Sphaerodoridium Luetzen , 1961

Capa, Maria, Nygren, Arne, Parapar, Julio, Bakken, Torkild, Meissner, Karin & Moreira, Juan, 2019, Systematic re-structure and new species of Sphaerodoridae (Annelida) after morphological revision and molecular phylogenetic analyses of the North East Atlantic fauna, ZooKeys 845, pp. 1-97 : 60-62

publication ID	https://dx.doi.org/10.3897/zookeys.845.32428
publication LSID	lsid:zoobank.org:pub:F05BDFEC-4C4A-4F22-9685-4AC2655B973D
persistent identifier	https://treatment.plazi.org/id/EA46B465-E911-083F-6D3B-48637D802CC9
treatment provided by	ZooKeys by Pensoft
scientific name	Sphaerodoridium Luetzen , 1961
status

Treatment

Sphaerodoridium Luetzen, 1961 View in CoL

Sphaerodoridium Lützen, 1961; Fauchald 1974: 270 (in part).

Sphaerodoropsis Hartman & Fauchald, 1971: 69 (in part); Fauchald 1974: 261 (in part); Borowski 1994: 23 (in part); Moreira 2012: 30 (in part); Capa et al. 2014: 17 (in part).

Type species.

Sphaerodorum claparedii Greeff, 1866.

Diagnosis.

Body short and ovoid, some forms slender. Prostomial appendages short, spherical or digitiform; median antenna shorter or as long as lateral antennae; antenniform papillae absent or present. Macrotubercles sessile or stalked; smooth, without terminal papilla, arranged in more or less clear longitudinal rows, one transverse row per segment, with at least seven macrotubercles each. Microtubercles absent. Additional papillae over body surface and parapodia. Parapodia with compound chaetae; stout hooks in anterior chaetigers absent.

Remarks.

In the present study, a clade was recovered containing species previously assembled under Sphaerodoropsis Group 2 ( Borowski 1994) (that is with sessile dorsal macrotubercles arranged in six or more longitudinal rows, and only one transverse row per segment), nested among other previously considered as Sphaerodoridium (that is with stalked macrotubercles) with more than seven longitudinal rows of macrotubercles (Fig. 1). This provides evidence that the macrotubercle morphology (i.e., sessile or stalked dorsal macrotubercles) is not a valid character separating reciprocally monophyletic groups. Instead, members of this clade should be considered as one genus containing sphaerodorids with more than six longitudinal rows of macrotubercles, arranged in a single transverse row per segment. Note that Borowski (1994) included one species bearing six macrotubercles in the first chaetiger under the artificial Group 2, like others in this group, but otherwise more than six. It is therefore here interpreted as belonging to the newly interpreted Sphaerodoridium : that is with more than six longitudinal rows of macrotubercles.

The type species of the genus Sphaerodoridium , S. claparedii , and the type species of Sphaerodoropsis , Sphaerodoropsis sphaerulifer share this feature. However, Sphaerodoridium was erected previous ( Lützen 1961) to Sphaerodoropsis ( Hartman and Fauchald 1971). Therefore, we consider this clade should bear the genus name Sphaerodoridium .

The diagnosis of the genus Sphaerodoridium differs from the original concept. In order to accommodate these, several systematic (all and only sphaerodorid species presenting seven or more longitudinal rows of macrotubercles, arranged in one transverse row per segment) are consider belonging to this group and nomenclatural changes are required.

Species currently considered within Sphaerodoridium are:

Sphaerodoridium aestuarum (Averincev, 1990), comb. n.

Type locality: Laptev Sea, 3-6.5 m.

Sphaerodoridium amoureuxi Aguirrezabalaga & Cebeiro, 2005

Type locality: Capbreton Canyon, Bay of Biscay, 984-1029 m.

Sphaerodoridium andamanense (Bakken, 2002), comb. n.

Type locality: Off Phi Phi Island, Andaman Sea, Thailand, 29 m.

Sphaerodoridium auranticum (Capa & Rouse, 2015), comb. n.

Type locality: Yonge Reef, Great Barrier Reef, Australia, 4-12 m.

Sphaerodoridium balticum (Reimers, 1933), comb. n.

Type locality: Kiel, Baltic Sea, 6-8 m.

Sphaerodoridium bengalorum (Fauchald, 1974), comb. n.