Abstract:
Fatty acids and carotenoids are known to have roles in embryonic and larval development of sea cucumbers, but their changes in gonads during gametogenesis have not yet been studied. To improve our knowledge of the reproductive cycle of sea cucumbers in an aquaculture perspective, we collected 6-11 individuals of the species Holothuria (Panningothuria) forskali Delle Chiaje, 1823 approximately every 2 months from December 2019 to July 2021 east of the Glenan Islands (Brittany - France; 47.710°N, 3.948°W) at a depth of 8-12 m. Our results show that soon after spawning, sea cucumbers take advantage of an increased food availability in spring to rapidly and opportunistically accumulate nutrients in the form of lipids in their gonads (from May to July) and then slowly elongate, desaturate and probably rearrange fatty acids within lipid classes for the next reproductive season according to the specific requirements of both sexes. In contrast, acquisition of carotenoids occurs synchronously with gonads filling and/or through the reabsorption of spent tubules (T5), thus revealing little seasonal variations at the scale of the entire gonad in terms of relative abundance in both sexes. All results suggest that gonads are fully replenished with nutrients by October and that broodstock for induced reproduction could be captured at this moment and kept until the production of larvae is required. Maintaining broodstock for consecutive years would probably be a higher level challenge as the dynamics of tubule recruitment are not fully understood and seem to last for several years.
UNASSIGNED: The online version contains supplementary material available at 10.1007/s00227-023-04198-0.
摘要:
已知脂肪酸和类胡萝卜素在海参的胚胎和幼虫发育中起作用,但是它们在配子发生过程中性腺的变化尚未被研究。为了从水产养殖的角度提高我们对海参生殖周期的认识,我们收集了6-11个Holothuria(Panningothuria)物种forskaliDelleChiaje的个体,从2019年12月至2021年7月,大约每2个月在格莱南群岛以东(布列塔尼-法国;47.710°N,3.948°W),深度为8-12m。我们的结果表明,产卵后不久,海参利用春季增加的食物供应,以快速和机会性地在性腺中以脂质形式积累营养素(从5月到7月),然后慢慢拉长,根据男女的具体要求,在下一个生殖季节的脂质类别中去饱和并可能重排脂肪酸。相比之下,类胡萝卜素的获取与性腺填充同步发生和/或通过用过的小管的重吸收(T5),因此,就两性的相对丰度而言,整个性腺的规模几乎没有季节性变化。所有结果表明,到10月,性腺已完全补充了营养物质,并且此时可以捕获用于诱导繁殖的亲鱼,并一直保存到需要生产幼虫为止。由于尚未完全了解细管招募的动态,并且似乎持续了数年,因此连续多年维持育苗可能是一个更高层次的挑战。
■在线版本包含补充材料,可在10.1007/s00227-023-04198-0获得。