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

Abstract

-The objective of this work was to evaluate the growth of the mangrove oyster Crassostrea gasar cultured in marine and estuarine environments. Oysters were cultured for 11 months in a longline system in two study sites -São Francisco do Sul and Florianópolis -, in the state of Santa Catarina, Southern Brazil. Water chlorophyll-α concentration, temperature, and salinity were measured weekly. The oysters were measured monthly (shell size and weight gain) to assess growth. At the end of the culture period, the average wet flesh weight, dry flesh weight, and shell weight were determined, as well as the distribution of oysters per size class. Six nonlinear models (logistic, exponential, Gompertz, Brody, Richards, and Von Bertalanffy) were adjusted to the oyster growth data set. Final mean shell sizes were higher in São Francisco do Sul than in Florianópolis. In addition, oysters cultured in São Francisco do Sul were more uniformly distributed in the four size classes than those cultured in Florianópolis. The highest average values of wet flesh weight and shell weight were observed in São Francisco do Sul, whereas dry flesh weight did not differ between the sites. The estuary environment is more promising for the cultivation of oysters.Index terms: mangrove oyster, mariculture, nonlinear models. Crescimento de Crassostrea gasar cultivada em ambientes marinho e estuarino em águas brasileirasResumo -O objetivo deste trabalho foi avaliar o crescimento da ostra-do-mangue Crassostrea gasar cultivada em ambiente marinho e estuarino. As ostras foram cultivadas por 11 meses em sistema de espinhel, em dois locais de estudo -São Francisco do Sul e Florianópolis -, em Santa Catarina. A concentração de clorofila-α, a temperatura e a salinidade da água foram registradas semanalmente. As ostras foram medidas mensalmente (tamanho da concha e ganho de peso) para avaliar o crescimento. No final do período de cultivo, os pesos médios de carne úmida, carne seca e concha foram determinados, bem como a distribuição das ostras por classes de tamanho. Seis modelos não lineares (logístico, exponencial, Gompertz, Brody, Richards e Von Bertalanffy) foram ajustados aos dados de crescimento das ostras. As médias finais de tamanho da concha foram maiores em São Francisco do Sul do que em Florianópolis. Além disso, as ostras cultivadas em São Francisco do Sul apresentaram distribuição mais uniforme nas classes de tamanho do que aquelas cultivadas em Florianópolis. Os maiores valores médios de peso de carne úmida e peso de concha foram observados em São Francisco do Sul, enquanto o peso da carne seca não diferiu entre os locais. O ambiente estuarino é mais promissor para o cultivo de ostras.Termos para indexação: ostra-do-mangue, maricultura, modelos não lineares.

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

“…Oysters from the present study showed a similar growth rate (5.8 mm and 6.6 g per month) compared to C. gasar oysters grown in shrimp ponds in the neighboring state of Rio Grande do Norte (5.2 mm per month) (DA SILVA et al, 2016). Moreover, the growth rate was better than oysters growing in shrimp ponds in the Sergipe state (2.37 mm per month) (ROSA, 2014) as well as in the marine and estuarine environments of South Brazil using spats produced in a hatchery facility (LOPES et al, 2013;PEREIRA et al, 2001). The latter authors reported oyster growth rates of 2.6 mm, 3.1 mm and 3.9 g per month.…”

“…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).…”

Epizootiology of Perkinsus sp. inCrassostrea gasar oysters in polyculture with shrimps in northeastern Brazil

“…However, some efforts have been made by research institutions to understand certain biological aspects of C. gasar that may be useful in the production process (LOPES et al, 2013;RAMOS et al, 2014;SILVEIRA et al, 2011;GOMES et al, 2014).…”

Parasites infecting the cultured oyster Crassostrea gasar (Adanson, 1757) in Northeast Brazil

“…In these ecosystems, the bivalves are used as food and a source of income for the local population. Such species are a promising economic alternative through a regular production system, as they grow fast (Lopes et al 2013) due to suitable temperatures (25-30°C) in the Northeastern region, in addition to the presence of an increasing consumer market.…”