Identifying the hormonal signature of gonad maturity and spawning seasonality is essential for upgrading the forecast of recruitment, environmental impacts, and captive maturation. The study evaluated the pattern of gonad development and associated plasma levels of sex steroids and thyroid hormones in both sexes to identify gonadal stage markers and reproductive seasonality in an Indian shad, Tenualosa ilisha. Various stages depicted the cellular organization of ovarian and testicular developments. The ovarian histology revealed hilsa as group synchronous total spawners. The seasonal distribution of distinct maturity stages indicated unsynchronized gonad development within the population. Hilsa exhibited a differential preference of environmental cues in spring and late autumn spawning. However, peak spawning activity took place at similar photoperiod and temperature. The appearance of post-ovulatory follicles (POFs) and late spermiating testicular lobules (LS) marked active spawning in different sexes. The gonadosomatic index (I_G) showed temporal, stage-specific variations with a positive correlation with plasma 11-KT (11-ketotestosterone), estradiol (E2) in females or with 17α, 20β-dihydroxy-4-pregnene-3-one (DHP) in males, although the relationship altered temporally for each variable. The positively correlated average plasma 11-KT and E2 values with the number of pre- and post-vitellogenic females serve as hormonal signatures for identifying initiation and completion of gonad growth, respectively. Higher circulating levels of 11-KT compared to T during annual gonad cycles indicate 11-KT as the predominant androgen that controls spermatogenesis in this species. Plasma DHP showed a minor peak in March and a significant elevation in October, synchronized with active spawning in females and males marked as a hormonal signature of spawning irrespective of sex. Plasma T4 showed a positive correlation with I_G and spawning females, whereas plasma T3 had a similar correlation with 11-KT and the number of early spermiating males in the population. The results demonstrate hormonal signatures of gonadal recrudescence, maturation, and spawning at the population level for promoting recruitment and artificial propagation of hilsa.

确定性腺成熟和产卵季节性的激素特征对于升级对招募、环境影响和圈养成熟的预测至关重要。该研究评估在两性性腺发育和性激素和甲状腺激素相关的血浆水平的模式，以确定在印度鲥鱼性腺阶段标记和繁殖季节性，Tenualosa鳓. 各个阶段描述了卵巢和睾丸发育的细胞组织。卵巢组织学显示 hilsa 是群同步总产卵细胞。不同成熟阶段的季节性分布表明种群内性腺发育不同步。Hilsa 在春季和深秋产卵时表现出对环境线索的不同偏好。然而，峰值产卵活动发生在相似的光周期和温度。排卵后卵泡 (POF) 和晚期精子生成睾丸小叶 (LS) 的出现标志着不同性别的产卵活跃。的性腺指数（I _ģ) 显示出与血浆 11-KT (11-酮睾酮)、雌二醇 (E2) 或男性的 17α, 20β-dihydroxy-4-pregnene-3-one (DHP) 呈正相关的时间、阶段特异性变化，尽管每个变量的关系在时间上发生了变化。正相关的平均血浆 11-KT 和 E2 值与产卵前和产卵后雌性的数量分别用作识别性腺生长开始和完成的激素特征。在年度性腺周期中，11-KT 的循环水平高于 T，表明 11-KT 是控制该物种精子发生的主要雄激素。血浆 DHP 在 3 月出现小峰值，在 10 月显着升高，与雌性和雄性的活跃产卵同步，标记为不分性别产卵的激素特征。_G和产卵雌性，而血浆 T3 与 11-KT 和种群中早期精子的雄性数量具有相似的相关性。结果证明了在种群水平上性腺复发、成熟和产卵的激素特征，以促进 hilsa 的招募和人工繁殖。