不同季节巴马拟缨鱼性腺发育特征

Characteristics of Gonadal Development of Pseudocrossocheilus bamaensis in Different Seasons

关键词:  巴马拟缨鱼  性成熟年龄  繁殖季节  四季变化  繁殖类型

Key words:  Pseudocrossocheilus bamaensis  age of sexual maturity  breeding season  four seasons change  reproduction type

摘要:

通过分析巴马拟缨鱼(Pseudocrossocheilus bamaensis)不同季节性腺发育及组织结构特征，为人工繁殖巴马拟缨鱼及种质资源保护提供基础资料。本研究采用常规解剖学和组织学方法，研究巴马拟缨鱼性腺组织结构、性腺发育分期和群体年龄结构的四季分布特点。结果显示，巴马拟缨鱼卵巢时相春季主要为Ⅲ期，卵黄泡数量增加，核仁数减少，核空泡消失，核膜不明显，卵粒呈浅黄色；夏季为Ⅲ期和Ⅳ期，卵黄泡数量明显增多，卵黄颗粒逐渐充满整个细胞，细胞体积更大，卵子颗粒分明，大小较一致；秋、冬季均为Ⅱ期，卵粒不能分离，呈极小半透明，卵母细胞间分布有结缔组织。巴马拟缨鱼精巢时相春、秋和冬季以Ⅱ期为主，半透明细线状的精巢紧贴于鳔腹面两侧，细胞核大且颜色较深，细胞质浅红色，且具有透明泡状；夏季为Ⅲ期和Ⅳ期，精巢体积增大，表面血管发达，呈淡红色，视野充满初级精母细胞和次级精母细胞。基于性腺发育期季节性变化特点推测，巴马拟缨鱼雌、雄鱼的繁殖季节均为夏季，产卵类型为同步产卵。

Abstract:

Analyzing the gonad development and tissue structure characteristics of Pseudocrossocheilus bamaensis in different seasons can provide basic information for artificial breeding and germplasm resource protection of P.bamaensis in the future.In this study,the distribution characteristics of gonad structure,stages of gonad development and population age structure in P.bamaensis in four seasons were studied by conventional anatomical and histological methods.The results showed that the ovarian phase of P.barmaensis was mainly stage Ⅲ in spring.The number of yolk vesicles increased.The number of nucleoli decreased.The nuclear vacuoles disappeared.The nuclear membrane was not obvious,and the egg was light yellow.In summer,it was stage Ⅲ and Ⅳ,the number of yolk vesicles increased significantly.The yolk granules gradually filled the whole cell.The cell volume was larger.The egg granules were distinct and the size was more consistent.In autumn and winter,the eggs were in stage Ⅱ.The eggs could not be separated and were extremely translucent.The connective tissue was distributed between the oocytes.The testis phase of P.baimanensis was mainly in stage Ⅱ in spring,autumn and winter.The semi-transparent fine linear testis was close to both sides of the ventral surface of the swim bladder.The nucleus was large and dark.The cytoplasm was light red,and had a transparent bubble shape.In summer,the testis were in stages Ⅲ and Ⅳ.The volume of testis increased.The surface blood vessels were developed and pink,and the field of vision was full of primary spermatocytes and secondary spermatocytes.Based on the seasonal variation characteristics of gonad development period,it is speculated that the breeding season of both female and male P.baimanensis is summer,and the spawning type is synchronous spawning.