血清素对刺参繁育效果的影响

Effects of Serotonin on Reproductive Performance and Offspring Quality of Sea Cucumber,Apostichopus japonicus

本实验研究了在刺参(Apostichopus japonicus)人工促熟期间,向刺参体内注射血清素对刺参繁育效果的影响。在实验条件下,设置20、50、100和200μg/g亲参体重的4种血清素注射剂量,每种剂量又按每5、10、15和20d注射1次。以注射生理盐水的刺参为对照组,不做处理的刺参作为空白组。实验结束时,对亲参进行阴干流水升温刺激,诱导亲参排放精卵,检测雌参的繁殖力指标和子代质量指标。结果显示,所有注射血清素的实验组雌参排放率均高于注射生理盐水的对照组和未处理的空白组,其中,按50μg/g亲参体重的剂量每10 d注射1次,雌参排放率和平均产卵量最高,分别为(33.3±1.9)%和(637.0±111.1)万粒/头亲参,显著高于空白组和对照组。测定该组和空白组的子代质量指标,该组的卵子卵径、受精率、受精卵孵化率、9日龄幼体体长和幼体附着变态率分别为(165.0±3.5)μm、(93.0±1.5)%、(82.7±1.2)%、(856.0±24.8)μm和(24.0±1.9)%,与空白组之间无显著差异。研究表明,人工促熟期间向刺参体内注射血清素,可促进刺参性腺发育,提高繁育效果。

It is well-known that serotonin(5-hydroxytriptamine,5-HT)can act as a neurotransmitter as well as a neurohormone to regulate reproduction in marine invertebrates.Serotonin can prompt ovarian and embryonic development in crustaceans and trigger oocyte maturation and sequential spawning in bivalve mollusks.In this study,the effects of serotonin on the reproductive performance and quality of the offspring of sea cucumber(Apostichopus japonicus)treated with serotonin were examined.During hatchery broodstock conditioning,sea cucumbers were injected with serotonin at four different doses(20μg/g,50μg/g,100μg/g,and 200μg/g body weight)and four frequencies(every 5,10,15,and 20 days).Sea cucumbers injected with physiological saline were used as the control group,and untreated sea cucumbers were used as the blank group.At the end of the experiment,the spawning of sea cucumbers was triggered using a combination of desiccation,running water,and thermal shock.The results revealed that the spawning rate and fecundity of female sea cucumbers injected with serotonin were higher than those of the control and blank groups.The female sea cucumbers injected with serotonin at dose of 50μg/g body weight every 10 days showed the highest spawning rate and fecundity of(33.3±1.9)%and(637.0±111.1)×104 cells per individual,respectively.The egg diameter,fertilization rate of eggs,hatching rate of larvae,body length of late auricularia larvae,and settlement rate of larvae in the 50μg/g body weight every 10 days group and blank group were evaluated further.The egg diameter,fertilization rate,hatching rate,larval body length,and settlement rate of the 50μg/g body weight every 10 days group were(165.0±3.5)μm,(93.0±1.5)%,(82.7±1.2)%,(856.0±24.8)μm,and(24.0±1.9)%,respectively.No significant differences were observed in these parameters between this group and blank group.These results indicate that serotonin,as a neurotransmitter,prompts ovarian development in sea cucumbers,and injecting serotonin during broodstock conditions can improve the reproductive performance of female sea cucumbers.