温度及盐度对卵形鲳鲹仔鱼存活和发育的影响

The effects of temperature and salinity on survival and development of larvae Trachinotus ovatus

摘要:

研究了不同温度、不同盐度对卵形鲳鲹(Trachinotus ovatus)初孵仔鱼存活和发育的影响。将卵形鲳鲹初孵仔鱼从温度24 ℃、盐度32的海水中分别转移至18 ℃、21 ℃、24 ℃、27 ℃中培育，每个温度各设6个盐度（16、20、24、28、32、36）。试验结果表明，环境变化1 d后，温度21 ℃、24 ℃、27 ℃与盐度16、20、24所组成的9个试验组存活率最低，均小于10%；盐度为28至36的仔鱼存活率较高,均大于50%；同时，在温度18 ℃环境下，不同盐度试验组的存活率均高于50%。温度对卵形鲳鲹仔鱼发育有显著影响，在一定范围内随着温度的降低，发育减缓。在18 ℃的环境下，仔鱼发育极为缓慢甚至停滞。结合仔鱼存活率和发育情况，其最适温度和盐度为孵化时的温度和盐度，即温度为24 ℃，盐度为32。

Abstract:

The aim of the present study was to investigate the effects of different temperatures and salinities on the survival and development of larva Trachinotus ovatus. The newly hatched larva was transferred from sea water (24 ℃, salinity 32) to and kept in a combination of four temperatures (18 ℃, 21 ℃, 24 ℃, 27 ℃) and six salinities (16, 20, 24, 28, 32, 36). After 1 day, the survival of larva Trachinotus ovatus exposed to combinations of salinities 16, 20, 24 and 21 ℃, 24 ℃, 27 ℃ are the lowest, less than 10%. The mortality of larva at salinities 28, 32, 36 were lower, less than 50%. Surprisingly, the survival rates of larvae at 18 ℃ with different salinities were higher, more than 50%. Our experiment showed that temperature plays a critical role in larva development.The larvae developed faster at higher temperature to a certain extent, the development of larvae Trachinotus ovatus became slow or even stopped at 18 ℃. Taking both survival and the development conditions into account, we draw a conclusion that the preferable temperature and salinity for larval survival and development is 24 ℃and 32, respectively.