Ovarian adaptations in the viviparous teleosts Clinus superciliosus and Clinus dorsalis (Perciformes: Clinidae)

Abstract

The anatomy and histology of the ovaries of C. superciliosus and C. dorsalis are described. The ovaries are extensively modified as trophic organs since embryos of both species develop intrafollicuiarly and are dependent on maternal nutrient secretions during development. The follicular epithelia of the two species are modified to perform a secretory function and follicular cells are hypertrophied in areas producing embryotrophe. In non-hypertrophied areas the follicular cells remain thin to bring about close contact between the embryos and the maternal vascular system underlying the epithelium. In C. superciliosus embryonic epidermal macroridges are closely aligned to areas of follicular hypertrophy thus forming a pseudoplacenta. A similar arrangement is not found in C. dorsalis.