Scanning electron microscopy of intraovarian embryos of the viviparous teleost, Micrometrus minimus (Gibbons), (Perciformes: Embiotocidae)

Abstract

Scanning electron microscopy of the hypertrophied hindgut and spatulate expansions of the fin membrane in embryos of a viviparous surfperch Micrometrus minimus (Gibbons) has revealed evidence as to the role of these secondary embryonic adaptations in foetal‐maternal exchange processes. The villified hindgut probably functions primarily in the absorption of dissolved nutrient material from ingested ovarian fluid, while the vascular spatulate expansions facilitate the respiratory exchange of gases between embryonic and maternal circulations.