In the artificial breeding of Pampus argenteus (Euphrasen, 1788), female fish spawn before male release sperm, which indicates rapid ovarian development. In fish, aromatase is responsible for converting androgens into estrogens and estrogen plays a crucial role in ovarian development. In this study, we aimed to investigate the potential role of brain-type and ovarian-type aromatase to study the rapid ovarian development mechanism. The results showed that cyp19a1a was mainly expressed in the ovary and could be classified as the ovarian type, whereas cyp19a1b could be considered as the brain type for its expression was mainly in the brain. During ovarian development, the expression of cyp19a1a in the ovary significantly increased from stage IV to stage V and Cyp19a1a signals were present in the follicle cells, while cyp19a1b expression in the pituitary gland decreased from stage IV to stage V. To further investigate the function of Cyp19a1a, recombinant Cyp19a1a (rCyp19a1a) was produced and specific anti-Cyp19a1a antiserum was obtained. The expressions of cyp19a1a, estrogen receptors 2 alpha (esr2a), and androgen receptor alpha (arα) were significantly upregulated in the presence of rCyp19a1a. Meanwhile, cyp19a1a was expressed significantly after E2 treatment in both ovarian and testicular tissue culture. Taken together, we found two forms of aromatase in silver pomfret. The ovarian-type aromatase might play an important role in ovarian differentiation and maturation, and participate in E2 synthesis through co-regulation with esr2a. The brain-type aromatase cyp19a1b might be involved in the regulation of both brain and gonadal development.

In China, the silver pomfret (Pampus argenteus) is one of the most popular marine edible fish. To analyze the genetic characteristics of P. argenteus across three generations and evaluate whether continued progress can be made in body weight and growth traits, growth traits of the third-generation P. argenteus breeding and control groups were measured at 60, 90, and 120 days post-hatch. Using Pearson correlation and path analysis, we found a strong correlation between the growth characteristics of the third-generation P. argenteus and its body weight, with fork length and body length showing the strongest associations. Body weight, body length, and fork length all showed high levels of realized heritability at 120 days, with respective values of 0.55, 0.57, and 0.56. The genetic gain for body weight in the breeding groups over the three periods was 29.70 ± 0.58% (2.43 ± 1.17 g), which was significantly higher than the genetic gain for body length (8.90 ± 3.91%, 0.56 ± 0.29 cm) and fork length (8.08 ± 3.69%, 0.57 ± 0.33 cm). At harvest on day 120, the breeding group was 33.93% greater than the control group in terms of body weight. These results indicated that through mass selection, improvements were made to body weight of P. argenteus, leading to an enhancement in its growth performance. In the meantime, there was roughly equal genetic gain for body length, body weight, and fork length. These experiments showed that mass selection can effectively increase P. argenteus body weight, which will improve the species’ growth performance. These findings suggest that substantial genetic improvements can be achieved through mass selection for body weight, providing strong support for the ongoing P. argenteus selective breeding program.