A mouthless late‐term coach whipray Himantura uarnak embryo (Elasmobranchii, Dasyatidae) has implications for our understanding of matrotrophy in chondrichthyans

Abstract

AbstractMaternal nutrient provisioning occurs in most live‐bearing chondrichthyan lineages. It is particularly conspicuous in the Myliobatiformes, whereby the endometrium secretes a nutrient‐rich histotroph that is utilized by the developing embryo. The occurrence of a deformed and mouthless, late‐term myliobatiform embryo is described here, demonstrating that the direct, oral ingestion of histotroph is not obligatory in these animals.