Sphaerephesia longipapillata ( Desbruyeres , 1980) Desbruyeres, 1980

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 : 44-45

Sphaerephesia longipapillata ( Desbruyeres, 1980) comb. n. Figs 5L, 15E, F

Type locality.

Bay of Biscay, 47°31'N, 9°35'W, 4150 m.

Material examined.

Holotype: MNHN TYPE 1283, Bay of Biscay, 47°31'N, 9°35'W, 4150 m.

Diagnosis.

Body elongated, almost rounded in cross section, with blunt anterior end. Head appendages smooth, without spurs, median antenna shorter than other appendages. Antenniform papillae not conspicuous. Dorsum with four longitudinal rows macrotubercles in a single transverse row per segment, from segment 2. Macrotubercles large, sessile, spherical. Additional small spherical papillae on dorsum with unclear arrangement due to sediment covering epithelium. Ventrum with small hemispherical papillae. Parapodia digitiform from chaetiger 3, with 7-8 elongated papillae, larger papilla in dorso-distal position. Acicular lobe from segment 2. Ventral cirri digitiform surpassing acicular lobe tip. Approximately 20-25 compound chaetae with long blades (ca. 8-12 times as long as wide), showing slight gradation within fascicles.

Remarks.

The holotype has large, turgid, and almost spherical dorsal macrotubercles, but it is covered by a thin layer of sediment that makes the assessment of the number and arrangement of the small epithelial papillae over the dorsal and ventral body surface difficult (therefore Fig. 15E and F not necessarily accurate). A feature not highlighted in the original description is the number of chaetae, that can reach up to 30 in some mid-body fascicles, all with relatively long blades, measuring 8-12 times as long as wide. Sphaerephesia longipapillata comb. n. is distinguished from other congeners in the combination of three features: elongated and almost cylindrical body, presence of large (occupying most of the dorsum surface) and spherical macrotubercles, not pear-shaped (Fig. 15E) and chaetae with medium-long blades (ca.ten times longer than wide). The parapodia and parapodial papillae in the holotype are stretched, but it could be due to muscular relaxation of this particular specimen. The sigmoid acicula could not be verified in the opaque specimen. Two other NE Atlantic Sphaerephesia species with similar body shape and chaetae are S. philippi comb. n. and S. artabrensis comb. n., but both present pear-shaped macrotubercles in at least posterior chaetigers. Moreover, S. artabrensis comb. n. has less parapodial papillae (3-4 on each parapodium). Sphaerephesia longipapillata comb. n. was also characterised by the length of a dorso-distal parapodial papilla, a feature that could vary after fixation ( Helm and Capa 2015). However, the dorso-distal papilla is longer than the others in the material examined, and could be a distinct diagnostic feature together with the high number of chaetae per fascicle.

Distribution.

Only known from type locality.

Habitat.

No details were provided in the original description.