Several standard descriptions of the avian male and female reproductive tract have been reported, including effects of age, stage of reproductive maturity and gonadal hormone concentrations. Limited information on penguin reproductive biology and a lack of information on the African penguin (Spheniscus demersus) necessitated a detailed description of salient structural features of this species and provided an opportunity to evaluate seasonal changes in gonadal steroid hormone concentrations. Tissues from 36 males (adults and juveniles) and 29 females (adults and juveniles) were used for macro-anatomical descriptions and histology of the testes and ovaries. In addition, concentrations of gonadal steroid hormones for eight captive African penguins (four females and four males) were quantified during two breeding and one non-breeding season. The testes were asymmetrical, with the right testis having smaller dimensions compared to the left testis. Marked spermatogenic cellular associations and spermatid developmental stages were present in adult testes only during the breeding season. There was variation in the dimensions of the single ovary during follicular development related to the age and breeding status of the females. Testosterone, dihydrotestosterone, and estradiol concentrations fluctuated during the breeding and non-breeding periods, with males and females having similar steroid concentrations. The results from this study confirm that the breeding status in African penguins can be deduced based on testicular and ovarian histological structures. The results from the present study focused on African penguin reproductive biology should be considered in management strategies for the conservation of the species.

已经报道了几种对鸟类男性和女性生殖道的标准描述，包括年龄、生殖成熟阶段和性腺激素浓度的影响。关于企鹅生殖生物学的信息有限，缺乏关于非洲企鹅 ( Spheniscus demersus) 的信息) 需要对该物种的显着结构特征进行详细描述，并提供一个机会来评估性腺类固醇激素浓度的季节性变化。来自 36 名男性（成人和青少年）和 29 名女性（成人和青少年）的组织用于睾丸和卵巢的宏观解剖学描述和组织学。此外，在两个繁殖季节和一个非繁殖季节量化了八只圈养非洲企鹅（四只雌性和四只雄性）的性腺类固醇激素浓度。睾丸是不对称的，与左侧睾丸相比，右侧睾丸的尺寸较小。仅在繁殖季节，成年睾丸中存在显着的生精细胞关联和精子细胞发育阶段。卵泡发育过程中单个卵巢的尺寸存在变化，这与雌性的年龄和繁殖状态有关。睾酮、二氢睾酮和雌二醇浓度在繁殖和非繁殖期间波动，雄性和雌性类固醇浓度相似。这项研究的结果证实，可以根据睾丸和卵巢的组织结构推断非洲企鹅的繁殖状态。本研究的结果侧重于非洲企鹅生殖生物学，应在物种保护的管理策略中加以考虑。雄性和雌性具有相似的类固醇浓度。这项研究的结果证实，可以根据睾丸和卵巢的组织结构推断非洲企鹅的繁殖状态。本研究的结果侧重于非洲企鹅生殖生物学，应在物种保护的管理策略中加以考虑。雄性和雌性具有相似的类固醇浓度。这项研究的结果证实，可以根据睾丸和卵巢的组织结构推断非洲企鹅的繁殖状态。本研究的结果侧重于非洲企鹅生殖生物学，应在物种保护的管理策略中加以考虑。