Gunnar thorson's world-wide collection of prosobranch egg capsules: Fasciolariidae

Abstract

This report summarizes what is known about spawning behavior, gross morphology of egg capsules, and the hatching stage of 37 fasciolariid species including representatives from Fasciolariinae, Fusininae, and Peristerniinae. New data and illustrations of spawns and/or individual egg capsules in several views are presented for 24 species, of which nine are entirely new descriptions. Intact spawns (masses of encapsulated, fertilized eggs or embryos) demonstrated that fasciolariid egg capsules typically are vasiform with distinct lateral sutures and a mucoid plug in an escape aperture. One fasciolariine, one fusinine, and three peristerniine species construct bulliform encapsulations. Fasciolariids do not produce complex capsular morphologies or arrangements of capsules that have obvious adaptive value. With the exception of the bullate species, egg capsules deposited by fasciolariines and fusinines have species-specific features on the apical ridge. Most conical peristerniine egg capsules without complex sculpture on the apical ridge cannot be considered species-specific, at least until the products of more species are described and the range of variation is known.