Euritmia Sarda-Borroy , 1987

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 : 24-25

Euritmia Sarda-Borroy, 1987

Euritmia Sardá-Borroy, 1987: 48; Moreira 2012: 41; Capa et al. 2014: 16; Capa et al. 2016a: 9.

Amacrodorum Kudenov, 1987: 917-918.

Type species.

Euritmia hamulisetosa Sardá-Borroy, 1987

Diagnosis.

Body short and ellipsoid. Head with short appendages, without spurs or basal papillae; antenniform papillae absent. Small tubercles or papillae spherical, sessile, smooth, without a terminal papilla, scattered over body surface and parapodia with apparent random distribution (over eight dorsal irregular longitudinal rows, and three or more transverse rows). Parapodia with short, rounded, ventral cirri, not surpassing the tip of acicular lobe. Stout hooks in anterior chaetigers absent. All chaetae simple unidentate, enlarged subdistally, with serrated edge.

Remarks.

The genus Euritmia was erected to gather sphaerodorids with tubercles scattered over the dorsum and simple chaetae, differing in morphology from chaetae present in other sphaerodorids ( Sardá-Borroy 1987, Capa et al. 2014) (i.e., Sphaerodorum and Commensodorum ). The lack of morphological differences across members of Euritmia and Amacrodorum , a genus erected in the same year ( Kudenov 1987) concluded in the recent synonimization of Amacrodorum ( Capa et al. 2016b). The presence of the characteristic simple chaetae is also shared by species of Sphaerodoropsis species belonging to the informal Group 4, sensu Borowski (1994), whose dorsal tubercles are also small compared to other sphaerodorids, but similar to those present in Euritmia , and arranged in several transverse rows per segment. No sequences of members of Euritmia or this group of Sphaerodoropsis have been produced to date to assess their relationships and position within the sphaerodorid tree, but it will be most interesting to test if these two groups ( Euritmia and Sphaerodoropsis Group 4) are closely related. Members of this group of Sphaerodoropsis are not reported in the NEA, or found in the present study.

The species currently considered in the genus are:

Euritmia bipapillata (Kudenov, 1987)

Type locality: Akutan Island, Alaska, 59 m.

Euritmia capense (Day, 1963)

Type locality: Cape Town, South Africa, unknown depth.

Euritmia carolensis Capa, Osborn & Bakken, 2016.

Type locality: Off South Carolina, USA, 799 m.

Euritmia hamulisetosa Sardá-Borroy, 1987.

Type locality: Cádiz, Spain, 0.5-10 m.

Euritmia nordica sp. n.

Type locality: Greenland, Denmark Strait, 321 m.