How is the morphology of the oviducal gland and of the resulting egg capsule associated with the egg laying habitats of Rajidae species

Egg capsules of Rajidae species vary in size, shape and adornments. These differences can be used as a taxonomic tool to differentiate species. Furthermore, since egg capsule external morphology is adapted to the environment where they are laid, it can be used make inferences on egg-laying grounds. In the present study, oviducal glands and egg capsules of seven species of skates (Leucoraja naevus, Raja brachyura, Raja montagui, Raja microocellata, Raja miraletus, Raja clavata and Raja undulata) are described and compared, and a taxonomic key developed. The resulting taxonomic key constitute a useful tool to identify skate species inhabiting Portuguese continental waters and, therefore, to improve our knowledge of egg laying habitatsproviding useful information for conservation and management.