These and other benthic predators, such as sea anemones, barnacles, and ascidians, feed on oyster larvae or oyster veliger, thus limiting oyster larval settlement. īarnacles feed on a wide variety of planktonic organisms ranging in size from flagellates to small crustaceans. Temperature and salinity affect barnacle spatfall similarly to oyster larvae. Barnacles are one of these sessile fouling organisms commonly found on oyster clusters and can cause problems for oyster culturists. In addition, oyster spatfall is influenced by competition between oyster larvae and larvae of other species, such as sessile or fouling organisms. Settlement or spatfall is a vital event in the life cycle of oysters, and temperature and salinity influence oyster spatfall. The Portuguese oyster has a wide distribution in subtropical Taiwan and southern China. Studies have shown that the two oysters also differ in their filtration rates, activity levels at low temperatures, and growth rates. The Pacific oyster is native to temperate waters close to Japan and Korea, whereas the Portuguese oyster is found in the waters surrounding Taiwan. The Pacific oyster and the Portuguese oyster Crassostrea angulata (Lamarck 1819) were considered a single species until recently when molecular biology studies proved otherwise. The Pacific oyster Crassostrea gigas (Thunberg 1793) is a well-known commercial oyster cultivated in many countries and areas, including the United Kingdom, Japan, Korea, Australia, and Taiwan. Oyster aquaculture is widely distributed in the world and provides high economic value. Although the oyster larvae are more abundant in spring, fishermen prefer harvesting the larvae in autumn to avoid the typhoon season (July-September).Ĭorrelation, Influence, Rainfall, Recruitment, Spat There are two main culturing seasons that move oyster larvae from coast of Taisi to farms in other places: from March to May and from August to September. angulata and barnacle settlement, the eigenvalue of PC1 was 1.83 and could explain 61.0%. Rainfall was the major factor that influenced oyster C. The primary of adherence spawning season of barnacles was from March to October. The primary spawning season was from March to September. The average adherence density of the barnacle larvae was 187.1 ± 251.2 individuals/shell (N = 60) at site A and 60.9 ± 112.5 individuals/shell (N = 37) at site B. The average recruitment density, measured once every two weeks, of the oyster larvae was 256.4 ± 236.6 individuals/shell (N = 62) at site A and 118.5 ± 140.2 individuals/shell (N = 39) at site B. This study investigated oyster cultures at two locations along the coast of Taisi Township from March 2012 to July 2014. The Portuguese oyster (Crassostrea angulata) is an important fishery resource in Taiwan. Received: FebruAccepted: MaPublished: March 20, 2020 This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). 1Department of Environmental Engineering, Kun-Shan University, Tainan, TaiwanĢDepartment of Ecology and Environmental Resource, National University of Tainan, Tainan, TaiwanģTainan Hydraulics Laboratory, National Cheng Kung University, Tainan, TaiwanĬopyright © 2020 by author(s) and Scientific Research Publishing Inc.
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