Trophon geversianus (Pallas, 1774): the first record of communal egg masses in the muricid subfamily Trophoninae (Gastropoda)

Abstract

Reproductive strategies are thought to have played a major role inthe adaptive radiation of neogastropods, but data are still lackingfor important taxa, and the extent of plasticity in reproductivestrategies is not well understood. Females of the Patagonianneogastropod Trophon geversianus are here shown for the firsttime to have plastic egg capsule-laying strategies. Past work hasrecorded only egg laying by isolated females, both in the intertidaland in the lab. New observations of egg laying in subtidalT. geversianus show that communal oviposition also occurs in thisspecies, a first record of its kind for the species and for thesubfamily Trophoninae. Given that communal oviposition in otherspecies is commonly regarded as an adaptation to predation cuesor changing environment, we propose this reproductive strategyin trophonines is an inducible response to environmental risk.