THE MORPHOLOGY AND GONAD DEVELOPMENT OF PELTEOBAGRUS FULVIDRACO AND ITS INTERSPECIFIC HYBRID “HUANGYOU NO. 1” WITH PELTEOBAGGRUS VACHELLI

The yield of hybrid yellow catfish (Pelteobagrus fulvidraco♀×Pelteobaggrus vachelli♂) was gradually increased, but the basic research is rarely. In this study, a comparative analysis of morphology and gonad development of yellow catfish (Pelteobagrus fulvidraco) and hybrid yellow catfish " Huangyou No. 1” at 3 various ages was conducted. The hybrid yellow catfish has a growth advantage to yellow catfish. 22-month and 34-month-old yellow male catfish weight twice as much as females. However, sexual size dimorphism was greatly reduced in the hybrid yellow catfish. Completely degenerated ovarian with a fine line structure and no egg production were observed in female hybrid yellow catfish, indicating that the female hybrid yellow catfish is completely sterile. Testes of male hybrid yellow catfish were transparent and degenerated. The spermatogenic cyst was almost empty and had no sperm production in 10-month-old male hybrid yellow catfish, while a few sperms were observed in the spermatogenic cyst of 22-month- and 34-month-old male hybrid yellow catfish. Compared to yellow catfish, the number of sperms of hybrid yellow catfish were very small and their activities were low based on computer assisted spermatozoa analysis system (CASA). In addition, 22-month-old male hybrid yellow catfish has no reproductive capacity. The novel variety " Huangyou No. 1” has a hybrid advantage in growth performance and is expected to promote the development of yellow catfish industry.