experiments on edible oyster spat collection at tutkorin

Relative toxicities were Hg > Cu > Zn at all temperatures, with significant differences (p < 0.0005)among all metals. With temperature, but within the narrow temperature range utilised the differences were only significant for zinc (p = 0.004). Results with individual metals revealed a tendency for 24 hour ECso's to increase Toxicity tests were performed to evaluate the isolated and two-way combined effects of the metals copper, mercury and zinc on the embryological development of the mangrove oyster, Crassostrea rhizophorae, at temperatures of 23, 26 and 29 ☌. The shellfish industrywill profit from the discovery of spatfields to developnewnursery practices that are eco-friendly and limit risks of transfers with other spatfall areas. This study provides new knowledge on the reproduction of the Pacific oyster in aMediterranean lagoon under warming and oligotrophication. gigas larvae, leading to poor recruitment. Under heterotrophic conditions, high abundances of mixotrophic and heterotrophic organisms (ciliates and dinoflagellates) limited the metamorphosis of C. In these favorable conditions, we hypothesize that the ecosystem functions as an autotrophic system, in contrast to the heterotrophic system that characterizes unfavorable conditions. We identified a favorable environmental window for recruitment characterized by high water temperature (>26.5☌) and high nanophytoplankton and Chaetoceros spp. Contrary to the 'no Pacific oyster reproduction' paradigm in Mediterranean lagoons, our study showed that recruitment of this introduced species is possible in the Thau lagoon at levels comparable to those in other traditional French breeding basins. Oyster spat and environmental parameters weremonitored at several sampling sites for 3 yr (2012 to 2014) using an original method with a temporal overlap deployment of collectors to study pre-and post-settlement processes and to identify the best conditions for recruitment. This is the case in Mediterranean lagoons, in particular the shellfish-farmed Thau lagoon in France, where we studied recruitment of the Pacific oyster Crassostrea gigas. In the context of increasing demand for environmental recovery, aquatic systemsmay face the challenge of evolving under oligotrophication.

This study site can also be used as a suitable location for the development of oyster culture in the cost of Bay of Bengal, Bangladesh based on its environmental characteristics.

The location in interaction with polluting materials such as total dissolved solids and total suspended solids had a significant effect on spat recruitment rate and therefore, Sonadia was the most suitable location for spat recruitment. Tiles were also found to facilitate with an advantage of recycling of this collector. Results also indicated spat recruitment was significantly influenced by the types of collectors and study locations with significantly (P < 0.05) higher spat were recruited in Tiles. However, these parameters were in suitable range for growth and spawning of oyster. Results indicated insignificant difference (P > 0.05) in temperature, salinity, dissolved oxygen and pH, while significant difference (P < 0.05) in total dissolved solids, total suspended solids and Chl-a content of the water among the study locations. On site sampling of water quality parameters and number of spats on each collector were done at 15-days interval following standard methods. Four types of collectors such as oyster shell, earthen pot, kortal (windowpane oyster shell) and tiles were investigated.

Standardizing the technique of spat collection is an important aspect in oyster farming.Potential spat collectors and suitable culture sites were investigated for the development of edible oyster culture from June to December 2019 at three study sites (Moheshkhali, the Jeti of Nuniarchora, and Sonadia) of Cox’s Bazar coast of Bangladesh.

Experiments on edible oyster spat collection at tutkorin