Comparative morphology of the egg cases of Asymbolus analis, Asymbolus rubiginosus and Figaro boardmani (Carcharhiniformes: Scyliorhinidae) from southern Queensland, Australia

Descriptions of the egg cases of three catsharks, Asymbolus analis, Asymbolus rubiginosus and Figaro boardmani, are provided from 65 egg cases obtained from fishing surveys carried out on the continental shelf of southern Queensland, Australia. Egg cases of A. analis, A. rubiginosus and F. boardmani have the same basic morphology; they are typically vase-shaped, dorso-ventrally flattened and yellow and brown-tan in colour. The shape of the posterior border in terms of horn length and tendril thickness is the specific characteristic discriminating these three catsharks: enclosed horns in F. boardmani, short horns and tendrils in A. rubiginosus and long, coiled tendrils in A. analis. A non-parametric statistical approach was used as an exploratory tool for egg case identification in which six proportional measurements were sufficient to discriminate between species. Three egg cases of F. boardmani were recovered from the stomachs of three A. rubiginosus, which provided the first evidence of catshark-catshark predator-prey interaction.