Pseudobranchiomma Jones, 1962

Capa, Maria & Murray, Anna, 2016, Combined morphological and molecular data unveils relationships of Pseudobranchiomma (Sabellidae, Annelida) and reveals higher diversity of this intriguing group of fan worms in Australia, including potentially introduced species, ZooKeys 622, pp. 1-36 : 8

Taxon classification Animalia Sabellida Sabellidae

Pseudobranchiomma Jones, 1962

Pseudobranchiomma Jones, 1962: 198-201, figs 115-124; Fitzhugh 1989: 73; Nogueira and Knight-Jones 2002: 1661-1670; Knight-Jones and Giangrande 2003: 95-103; Nogueira et al. 2006: 588.

Type species.

Pseudobranchiomma emersoni Jones, 1962.

Diagnosis.

Radioles with or without radiolar flanges, serrated or smooth. Some species with paired compound eyes along radioles. Four rows of vacuolated cells supporting the radioles; a multicellular supporting axis of the radiolar appendages of the dorsal lips. Ventral sacs located outside the radiolar crown. Dorsal margins of collar separated from the faecal groove by a wide gap and without “pockets”. Segmental eyespots between the noto- and neuropodia. Spine-like chaetae arranged in oblique rows in the inferior thoracic fascicles. Thoracic companion chaetae absent. Well-developed conical abdominal neuropodia with chaetae arranged in C-shaped fascicles.

Remarks.

There is no apparent morphological synapomorphy supporting Pseudobranchiomma . The monophyly of the genus Pseudobranchiomma has not been tested prior to this study. The group has been defined by a combination of homoplastic characters: presence of radiolar flanges (shared with Stylomma and some Bispira species but absent in Pseudobranchiomma longa (Kinberg, 1867)); ventral sacs located outside the radiolar crown (shared with Bispira , Branchiomma and Sabella ); dorsal margins of the collar separated from the faecal groove by a wide gap and without “pockets” (shared by Bispira , Stylomma and some species of Branchiomma ); and absence of thoracic companion chaetae (shared with Branchiomma and Sabellastarte ) (e.g. Knight-Jones 1994, Nogueira and Knight-Jones 2002, Nogueira et al. 2006). It has been suggested that the colour pattern of the crown, consisting of transverse yellow and purple bands, could be another diagnostic feature for the genus ( Nogueira et al. 2006), but this feature is also very common in Sabellastarte species (e.g. Capa et al. 2010). The monophyly of Pseudobranchiomma is herein also questioned. Morphological data analysis recovers the group as paraphyletic, and the scarcity of molecular data gathered for the present study does not allow us to properly assess monophyly.