海南糙海参的繁殖生物学研究

Holothuria scabra is one of the southern tropical sea cucumber species, mainly distributing in Guangxi, Hainan Island Coasts and other region of Beibu Gulf.Due to overfishing and environmental deterioration, natural population resources of Holothuria scabra has greatly endangered in recent years. Little is known about reproductive biology of Holothuria scabra at home and abroad.At present we have achieved initial success in its artificial juvenile breeding, but the lack of understanding about reproductive biology characteristics of Holothuria scabra greatly restricted its breeding level and scale. For this purpose, a batch of wild sea cucumber Holothuria scabra will be connected and kept in fence net in its natural habitat sea area in Hainan, and sampled regularly in long term. By the methods of histology and electron microscope, several aspects on its reproductive biology including gonad development, important reproductive biological characteristics, spermatogenesis and oogenesis , individual fecundity and population reproductive ecology will be deeply studied in tissue, cell, individual and population level. After the completion of this project, we will obtain the systematic research achievements on reproductive biology of Holothuria scabra. This study will certainly play an important role in the improvements of artificial breeding level, the formation of Southern China coastal tropical sea cucumber industry and the restoration of natural populations of sea cucumber Holothuria scabra.

糙海参（Holothuria scabra）是一种具有南方特色的高档热带海参，主要产自广西、海南岛等北部湾海域，因过度捕捞和环境恶化其天然资源已处于濒危状态。国外关于糙海参繁殖生物学方面的研究资料极少，国内的相关研究亦属空白。目前糙海参的人工育苗已取得初步成功，但对天然糙海参繁殖生物学特性缺乏了解成为制约育苗水平的主要障碍。本项目在海南糙海参天然栖息区围网蓄养野生糙海参，定期采样，应用组织学方法和电镜手段在组织、细胞、个体和种群等不同水平上，针对糙海参在天然海域的性腺发育规律、重要的繁殖生物学特性、精子和卵子发生过程以及繁殖力和种群繁殖生态学等几方面内容展开深入研究。项目完成后，将获得天然糙海参上述繁殖生物学方面的系统研究成果。运用这些成果开展糙海参人工育苗，对于提高糙海参人工繁殖和育苗水平、形成华南沿海的热带海参养殖业以及今后恢复糙海参的天然种群资源都具有重要作用。

糙海参（Holothuria scabra）是产自广西、广东和海南岛等北部湾海域的热带海参经济种类，长期的过度捕捞和环境恶化已致其天然资源处于濒危状态。为了开展该物种的资源保护以及为人工繁殖生产提供参考，项目以海南糙海参为研究对象，以组织学切片、电镜技术以及常规采样为手段，针对糙海参的性腺发育规律、重要繁殖生物学特性、精子和卵子发生以及繁殖力和种群繁殖生态学等几方面内容展开研究。项目分析了来自783头野生糙海参的性腺组织学切片、电镜切片以及产卵和生态采样数据，结果发现：（1）海南糙海参雌雄的性腺发育均经历恢复期（Ⅰ期）、增长期（Ⅱ期）、成熟期（Ⅲ期）、部分排放期（Ⅳ期）、排空期（Ⅴ期）共5个时期。野生种群可能存在“性腺Ⅳ期恢复机理” 使其能全年持续繁殖。（2）海南糙海参精子发生经历精原细胞、初级精母细胞、次级精母细胞、精细胞和成熟精子5个阶段。个别精母细胞存在特殊的“连体发育现象”。精细胞分化分为早期、中期和晚期3个时期。成熟精子为典型的鞭毛型精子。（3）海南糙海参卵子发生共经历卵原细胞、卵黄发生前卵母细胞、卵黄发生期卵母细胞3个阶段。卵黄发生期卵母细胞分别包括卵黄发生早期、中期、后期3个阶段。（4）海南糙海参雌雄产卵和排精基本同步，产卵类型为分批产卵，全年产卵繁殖，有5～8月（夏季）和12～2月（冬季）两个繁殖盛期。初始性成熟年龄为2-3月龄，雌参的平均产卵量为123.61万/头。（5）海南新村港野生糙海参栖息海区共发现5种海草，海菖蒲（Enhalus acoroides）为绝对优势种，野生种群对海菖蒲和喜盐藻（Halophila ovalis）海草场存在明显选择偏好。项目获得了海南糙海参繁殖生物学的系统研究成果，应用上述成果，项目开发了糙海参种参人工培育促熟技术，优化完善了现有人工繁殖技术，提高了育苗技术水平；对今后开展华南沿海糙海参天然种群资源的保护与恢复亦具有实际指导作用。