This study was conducted to assess the physiological parameters of reproduction (sex ratio and gametogenic cycle), parasitism and biological indices (condition index and gonadal index) in Donax trunculus. Samples were collected monthly over two years (from 2016 to 2017) from three sites along the coast of Taghazout (in Southern Morocco) hosting the tourist resort Taghazout Bay. Five stages were depicted by histological examination of gonads: undifferentiated, developing, mature, spawning, and spent. The results of this histological study of the gonads of D. trunculus show that the reproductive cycle of this species has two periods: the first one is characterized by high sexual activity and extends from February to June and the second one corresponds to sexual rest and lasts from July to October. In all three stations and during both years, individuals in the undifferentiated stage (sexual rest) are encountered from July to October. Two spawning periods were observed: the first in March followed by a resumption of activity in April, and the second from May–June. Seasonal variations of the biological indices (GI and CI) were associated with the reproductive and nutritive status of bivalves. The study of parasitism by the trematode Bacciger Bacciger revealed that all the infected individuals were females in the sporocyst stage with a total prevalence between 0 and 9% in August and September respectively. Our results serve as a warning for future management measures and justify the necessity of taking into account the biology of the species in a particular area for better management of resources.

本研究旨在评估竹芋的生殖生理参数（性别比和配子周期）、寄生性和生物指数（状况指数和性腺指数）。在两年内（从 2016 年到 2017 年）每月从 Taghazout 海岸（摩洛哥南部）的三个地点收集样本，这些地点是旅游胜地 Taghazout 湾的所在地。性腺的组织学检查描述了五个阶段：未分化、发育、成熟、产卵和消耗。D. trunculus性腺的组织学研究结果表明该物种的生殖周期有两个时期：第一个时期的特点是性活动频繁，从 2 月持续到 6 月，第二个时期对应于性休息，从 7 月持续到 10 月。在所有三个站点和这两年中，在 7 月到 10 月期间都会遇到处于未分化阶段（性休息）的个体。观察到两个产卵期：第一个在 3 月，随后在 4 月恢复活动，第二个在 5-6 月。生物指数（GI 和 CI）的季节性变化与双壳类的繁殖和营养状况有关。吸虫Bacciger Bacciger寄生性研究揭示所有感染个体都是孢子囊阶段的女性，8 月和 9 月的总患病率分别在 0% 和 9% 之间。我们的结果可作为未来管理措施的警告，并证明有必要考虑特定地区物种的生物学以更好地管理资源。