Application of a bioenergetic growth model to larvae of the pearl oyster Pinctada margaritifera L.

Abstract

We applied, for the first time, a dynamic energy budget (DEB) growth model to the larval phase in the pearl oyster Pinctada margaritifera var. cumingii (Linné 1758) to evaluate the impact of spatio-temporal variation in the atoll lagoon environment on its capacity for development. The specific parameters of the model, which represent ingestion, temperature effect and the relationship between length and biovolume of the larvae, were determined from experiments or taken from the literature. The interpretation of the values of these parameters allowed us to identify the underlying adaptive character trait: P. margaritifera larvae have a good capacity to exploit low food concentrations and a narrow range of thermal tolerance restricted to hydrobiological conditions found in the tropical oligotrophic waters of its distribution zone. Growth simulations show a good fit with the observations made on reared larvae under different conditions, fed on either cultured algae or natural plankton, and with growth data from a natural cohort. Finally, a first application of the model to a pearlculture lagoon reveals the predominant effect of the vertical structure of trophic resources in determining spatial variation in larval growth. Research highlights ► We developed a DEB model for Pinctada margaritifera larvae. ► To our knowledge, it is the third application of a DEB model for bivalve larvae, but the first one for tropical bivalves. ► This model is used to give insight into the ecology of this species. ► Application for aquaculture purposes is also discussed.

Bivalve larvae transport and connectivity within the Ahe atoll lagoon (Tuamotu Archipelago), with application to pearl oyster aquaculture management

“…The lifespan of the larval stage, observed in hatcheries averages 21 days for P. margaritifera (Doroudi and Southgate, 2003). However, depending on environmental conditions (e.g., temperature, food concentration), lifespan may vary from 15 to more than 30 days (Thomas et al, 2011). At the end of their development, larvae reach 230 lm length on average.…”

Population Connectivity and Genetic Assessment of Exploited and Natural Populations of Pearl Oysters within a French Polynesian Atoll Lagoon

“…Spat collectors (18 in total) were placed in the lagoon in the second week of February 2017 in three geographic locations commonly used for collection by professionals (South West lagoon) and in three additional locations to cover the whole study area. Assuming a mean pelagic larval duration of 25 days [6,20,21], these collectors had the opportunity to collect any larvae spawned between approximately three weeks before their positioning and three weeks before their removal. Collectors were sampled at the end of May 2017 and spats of at least 3 mm were kept (to allow proper identification of the species).…”

“…margaritifera is a broadcast spawner that releases gametes in the water column, which upon fertilization will produce a D larva in the first 24 h post fertilization. The pelagic larval duration (PLD) of P. margaritifera was estimated around 21 to 25 days in hatchery conditions [20], though it could vary from 15 to 30 days in environmental conditions commonly found in French Polynesia (e.g., temperature, food concentration) [21]. Larvae usually disperse through drifting in the lagoon currents, though they have the capacity to do vertical migration in the water column [3].…”

“…Among the six sets of collectors deployed in the lagoon, the set #6 could not be located in May and was considered lost. From the five collectors left, we collected a total of 41 individuals (21,8,7,4 and 1 individual from C3, C5, C1, C4 and C2 respectively).…”

Estimation of physical and physiological performances of blacklip pearl oyster larvae in view of DEB modeling and recruitment assessment

“…Then, the so-called optimal window theory (Cury and Roy, 1989) linked spawning output and recruitment success through larval development and environmental conditions. This theory emphasized that "match-mismatch" between the presence of trophic resource and period of larval development can explain recruitment variations for bivalves species (Olson, 1989;Menge et al, 2009;Thomas et al, 2011). The lack of a quasi-deterministic relationship between spawning and recruitment continues to confound attempts to fully understand and predict population dynamics.…”