Characteristics of Gonadal Development of Pseudocrossocheilus bamaensis in Different Seasons
Analyzing the gonad development and tissue structure characteristics of Pseudocrossocheilus bam-aensis in different seasons can provide basic information for artificial breeding and germplasm resource pro-tection 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 conven-tional 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 nu-clear 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 translu-cent.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 sper-matocytes 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.
Pseudocrossocheilus bamaensisage of sexual maturitybreeding seasonfour seasons changere-production type