Haplocope diapira Błażewicz-Paszkowycz, Bamber & Cunha, 2011, sp. nov.
Creators: name: Błażewicz-Paszkowycz, Magdalena
name: Bamber, Roger N
name: Cunha, Marina R
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Tanaidacea
Colletteidae
Haplocope
Haplocope diapira

description: Haplocope diapira sp. nov.
Figs 4–6
Type material. 1Ƥ, Holotype (BMNH.2010.297), 2ƤƤ paratypes (BMNH.2010.298-299), Station Mer 576, Mercator mud-volcano, 35º17.657’N 06º39.129’W, 428 m depth, mud, Boxcorer, 26.07.2005, coll. MRC.
Other records. 6ƤƤ, same data as holotype; 1 specimen, Mer 569, Mercator mud-volcano, 35º17.917’N 06º38.717’W, 358 m depth, mud breccia, TV-grab, 25.07.2005, coll. MRC.
Description of female: body (Fig. 4 A, B) attenuate, holotype 1.6 mm long, 10 times as long as wide. Cephalothorax trapezoidal, 1.4 times as long as wide, 1.7 times as long as pereonite 1, narrowing towards anterior, naked, small rostrum present, eyes and eyelobes absent. Pereonites mostly longer than wide, naked; pereonite 1 wider than long; pereonites 2 and 3 subequal in length, 1.5 times as long as pereonite 1, 1.25 times as long as wide; pereonite 4 longest, 1.75 times as long as pereonite 1, 1.8 times as long as wide; pereonite 5 just shorter than pereonite 4, 1.9 times as long as wide; pereonite 6 as long as pereonite 1, 1.5 times as long as wide. Pleonites without pleopods, each pleonite 3.6 times as wide as long, pleonite 5 with single midlateral seta. Pleotelson (Fig. 6 G) pentagonal with triangular distal extension, as long as first three pleonites together, 0.8 times as long as anterior width, with paired distal setae.
Antennule (Fig. 5 A) just longer than cephalothorax, proximal article 2.3 times as long as wide, shorter than distal three articles together, subdistally with single simple seta and one penicillate seta; second article 1.5 times as long as wide, 0.4 times as long as first article, with one simple and two penicillate outer subdistal setae; third article twice as long as wide, 0.8 times as long as second article, with single simple and two penicillate distal setae; fourth article 1.7 times as long as third article, six times as long as wide, distally with five simple setae, one penicillate seta and one aesthetasc.
Antenna (Fig. 5 B) of six articles, proximal three articles compact, second article as long as wide, second and third articles with stout dorsodistal seta; fourth article longest, longer than first three articles together, distally with two simple setae and two penicillate setae; fifth article one-third as long as fourth, with single distal seta; sixth article shortest, one third as long as fifth, with five distal setae.
Labrum (Fig. 5 C) hood-like. Right mandible (Fig. 5 D) without lacinia mobilis, pars incisiva robust, pars molaris stout, with four broad distal teeth; left mandible (not figured) as right but with linguiform lacinia mobilis. Labium (Fig. 5 F) bilobed, outer-distal corner setulose. Maxillule (Fig. 5 E) endite with eight distal spines, palp not recovered; maxilla (Fig. 5 E) linguiform, naked. Maxilliped (Fig. 5 G) palp first article naked, second article with one outer and three inner setae one of which is bilaterally setulose; third article with two setulose longer and two simple shorter inner setae; fourth article with two inner, one outer and one stout distal setae; basis naked; endites distally with fine seta towards inner corner. Epignath (Fig. 5 H) slender, distally pointed.
Cheliped (Fig. 5 I) with rounded, naked basis, 1.5 times as long as wide; merus subtriangular, with single ventral seta longer than merus length; carpus 1.6 times as long as wide, with two long midventral one, short dorsodistal and one shorter dorsoproximal setae; propodus as long as carpus width, 1.25 times as long as wide, with seta at axis of fingers, fixed finger with two ventral setae, three setae on crenulate cutting edge; dactylus stout, naked.
Pereopod 1 (Fig. 6 A) coxa without seta; basis slender, 4.2 times as long as wide, with dorsoproximal penicillate seta; ischium compact, with single ventral seta; merus as long as carpus, and ventrodistally with single, slender, simple spine; carpus distally with single dorsal, mesial and ventral slender spines, dorsal spine twice as long as ventral spine; propodus almost twice as long as carpus, with ventral subdistal seta; dactylus naked; distinct, slender unguis twice as long as dactylus, both together 1.25 times as long as propodus. Pereopod 2 (Fig. 6 B) similar to pereopod 1, but coxa with seta, basis more slender, five times as long as wide, and propodus with ventral subdistal seta and dorsodistal seta. Pereopod 3 (Fig. 6 C) as pereopod 2.
Pereopod 4 (Fig. 6 D) more robust than anterior pereopods, basis 2.3 times as long as wide; ischium with two ventral setae; merus just shorter than carpus, and with two ventrodistal spines; carpus distally with inner and outer dorsodistal spines and paired ventrodistal spines; propodus just longer than carpus, with two ventrodistal and one dorsodistal spines and dorsodistal seta; dactylus 1.5 times as long as unguis, both together as long as propodus. Pereopod 5 (Fig. 6 E) as pereopod 4, but basis with midventral penicillate seta, carpus with additional dorsodistal seta. Pereopod 6 (Fig. 6 F) as pereopod 4, but propodus with two dorsodistal setae.
Pleopods absent.
Uropod (Fig. 6 G) biramous, long, slender, basis naked; exopod of two subequal segments, proximal segment with one distal seta, distal segment with two subequal setae; endopod of two attenuate segments, proximal segment shorter than distal segment, shorter than exopod, with one distal seta; distal segment distally with four simple and one penicillate setae.
Male unknown.
Etymology. from diapir – a mud-volcano-intrusion (after the Greek diapeirein, to pierce through), feminized to match the genus.
Remarks. The genus Haplocope (haplo – simple, cope – oar) was originated by Sars (1882) for what he considered his leptognathiid species – Haplocope angusta – with reduced pleopods in the female; the genus is otherwise characterized by a two-segmented uropod exopod, a rounded-denticulate mandibular molar, and a maxillule with eight distal spines. Subsequent species were attributed to this genus, but revised by other authors generally into Leptognathia Sars, 1882.
The three previously described species currently recognized in Haplocope are all from the North Atlantic: H. angusta, from the northern Northeast Atlantic at 22 to 275 m depth (see Holdich & Bird 1986), H. abyssorum Dollfus, 1897, from off the Azores at 1287 m depth, and H. linearis Hansen, 1913, from the Davis Strait at 1065 m depth and the Porcupine, Celtic and Hebridean Slopes at depths between 1271 and 1632 m (see Bird 2001). The generic attribution of H. oculatus Stebbing, 1918, an eyed species from the littoral of Natal, is at present speculative, apparently based on a juvenile specimen.
Haplocope angusta has reduced naked uniramous pleopods in the female, H. abyssorum has pleopods represented by quadrangular bases but no rami, and H. linearis has uniramous pleopods bearing long distal setae. In the present species the pleopods are absent.
In further comparison with the previous three species, Haplocope diapira sp. nov. has conspicuously moreelongate pereonites (6th pereonite longer than wide, wider than long in all of the others), and a uropod exopod longer than the endopod proximal article (shorter or of equal length in H. linearis and H. angusta) but shorter than the whole endopod (as long as the whole endopod in H. abyssorum). In addition, H. angusta and H. linearis have a distinctly more elongate second antenna article.
None of the other species are known to have been associated with sea-bed vents or seeps.
Haplocope diapira was collected from the Mercator mud-volcano in the El Arraiche field on the Moroccan margin, at depths from 358 to 428 m, on muddy-substrata.
description: Published as part of Błażewicz-Paszkowycz, Magdalena, Bamber, Roger N & Cunha, Marina R, 2011, New tanaidomorph Tanaidacea (Crustacea: Peracarida) from submarine mud-volcanoes in the Gulf of Cadiz (North-east Atlantic), pp. 1-53 in Zootaxa 2769 on pages 9-13, DOI: 10.5281/zenodo.204823