TO WHAT EXTENT DOES TEMPERATURE AFFECT SEX RATIO IN RED CHERRY SHRIMP, NEOCARIDINA DAVIDI? THE SCENARIO GLOBAL WARMING TO OFFSPRING SEX RATIO

An invasive freshwater shrimp, Red Cherry Shrimp (Decapoda: Caridea: Atyidae), is naturally distributed in fresh water habitats of Asia. This forage species has an important role in aquatic ecosystems by transferring planktonic production into higher trophic levels mainly including fish and aquatic animals. However, temperature strongly affects sex ratio and in turn offspring quantity. In order to determine the effect of temperature on incubation period, egg yield, offspring sex ratio as well as survival, a comprehensive experiment was conducted at three temperatures (20, 23 and 26ºC). Significant differences among temperatures for hatching period were an expected result. Higher survival and more eggs were achieved at 26ºC comparing the lower experimental temperatures. The female/male ratio, which was 80% at 20°C and approximately 50% at 23ºC, drastically dropped to 18% at 26°C. This ratio may drop to 0% at higher temperatures, which are tolerance limits for Red Cherry Shrimp. Therefore, in sex-dependent selective breeding, the temperature should be taken into consideration. Consequently, as temperature increases the sex ratio of the offspring increases in favour of the male. The continuation of global warming and rising above 26°C may be an important source of stress on the natural sustainability of Red Cherry Shrimp stocks.