galbana clone T‐ISO; Diet 2 – P. lutheri, T‐ISO and Skeletonema costatum) and constituted fundamentally by diatoms (Diet 3 – S. costatum and Chaetoceros calcitrans; Diet 4 – P. lutheri, S. costatum and C. calcitrans). During conditioning, samples of oysters were collected to evaluate condition index, gonadal development and biochemical composition. At the end of the conditioning period, oysters were induced to spawn to evaluate reproductive output (fecundity, fertilization rate and D‐larvae development). The diets had an impact on the gametogenesis process, energy storage and reproductive output performance, being the best results those obtained in broodstock fed with the diatoms‐predominant diets. However, those fed with diets majority flagellates had an unsuccessful performance. Holistic approaches incorporating all results in this study reveal and reinforce the idea that the diatom species used presented the nutritional requirements to C. angulata broodstock, being essential in the conditioning phase.

Elemental composition and bioaccessibility of farmed oysters (Crassostrea gigas) fed different ratios of dietary seaweed and microalgae during broodstock conditioning

“…There are several nutritional studies on bivalve species that have tested different algal compositions for an enhanced reproductive outcome (Anjos et al, 2017;González-Araya et al, 2012;González-Araya, Quéau, Quéré, Moal, & Robert, 2011;Pronker, Nevejan, Peene, Geijsen, & Sorgeloos, 2008;Utting & Millican, 1997). Currently, the most successful approach to a balanced diet lies in microalgal blends.…”

Fatty Acid Profile of Pacific Oyster, Crassostrea gigas, Fed Different Ratios of Dietary Seaweed and Microalgae during Broodstock Conditioning

“…Several nutritional studies in bivalves species (e.g., Anjos et al, ; González‐Araya et al, , ; Pronker et al, ; Utting and Millican, ) have focused in achieving an optimal algal composition that would lead to the best reproductive success. The dietary nutritional profile influences the physiology of bivalves, particularly the proteins, carbohydrates, and lipids (Joaquim et al, ; Matias et al, ).…”

“…The dietary nutritional profile influences the physiology of bivalves, particularly the proteins, carbohydrates, and lipids (Joaquim et al, ; Matias et al, ). Lipid reserves are of great importance for both energy source and gonadal development (Anjos et al, ), being used as energy source during gametogenesis (e.g., Delgado et al, ) and constitute the principal nutritional reserves in eggs and larvae (Helm et al, ; Matias et al, ). Furthermore, physiological relevance of lipids derives from the specific fatty acid (FA) profile.…”

Viability of dietary substitution of live microalgae with dry Ulva rigida in broodstock conditioning of Pacific oyster (Crassostrea gigas)

“…The success of bivalve production in hatcheries is undeniably related to the quality and the quantity of food available ( Delaporte et al, 2006 ; Helm et al, 2004 ). Energy reserves are of considerable importance in reproduction, and energy storage and utilization in bivalves are closely correlated to the quality of diet provided to adults, which consequently affects gonadal development, oocyte quality and larval viability ( Anjos et al, 2017 ; Utting and Millican, 1997 ).…”

“…Several nutritional studies in many bivalve species ( Anjos et al, 2017 ; González-Araya et al, 2011 ; González-Araya et al, 2012 ; Pronker et al, 2008 ; Utting and Millican, 1997 ) have focused in achieving the optimal algal composition to feed the broodstock, in order to accomplish optimum reproductive outcomes. The nutritional profile of the diet influences the physiology of bivalves, particularly the specific form of proteins, carbohydrates and especially lipids ( Joaquim et al, 2011 ; Matias et al, 2009 ).…”