Paradiopatra hispanica Amoureux 1972

Paradiopatra hispanica (Amoureux, 1972)

Figures 9, 10, 12

Nothria hispanica Amoureux, 1972: 76, figs. 2, 3; 1974a: 136 (Portugal); 1974b: 114 (Bay of Biscay); 1982: 49; Campoy 1982: 554 –555.

Sarsonuphis hispanica.— Fauchald 1982: 74; Glémarec 1991: 549.

Paradiopatra hispanica.— Paxton 1986: 38; Aguirrezabalaga et al. 2002: 20 –23, fig. 2A–H (Capbreton Canyon); Paxton & Arias 2014: 898–899, fig. 5 (Bay of Biscay).

Material examined. Eight specimens (AM W45285), COCACE station G3 (43.88ºN – 06.11ºW), 571 m depth, 40.94% sand, 30.28% silt, 28.78% clay, Cantabrian Sea, Bay of Biscay, 0 3 Jul 1987; 5 specimens (MNCN 16.01/ 16630), COCACE station I6 (43.92°N – 6.11°W), 1186 m depth, 38% sand, 30% silt, 32% clay, Cantabrian Sea, Bay of Biscay, 0 4 Jul 1987; Several from the same locality for SEM studies; 1 specimen (AM W27376), Capbreton Canyon, 43º50.32’N – 02º10.94’W, 495 m depth, Cantabrian Sea, Bay of Biscay, coll. RV “Côte d’Aquitaine”, 10 Jul 1988; 3 specimens (MNCN 16.01/16631), N. Ribadesella (Asturias), 43º 49.76’- 43º49.89’ N –5º05.04’- 5º05.83’ W, 540-543 m depth, Cantabrian Sea, Bay of Biscay, coll. Fauna Ibérica II, 18 Jun 1991; 2 specimens (MNCN 16.01/16632), COCACE station H4 (43.77º N – 06.17º W), 790 m depth, 49.30% sand, 26.01% silt, 24.69% clay, Cantabrian Sea, Bay of Biscay, 25 Oct 1987; 3 specimens (MNCN 16.01/16633), COCACE station G1 (43.93º N – 5.66º W), 468 m depth, 67.54% sand, 16.64% silt, 15.82% clay, Cantabrian Sea, Bay of Biscay, 30 Jul 1987.

All specimens incomplete, lacking posterior ends; smallest specimen measuring 12 mm for 53 chaetigers, width 0.6 mm; largest specimen measuring 52 mm in length for 110 chaetigers, width 0.8 mm.

Diagnosis. Eyes absent; palps reaching chaetiger 1, lateral antennae reaching chaetiger 2–5 and median antenna chaetiger 1–3; ceratophores with 2–4 proximal rings and long distal ring, lacking lateral projections. Peristomial cirri present. Anterior three pairs of parapodia modified; ventral cirri subulate on first three to four chaetigers (Fig. 9), ventral glandular pads with a wide band consisting of two to three interrupted rows of cuticular pores (Figs. 12 C–E); subulate postchaetal lobes absent from chaetiger 9. Modified parapodia with pseudocompound bi- and tridentate falcigers with long pointed hoods; subacicular hooks starting from chaetigers 11–15; pectinate chaetae with 13–15 teeth, very sparse, present or absent in median and posterior parapodia, when present, never more than one per parapodium. Branchiae absent. Tube with inner parchment-like layer covered by thin, smooth muddy layer on distal part only, lower part only transparent secreted layer.

Variation. Paradiopatra hispanica displays a high degree of variability with respect to the number of anterior chaetigers with subulate ventral cirri and the first chaetiger with subacicular hooks; both characters are size-related (Fig. 10). The number of anterior chaetigers with subulate ventral cirri varies from two to four followed by one, two or three chaetigers with transitional ventral cirri shaped from subulate to round. Specimens of the smallest size had two ventral cirri followed by one to two chaetigers with transitional cirri (Fig. 9 B). Specimens larger than 0.4 mm had three chaetigers with subulate ventral cirri and specimens of the largest sizes (0.8–0.9 mm width) had three to four chaetigers with subulate ventral cirri, in the former followed by two chaetigers with transitional-shaped ventral cirri and with one in the latter (Fig. 9 A).

Remarks. This is a common species in the Bay of Biscay and Atlantic Iberian Peninsula and has been fully illustrated by Paxton & Arias (2014: Fig. 5).

Distribution. Atlantic Iberian Peninsula (Spain and Portugal), Bay of Biscay, English Channel SW of British Isles; at depths of 505-1113 m.