Proboscis and foregut morphology of Ficus subintermedia (Ficidae, Caenogastropoda)
Contents
Abstract
Fig shells (Ficidae) have been identified as a putative sistergroup to Neogastropoda, although they have historically beenassociated with Tonnoidea. This study examines the morphol-ogy of the proboscis and foregut of Ficus subintermedia (d'Orbigny, 1852) and compares its major features to those ofNeogastropoda and Tonnoidea. The elongate ficid proboscis isoperated by an unusual arrangement of proboscis retractormuscles that connect to the esophagus and form a sheatharound the proboscis. It appears that the proboscis can not befully everted and is a functional analogue of an intraembolicproboscis, although this requires confirmation by observationof living animals. The salivary glands are shown to be superfi-cially bilobed but histologically uniform, and the esophagealgland is minimally septate and confluent with the esophagus.Despite a morphologically complex alimentary system, thereare few synapomorphies uniting Ficoidea with either Tonno-idea or Neogastropoda.
