温度、盐度对条石鲷胚胎发育影响及初孵仔鱼饥饿耐受力

Effects of temperature and salinity on embryonic developmentand starving tolerance of newly hatched larvae of rock bream Oplegnathus fasciatus

关键词:  条石鲷  胚胎发育  温度  盐度  饥饿

Key words:  Rock bream Oplegnathus fasciatus  Embryonic development  Temperature  Salinity  Starvation

摘要:

研究了盐度、温度对条石鲷胚胎发育的影响和初孵仔鱼对饥饿的耐受力。结果表明,胚胎发育的适宜盐度范围为20~35，最适盐度范围为25-30，孵化率都在89%以上，盐度低于20或高于35，孵化率都降低。盐度对孵化时间有一定影响，盐度高于35或者低于15条件下孵化时间都延长。胚胎发育的适宜温度范围为21-27℃，孵化率都在77%以上，最适温度范围为23-25℃，孵化率达89% 以上，低于19℃或者高于27℃时孵化率降低且初孵仔鱼畸形率升高。胚胎孵化时间与温度成负相关关系，胚胎发育速率与温度成正相关关系。条石鲷胚胎发育的生物学零度（阈温度）为10.06℃，有效积温值为405.3℃•h。对胚胎发育的Q10值进行了计算。饥饿条件下，条石鲷初孵仔鱼8日龄全部死亡，半数死亡时间出现在第6天，饥饿对初孵仔鱼生长具有明显的抑制作用。

Abstract:

A series of experiments have been conducted to study the effects of salinity and temperature on embryonic development and starvation endurance of newly hatched larvae of rock bream Oplegnathus fasciatus (T.& S.). Experiments were carried out in Qingdao Zhonghai Fishery Co., Ltd. from 2004~2007. Eggs were collected immediately after spawning and transferred into tanks for incubation. Salinity study was carried out in 2005, with treatmentsat salinities of 40，35，30，25，20，15，10 and 5.The results showed that the suitable salinities for embryonic hatching ranged from 20 to 35 with the most suitable range between 25～30, when hatching rates were all above 88%. Salinities above 40 or below 20 led to low hatching rate and prolonged hatching time. Temperature study was done in 2004,2005 and 2007, respectively. Taking into consideration the hatching rate,hatching time and deformity rate of the newly hatched larvae, it is deduced that the suitable temperatures for hatching ranged from 21～27℃ with hatching rates above 77%;most suitable temperatures were 23～25℃ with high hatching rates over 89% and low deformity rate of newly hatched larvae. Hatching time was negatively correlated with temperature while embryonic development speed was positively correlated with temperature. The threshold temperature for embryo development was calculated as 10.06℃, the effective accumulated temperature was 4053℃•h. In addition, Q10 value was calculated, and was found to accord with the experimental result. Newly hatched larvae were starved to death at 8 DAH with half death time appeared at 6 DAH;starvation had regative effects on larval growth.