Ellobiidae--Lost between land and sea

The Ellobiidae are a diverse group of archaeopulmonate snails living mostly near the sea. Their shell length ranges from barely 2 mm to over 100 mm. Six structural types of reproductive system set the boundaries for the subfamilial division: Pythiinae, Ellobiinae, Carychiinae, Cassidulinae, Pedipedinae, and Melampodinae. This division is in general supported by four structural types of nervous system and by the internal morphology of the penial complex. The halophile ellobiids are commonly associated with the supratidal fringe of mangroves and salt marshes; they are also important components of the supratidal biota of the mobile rocky shore. The various species occupy different portions of the shore. In rocky habitats, in addition to horizontal zonation, the ellobiids also partition their vertical distribution. The purpose of this study is to describe the zonation patterns of the halophile ellobiids of the cobble shores of the Acores and, in less detail, of the associated malacofauna.