Sperm transfer in marine invertebrates: record of vermetid gastropod spermatophores in the plankton

The occurrence of Gastropoda Vermetidae spermatophores is recorded. They correspond to the spermatophores of the species Thylacodes arenarius (L., 1758) (= Serpulorbis arenarius (L., 1767) ). The morphological characteristics of the different spermatophores observed are showed and the records are analyzed in the light of the reproductive strategies of such aphallic sessile invertebrates.