Effects of salinity on the survival and histology of oysters Crassostrea gasar (Adanson, 1757)

Abstract

Water salinity is among the most important factors influencing the distribution, abundance, growth, and survival of Crassostrea gasar, an important aquaculture resource grown in estuarine environments in diverse regions of the world. The goal of the present work was to evaluate the effects of different salinities on survival and the tissues of C. gasar under laboratory conditions. Two experiments were performed using adult oysters from five marine farms located in the bay of Guaratuba, Brazil. In Experiment 1, the daily survival rates were evaluated after the oysters were submitted to gradual acclimatization at salinities ranging from 0 to 65 gL -1 and maintained in the laboratory without feeding for up to 365 days. In Experiment 2, the oysters were exposed to salinity from 0 to 50 gL -1 for up to 30 days without feeding and possible histological alterations caused by salinity were assessed. Three tolerance ranges of C. gasar to salinity were identified: "Optimal" (between 4 and 40 gL -1 ), "Tolerable" (between 2.1 and 3.9 and between 41 and 50 gL -1 ) and "Intolerable" (less than 2 and greater than 50 gL -1 ). No evidence of histological alterations was observed in oysters exposed to the different salinities.

Evaluation of methods for reducing epibionts during farming of the mangrove oyster Crassostrea gasar (Adanson, 1757)

“…In the present study, as C. gasar exhibited a high survival capacity of approximately 15 days in freshwater (Horodesky et al 2018), this has proved to be a safe and non-residual method for epibiont control. Hydroblasting and freshwater immersion were the most efficient methods of reducing the number of organisms in the Mollusca and Arthropoda phyla.…”

Growth and survival of the native oyster Crassostrea gasar cultured under different stocking densities in two grow-out systems in tropical climate

“…This effect was not observed for survivals rates in the adult phase. Crassostrea gasar is a euryhaline species that can survive in salinities between 4 and 40 for a long period (Horodesky et al, 2019). Differences in growth of C. gasar were also observed using floating system in two different marine and estuarine areas, in the South of Brazil (Legat et al, 2017).…”

“…Crassostrea gasar has specific characteristics that make it attractive for culture, such as resistance to varied temperatures and salinity (Horodesky et al, 2019), easy implementation (Sampaio et al, 2019), high market value and acceptance (Lameira-Silva et al, 2020). Studies on C. gasar oyster culture in estuarine waters have been developed to evaluate different stocking densities (Pereira et al, 2001), growth performance in different environments (Lopes et al, 2013;Legat et al, 2017;Oliveira et al, 2018) and yield of hatchery-produced seeds (Tureck et al, 2014).…”

Đánh giá tiềm năng probiotic của vi khuẩn phân lập từ hệ tiêu hóa của hàu Thái Bình Dương <i>Crassotrea Gigas</i> nuôi tại Ninh Hòa, Khánh Hòa, Việt Nam

“…Độ mặn của nước là một trong những yếu tố ảnh hưởng đến sự tăng trưởng của hàu TBD. Theo công bố của Horodesky và cộng sự (21), hàu TBD phát triển tối ưu ở độ mặn 0,4-4%, và không phát triển tốt khi độ mặn nhỏ hơn 0,2% và lớn hơn 5%. Do đó, trong thí nghiệm này, độ mặn 1, 2, 3 và 4 (%) đã được sử dụng làm thông số đánh giá khả năng chịu mặn của các chủng sàng lọc.…”