논문 상세보기
Histological observation of gonadal differentiation in red spotted grouper (Epinephelus akaara)
- 언어ENG
- URLhttps://db.koreascholar.com/Article/Detail/355431
Red spotted grouper (Epinephelus akaara) is one of the most popular and important grouper species for aquaculture in South-East and East Asia thanks to its fast growth and high market value. This species is known as a protogynous hermaphrodite which first differentiates into females and changes to males later. Natural sex change in this species occurs at 2 or 3 years of age. Many studies have been conducted, so far, to develop standardized methods for artificial sex reversal by treatment with sex steroid hormones (Bhandari et al., 2005; Lee et al., 2014). However, sex-changed male groupers showed testes with ovarian cavity, and their sperm production was very low. Induction of primary sex differentiation directly into males would be an alternative approach. Identification of the exact primary sex differentiation period is the prerequisite for this approach.
Red spotted grouper were reared in indoor tanks and acclimatized at 25±2℃ under natural photoperiod. Fish were sampled at 60 days after hatching. The samples were processed for histological analysis using standard techniques in an automatic tissue processor, sectioned at 8 μm in thickness and stained with haematoxylin and eosin.
The result of this study shows the morphological characteristics of gonadal primordium, and suggests that the timing of gonadal differentiation in red spotted grouper is at least 10 days earlier than the previous study of Lee et al. (2014) which observed gonadal primordium at 70 days after hatching.
