Biochemical compounds’ dynamics during larval development of the carpet-shell clam Ruditapes decussatus (Linnaeus, 1758): effects of mono-specific diets and starvation

Abstract

Successful larval growth and development of bivalves depend on energy derived from internal (endotrophic phase) and external (exotrophic phase) sources. The present paper studies survival, growth and biochemical changes in the early developmental stages (from egg to pediveliger) of the clam Ruditapes decussatus in order to characterize the nutritional requirements and the transition from the endotrophic to the exotrophic phase. Three different feeding regimes were applied: starvation and two mono-specific microalgal diets (Isochrysis aff galbana and Chaetoceros calcitrans). A comparison between fed and unfed larvae highlighted the importance of egg lipid reserves, especially neutral lipids, during a brief endotrophic phase of embryonic development (first 2 days after fertilization). Egg reserves, however, may energetically contribute to the maintenance of larvae beyond the embryonic development. In fed larvae, the endotrophic phase is followed by a mixotrophic phase extending to days 5-8 after fertilization and a subsequent exotrophic phase. Metamorphosis starts around day 20. The intense embryonic activities are supported by energy derived from lipids, mainly from neutral lipids, and the metamorphic activities are supported by energy derived essentially from proteins accumulated during the planktonic phase and depend on the nutritional value of diets. The diet of I. aff galbana proves to be more adequate to R. decussatus larval rearing. The results provide useful information for the successful production of R. decussatus aquaculture.

Feeding selectivity of bivalve larvae on natural plankton assemblages in the Western English Channel

“…However, given that availability and quality of food may be patchy, both spatially and temporally, running a laboratory-based experiment on natural assemblages of bivalve larvae and prey may still not give a true representation of feeding in the field. Many studies suggest that bivalve larvae may have a high tolerance to food deprivation (Moran and Manahan 2004;Ben Kheder et al 2010;Matias et al 2011). However, food quality and quantity have a notable influence on the duration of larval phases (Ben Kheder et al 2010), and delayed development leaves larvae open to predation and therefore reduced recruitment.…”

“…Bivalve larvae may be released into the plankton to take advantage of a phytoplankton bloom (Pulfrich 1997;Highfield et al 2010); however, availability and quality of food may be patchy, both spatially and temporally (Haury et al 1978), thereby possibly creating a mismatch in the distribution of the bivalve larvae and their preferred diet. Despite studies suggesting that bivalve larvae have a high tolerance to food deprivation (Moran and Manahan 2004;Ben Kheder et al 2010;Matias et al 2011), food quality and quantity have a notable influence on the duration of larval phases (Ben Kheder et al 2010) with insufficient food resulting in delayed development. This meroplanktonic phase of bivalves is a critical period and if extended, the larvae may experience greater susceptibility to predation and environmental stresses.…”

Enhanced trace element concentrations in tissues of the clam <em>Ruditapes decussatus</em> transplanted to areas influenced by human activities (Ria Formosa, Portugal)

“…The production of R. decussatus is 47% of total aquaculture production in Portugal (DGRM 2013). The decline of clam production in the last two decades has been attributed to a combination of factors, such as clam mortalities probably related to pathologies and less favourable environmental conditions (Matias et al 2011). A field experiment was performed with the clam R. decussatus in inter-tidal ground plots.…”

Molluscs and echinoderms aquaculture: biological aspects, current status, technical progress and future perspectives for the most promising species in Italy

“…Much research has been carried out also on broodstock conditioning (Ojea et al, 2008;Matias et al, 2009) and on diets for Venerupis decussata larvae Matias et al, 2011) and seed (Albentosa et al, 1996a(Albentosa et al, , 1996b(Albentosa et al, , 1996c(Albentosa et al, , 1997Lamela et al, 1996;Jara-Jara et al, 1997;Fernández-Reiriz et al, 1998Pérez Camacho et al, 1998Enes and Borges, 2003) in controlled conditions. Furthermore, a number of successful trials have demonstrated the feasibility of rearing this bivalve in different European countries (Walne, 1976;Breber, 1985;Pastore et al, 1996) using different culture techniques in the sea as well as in coastal lagoons (Chessa et al, 1998(Chessa et al, , 2005Pais et al, 2006b;Serdar et al, 2007).…”