Gonadal development and associated changes in gonadosomatic index and sex steroids during the reproductive cycle of cultured male and female Caspian brown trout, Salmo trutta caspius (Kessler, 1877)

Figures & data

Figure 1.  Cross section of ovary of Caspian brown trout (Salmo trutta caspius) at different stages of development. (a) Stage I: Chromatin nucleolus stage (in Out). (b) Stage II: Perinucleolus stage (in September). (c) Stage III: Oil droplet stage (in October). (d) Stage IV: Cortical alveoli stage (Early yolk globule stage) (in November). (e) Stage V: mid yolk globule stage (in December). (f) Stage VI: advanced mid yolk globule stage (in January). See text for description of stages. Sg, spermatogonia; Sc, spermatocyte; St, spermatid and Sz, spermatozoa. YG, yolk globule; N, nucleus’ CNe, chromatin nucleolus; Ne, nucleolus; O, oil droplets. HE ×40.

Figure 2.  Cross section of testes of Caspian brown trout (Salmo trutta caspius) at different stages of development. (a) Stage I: Spermatogonial proliferation (in Out), (b) (c) and (d) stage II: Mid spermatogenesis stage (during September to October), (e) stage III: Late spermatogenesis stage (in November); (f) stage IV: Prespermiation stage (in December). See text for description of stages. Sg, spermatogonia; Sc, spermatocyte; St, spermatid; Sz, spermatozoa. HE ×40.

Figure 3.  Milt quality parameters of male cultured Caspian brown trout. Spermatocrit (%), milt volume (mL), sperm density (×10 sperm/mL milt), percentage and duration (s) of sperm motility.

Figure 4.  Changes in GSI values of male and female cultured Caspian brown trout during the experimental period. Means with same superscripts are not significantly different (p>0.05).

Figure 5.  Changes in plasma T of male and female cultured Caspian brown trout during the experimental period. Means with same superscripts are not significantly different (p>0.05).

Figure 6.  Changes in plasma E₂ of male and female cultured Caspian brown trout during the experimental period. Means with same superscripts are not significantly different (p>0.05).

Figure 7.  Changes in plasma P of female cultured Caspian brown trout during the experimental period. Means with same superscripts are not significantly different (p>0.05).

Figure 8.  Changes in plasma Ca of female cultured Caspian brown trout during the experimental period. Means with same superscripts are not significantly different (p>0.05).

Figure 9.  Changes in plasma P of male cultured Caspian brown trout during the experimental period. Means with same superscripts are not significantly different (p>0.05).