Department of Medical Bioscience, University of the Western Cape, Bellville, 7535, South Africa; National Zoological Garden, South African National Biodiversity Institute, Pretoria, 0001, South Africa.
National Zoological Garden, South African National Biodiversity Institute, Pretoria, 0001, South Africa; Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Hatfield, 0028, South Africa.
Anim Reprod Sci. 2021 Jan;224:106664. doi: 10.1016/j.anireprosci.2020.106664. Epub 2020 Nov 26.
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.
已经有几种关于禽类雄性和雌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。由于对企鹅生殖生物学的了解有限，且对非洲企鹅（Spheniscus demersus）的了解有限，因此需要详细描述该物种的显著结构特征，并提供评估性腺类固醇激素浓度季节性变化的机会。使用 36 只雄性（成年和幼年）和 29 只雌性（成年和幼年）的组织进行睾丸和卵巢的宏观解剖描述和组织学研究。此外，在两个繁殖季节和一个非繁殖季节期间，对 8 只圈养非洲企鹅（4 只雌性和 4 只雄性）的性腺类固醇激素浓度进行了定量分析。睾丸不对称，右侧睾丸的尺寸比左侧睾丸小。仅在繁殖季节，成年睾丸中存在明显的精子发生细胞关联和精子细胞发育阶段。在卵泡发育过程中，由于雌性的年龄和繁殖状态，单个卵巢的尺寸存在变化。在繁殖和非繁殖期间，睾酮、二氢睾酮和雌二醇浓度波动，雄性和雌性的类固醇浓度相似。本研究的结果证实，可以根据睾丸和卵巢的组织学结构来推断非洲企鹅的繁殖状态。本研究中重点关注的非洲企鹅生殖生物学的结果应在该物种保护的管理策略中考虑。
