Fig. 4.

Testis morphology of Fundulus (mean ± SEM). Immature spermatogenic cysts in control (A) and high dose BaP-treated (B) males, testis morphology of mature sperm in control (C) and high dose BaP-treated (D) males. The average cyst size (E) of immature SG = spermatogonia, SC = spermatocyte, ST = spermatid and percentage of immature cysts per phase (F) were not altered compared to control (t-test, p < 0.05, n = 4–5 tanks). High dose BaP treatment did not significantly affect the amount of mature spermatozoa in the seminiferous tubules (percentage fullness) (G). The percentages were calculated as (number of cysts within a stage/total cysts observed) × 100% and (area of spermatozoa/area of tubule) × 100% (n = 4–5 tanks /treatment group at 4 weeks).