Sphaerephesia laureci ( 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 : 42-43

Sphaerephesia laureci ( Desbruyeres, 1980) comb. n. Figs 5J, K, 15C, D, 16

Sphaerodoropsis laureci Desbruyères, 1980: 219, pl. 5 A–C.

Type locality.

Meriadzek, Terrace, Bay of Biscay, 47°31'N, 9°35'W, 2325 m.

Material examined.

Holotype: MNHN TYPE 1286, Meriadzek, Terrace, Bay of Biscay, 47°31'N, 9°35'W, 2325 m.

Additional material.

(2 specs) Barents Sea: NTNU-VM 73789, (2 specs, one on SEM stub), Hopenbanken, 75°21.940'N, 26°37.120'E, 191 m, 29 Apr 2008.

Diagnosis.

Body cylindrical, with blunt anterior end, up to 4 mm long. Head appendages smooth, without spurs, median antenna shorter than other appendages. Antenniform papillae present. Dorsum with four longitudinal rows of macrotubercles in a single transverse row per segment, from segment 2. Macrotubercles sessile, spherical in anterior and pear-shaped in posterior segments. Additional small hemispherical papillae on dorsum, in four irregular transverse rows per segment, each segment with ca. 30 papillae. Ventrum with four slightly irregularly arranged transverse rows of papillae per segment, each segment with ca. 30-40 papillae. Parapodia digitiform from chaetiger 3, with ca. 12-14 rounded sub-equal papillae. Acicular lobe from segment 2. Ventral cirri digitiform surpassing acicular lobe tip. Compound chaetae with medium length blades (6-8 times as long as wide), showing slight gradation within fascicles.

Variation.

For this species only the holotype is known. However, some specimens from Norway are herein considered as potentially belonging to the same species. There are, however, some differences between the holotype and the Norwegian specimens. Norwegian specimens lack antenniform papillae (Fig. 16A, B). Dorsal papillae (additional to the macrotubercles) are arranged in four transverse rows per segment, each with 14-18 papillae on mid-body segments (near half of those in the original description, Fig. 15C). Ventral papillae also about half as many as in the holotype (Figs 15D, 16C). Interestingly, the parapodia bear ca. 16-18 rounded sub-equal papillae (Figs 5J, 16D, E) instead of the 14 reported in the original description. The acicular lobe is present from segment 1 (instead of 2). Ventral cirri are digitiform and do not surpass the acicular lobe tip (Fig. 16D, E). Otherwise, the general aspect, number and relative length of prostomial appendages and chaetal morphology, is similar between specimens examined.

Remarks.

Re-examination of the holotype resulted in a different interpretation of some morphological attributes with respect of the original description. We now state the prostomial appendages to be small and simple, instead of the bifurcated median antenna described originally. The dorsal macrotubercles are not invaginated and neither dorsoventrally flattened anymore in the preserved specimen. The number and arrangement of papillae is not clear from the original description. Approximately 12-14 spherical papillae randomly distributed over parapodial surface have been counted after re-examination (Fig. 5J).

Sphaerephesia laureci comb. n. is distinguished from other species in the genus by a unique combination of features: head appendages smooth, without papillae or spurs, dorsal macrotubercles spherical to pear-shaped, ca. 30 additional papillae, arranged in four irregular transverse rows both in dorsum and ventrum, 12-14 parapodial papillae and compound chaetae with blades up to eight times as long as wide.

Distribution.

Bay of Biscay and the western Barents Sea ( Desbruyères, 1980, present study).

Habitat.

No details were provided in the original description.