Figure 6 in Seminiferous tubule number and surface: validation of objective parameters to estimate reproduction activity of male European anchovy (Engraulis encrasicolus, L.)

Figure 6. – Histological changes in testis development of Engraulis encrasicolus at the different reproductive maturity stages. A: Stage I, represented only by spermatogonia cells, inactive spermatogenesis, the number of the fields concerned in the biometric analysis N = 236. B: Stage II, active spermatogenesis with primary spermatogenium multiplication and tubular size increase, the number of the fields concerned in the biometric analysis N = 241. C: Stage III, active spermatogenesis, spermatozoa are concentrated in the light of the seminiferous tubules, the number of the fields concerned in the biometric analysis N = 125. D: Stage IV, spermiation, the number of the fields concerned in the biometric analysis N = 93. E: Stage V, seminiferous tubules are empty, spermatozoa are eliminated by release or resorption, the number of the fields concerned in the biometric analysis N = 988.