Halirages stappersi D'Acoz, 2012, sp. nov.

Halirages stappersi sp. nov.

Figs 10-12

Halirages elegans – Stappers 1911: 58-61, pl. 3 figs 5-18. — Stephensen 1931: 268-271, fig. 77; Stephensen 1938: 237, (key), 241. — Gurjanova 1946: 287 (discussion). — Yashnov 1948: 641, pl. 78 (after Stephensen 1931). — Gurjanova 1951: 605, 607-608, fig. 410 (after Stappers 1911).

Not Halirages elegans Norman, 1882: 688 (= H. qvadridentatus G.O. Sars, 1877).

Not Halirages elegans – Oldevig 1959: 65.

Etymology

Halirages stappersi sp. nov. is dedicated to the memory of Jean Hubert Louis Stappers (1883-1916), who collected the holotype of the species during the Arctic Campaign of 1907 of the Duc d'Orléans on the RV Belgica (see Barr 2010) and described it accurately, but under the name of Halirages elegans Norman, 1882. The name is a genitive.

Type material

RV Belgica, 1907, Kara Sea, stn 132, 71°03'N 057°48'E, 207 m: 1 ♂ holotype, 20 mm (pieces dissected out by Stappers not present), RBINS, I.G. 8749, INV. 101145.

Description

HEAD. (Fig. 10 A-B) Rostrum feeble; anterior lobe of head very bluntly subquadrate (almost rounded), posteriorly followed by narrow sinus; ventral lobe of head acute, pointing forward, not denticulate; eye large, subquadrate, with fully developed ommatidia, pigmentation retained after being stored in alcohol for a century.

ANTENNAE. (Fig. 10 A-C) Typical for the genus Halirages; article 1 of peduncle with 2 strong ventrolateral distal teeth.

LOWER LIP. (Fig. 10D) With narrow mandibular processes and broad outer lobes.

MANDIBLE. (Fig. 10E) Palp article 1 very short, with 2 D1-setae; article 2 and 3 equal in length; article 2 stout (2.9 x as long as wide), with row of D2-setae and subdistal row of A2-setae; article 3 falciform, with row of D3-setae on distal 0.8.

MAXILLA 1. (Fig. 10 F-G) Inner plate with 8 plumose setae, the length of which the size significantly increases towards tip; outer plate with 9 denticulate spines; palp well developed, with broad article 2; left article 2 with row of long styliform marginal spines and row of margino-facial setae; right article 2 with distal margin dentate, with 2 freely articulated anterodistal spines, with margino-facial row of welldeveloped setae.

GNATHOPOD 1. (Figs 10A, 11A) Coxa with anteroventral corner produced into a tooth pointing forwards, with 12-15 strong serrations along ventral margin; carpus 3.9 x as long as wide, almost as long as basis, anterior border without setae (except for distal tuft of seta); propodus 2.6 x as long as wide, 0.78 x as long as carpus; palm denticulate, with row of thin setae; palmar part of propodus 0.25 x as long as propodus; dactylus dentate.

GNATHOPOD 2. (Figs 10A, 11B) Coxa broadly rectangular, with about 13 distinct serrations along ventral margin; carpus 3.8 x as long as wide, distinctly shorter than basis, with anterior border setose; propodus 2.6 x as long as wide, 0.74 x as long as carpus; palm denticulate; palmar part of propodus about 0.22 x as long as propodus; dactylus dentate.

PEREIOPOD 3. (Fig. 11C) Coxa slightly longer than broad, with anterior and posterior border parallel, distally rounded, with ventral border serrate; leg distinctly spinose/setose; basis anteriorly weakly concave and posteriorly weakly convex; carpus 7.0 x as long as wide, 1.3 x as long as merus; propodus 8.0 x as long as wide, 1.5 x as long as merus; dactylus 0.39 x as long as propodus, 0.58 x as long as merus.

PEREIOPOD 4. (Fig. 10A) Coxa broad and serrate; leg missing but presumably similar to P3.

PEREIOPOD 5. (Fig. 11 D-E) Basis elliptic, with about 28 posterior and posterodistal distinct serrations (distal serrations irregularly shaped), with small but sharp anterodistal tooth; ischium with small but sharp anterodistal tooth; 3 distal articles missing.

PEREIOPOD 6. (Fig. 11F) Basis elliptic, with posterior and posterodistal distinct serrations (distal serrations irregularly shaped), with small but sharp anterodistal tooth; ischium with small but sharp anterodistal tooth; 4 distal articles missing.

PEREIOPOD 7. (Fig. 11 G-H) Leg distinctly spinose/setose; basis elliptic, 1.5 x as long as wide, anterior border setose, with small but sharp anterodistal tooth, posterior and posterodistal border with 29 serrations (distal serrations irregularly shaped); junction between posterior and posterodistal border bluntly angular; ischium with small but sharp anterodistal tooth; carpus 5.8 x as long as wide, 0.94 x as long as merus; propodus 13 x as long as wide, 1.2 x as long as merus; dactylus 7 x as long as wide, 0.36 x as long as propodus, 0.44 x as long as merus.

DORSAL ORNAMENTATION. (Fig. 12A) Pereionite 7 and pleonites 1-2 with strong posterodorsal tooth.

EPIMERA 1-2. Examination impossible without destructive dissection.

EPIMERON 3. (Fig. 12A) Without facial carina, with 9 strong isolate marginofacial spines and 4 marginofacial setules, with strong posteroventral tooth and strong posterolateral tooth, with posterior border between both teeth concave and serrate/crenulate.

UROSOMITE 1. (Fig. 12B) With 6 ventrolateral spines and 1 posteroventral spine.

UROPOD 1. (Fig. 12 B-C) Peduncle with 16-19 dorsolateral slender irregular-sized spines, with 16 dorsomedial slender irregular-sized spines; outer ramus about 0.7 x as long as inner ramus, with 9-11 dorsolateral irregular-sized spines, with at least 7 dorsomedial spines, with 4 apical spines; inner ramus as long as peduncle, with about 10 dorsolateral spines, with about 11 dorsomedial slender irregular-sized spines, with 4 apical spines; border of rami minutely serrate.

UROPOD 2. (Fig. 12B) Peduncle with 12 dorsolateral slender irregular-sized spines; outer ramus about 0.6 x as long as inner ramus.

UROPOD 3. (Fig. 12C) Peduncle with 6 distal dorsal spines, with dorsomedial border spinose; outer ramus with strong spines on lateral border, with medium-sized spines and plumose setae on medial border; inner ramus 1.4 x as long as peduncle, with medio-proximal bulging distinct, with 16 strong lateral spines, with 21 strong medial spines and 2 proximal plumose setae.

TELSON. (Fig. 12 E-F) Triangular, distally produced into a distal tooth flanked by 2 pairs of subdistal teeth, with a spinule in each interdental notch.

BODY LENGTH. 20 mm.

Variations

According to Stephensen (1931, as H. elegans), the posterodorsal tooth of pereionite 7 is sometimes lacking.

Distribution

Kara Sea, 207 m (Stappers 1911, as H. elegans); Svalbard, South of Jan Mayen, North of Faeroe Islands, Western Iceland, 700 to 1384- 1435 m, +0.4°C to +2.0°C (Stephensen 1931, 1938, as H. elegans); Northern Iceland, 407-996 m, -0.6°C to +0.1°C, i.e. in the Arctic Shallow Water Mass and the Arctic Bottom Water Mass (Weisshappel 2001, as H. elegans); Kara Sea, Laptev Sea, East Siberian Sea (Sirenko 2001). Brandt (1997) also records some 'cf. Halirages elegans ' from East Greenland between 260 and 2681 m, which possibly include specimens of the present species.

Remarks

Stappers (1911) provided excellent figures of many parts of the holotype and Stephensen (1931) gave further good drawings of the species, so that there is no need for a completely new set of figures, which would require further destructive dissections of the single type specimen. The illustrations of Stappers (1911) are simply reproduced herein, with a few complementary original figures made without dissection. It can be observed that the left rami of uropod 1, as illustrated by Stappers (1911) is shorter than the right rami examined during the present study. The right rami were somewhat distorted and this was possibly also the case of the left rami. So, it is possible that Stappers (1911) made an imperfect reconstruction of the appendage.