Larval settlement and spat recovery rates of the oyster Crassostrea brasiliana (Lamarck, 1819) using different systems to induce metamorphosis

Abstract

This study aimed at the assessment, in the laboratory, of the larval settlement and spat recovery rates of oysters of the species Crassostrea brasiliana using plastic collectors, epinephrine (C9H13NO3 C4H6O6) and shell powder in settlement tanks. Polypropylene was used attached to bamboo frames. The material was chosen due to its pliability--that favours the spat detachment. Two experiments were carried out; the first between February and April 2008, and the second between November and December 2008 at the Marine Mussel Laboratory of Santa Catarina Federal University (Laboratório de Moluscos Marinhos da Universidade Federal de Santa Catarina). In the first experiment, the scratched plastic collectors were tested consorting them with shell powder; on the second, the plastic collectors were tested consorted with shell powder, only shell powder and epinephrine as the metamorphosis stimulator. The quantification was carried out of the larvae settled in the plastic collectors, and of the recovery and integrity of the spats after their detachment. The first experiment has shown a recovery rate of 48.83% of the spats in comparison with the D larvae used. From this percentage, 4.9% settled in the plastic collectors and 43.93% in shell powder. The second experiment revealed 55.78% regarding the settled spats in comparison with the total of larvae used (using epinephrine), 78.62% in the treatment with the collector plus shell powder and 58.33% in the treatment only with shell powder. Thus, the use of the collector plus shell powder resulted in a greater spat recovery when compared to the other treatments.

Growth of Crassostrea gasar cultured in marine and estuary environments in Brazilian waters

“…Ten percent of the broodstock was sacrificed and used to prepare solutions of both male and female gametes at unknown concentrations. The remaining broodstock was induced to spawn by temperature treatment and immersion regime according to the procedures described by Silveira et al (2011). Oysters were left in the tanks until the following day when the fecundity rate was evaluated.…”

“…Oysters were left in the tanks until the following day when the fecundity rate was evaluated. The resulting larvae were transferred to the culture tank, and larviculture was performed in January 2007, according to Silveira et al (2011).…”

Growth, mortality and susceptibility of oyster Crassostrea spp. to Perkinsus spp. infection during on growing in northeast Brazil

“…Recently, some studies were conducted in order to evaluate oyster maturation (RAMOS et al, 2014), larval settlement (SILVEIRA et al, 2011) and performance in culture (LOPES et al, 2013).…”

Survey of Pathologies inCrassostrea gasar(Adanson, 1757) Oysters from Cultured and Wild Populations in the São Francisco Estuary, Sergipe, Northeast Brazil

“…Currently in northeastern Brazil, the production of oysters is based exclusively on the collection of wild juvenile seed oysters that are then cultivated in grow-out bags. Because the culture of C. gigas is limited by excessive water temperatures in northeastern Brazil, there is an ongoing initiative to produce native oyster species on a large scale there to supply existing Brazilian markets, and new techniques are being developed to improve aquaculture of the native oyster C. gasar (Silveira et al 2011, Lopes et al 2013, Ramos et al 2013.…”