A Deep Insight of Spermatogenesis and Hormone Levels of Aqua-Cultured Turbot (Scophthalmus maximus)

Turbot ( Scophthalmus maximus ) is an important marine fish both in Europe and North China. Although there are plenty of studies on the reproduction turbot, complete cytological process spermatogenesis remains unclear. In this study, we investigated submicroscopic structure total 23 types male germ cells throughout breeding season, with a relatively primary spermatocytes. We found that spermatid tail formed early at Spermatid II, were least 16 spherical mitochondria spermatozoa. The hepatosomatic index (HSI) gonadosomatic (GSI) peaked during season. Preliminary analysis showed vitality mature sperm was negatively correlated proportion deformity. serum 3,5,3′-triiodothyronine (T3), 5-hydroxytryptamine (5-HT), testosterone (T), 17α,20β-Dihydroxy-4-pregnen-3-one (17α,20β-DHP), 17β-estradiol (E2) all increased maturity period, change T content most noticeable. Whereas testis, overall high level 11-ketotestosterone (11-KT) more remarkable. expression localization androgen receptor AR mRNA highly expressed stages II (15 – 70 g), slight rebound [IV(2200 g) to V(2500 g)], whose ahead changes 11-KT. Fluorescence situ hybridization (FISH) mainly distributed but not limited Sertoli cells. This study represents overview reproductive cycle which provides reference for research guidance flatfish breeding.