Cladistic relationships within Amphiglena Claparede (Polychaeta: Sabellidae) with a new species and a redescription of A-mediterranea (Leydig)

A new species of Amphiglena Claparede 1864, A. lindae n. sp., is described from Belize having up to five pairs of radioles, eight thoracic chaetigers, and as many as 26 abdominal chaetigers. This species, like other Amphiglena spp., is a simultaneous hermaphrodite with eggs and sperm developing in abdominal chaetigers. However, in A. lindae the gametes are found in the mid-abdominal region rather than the anterior abdomen. It is also unique in having a pair of spermathecae with red pigmentation at the base of the dorsal lips. A redescription of the type species of the genus, A. mediterranea Leydig, 1851, is also provided based on material from Italy. No type material of A. mediterranea was ever deposited but it is thought unnecessary to designate neotypes. The cladistic relationships among the species of Amphiglena are then assessed using an outgroup based on the six genera that are the sister group to the Laonome/Amphiglena clade. Two species of Laonome are included as part of the ingroup. The monophyly of Amphiglena is indicated by features previously identified by Fitzhugh (1989). A single most parsimonious cladogram for the various Amphiglena species was found with A. lindae as sister group to a clade comprised of A. pacifica and A. ter ebro. This clade was then sister group to a clade comprised of A. mediterranea and A. nathae.