Haploniscus bihastatus, Brökeland, Wiebke, 2010

Brökeland, Wiebke, 2010, Description of four new species from the Haploniscus unicornis Menzies, 1956 complex (Isopoda: Asellota: Haploniscidae), Zootaxa 2536, pp. 1-35 : 5

publication ID	https://doi.org/ 10.5281/zenodo.196630
DOI	https://doi.org/10.5281/zenodo.6209453
persistent identifier	https://treatment.plazi.org/id/03D1713A-1C28-9220-9AE8-FF4D791642EC
treatment provided by	Plazi
scientific name	Haploniscus bihastatus
status	sp. nov.

Treatment

Haploniscus bihastatus View in CoL n. sp.

( Figs 2–5 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 )

Holotype: DIVA 2-HA233, adult male (stage VI), length 1.7 mm, coll.: RV Meteor, M63/2, DIVA 2 expedition, EBS station 89-6, 0°42.95’ N 5°31.29’ W, Guinea Basin, southeast Atlantic, ZMH K- 42426.

Paratypes: DIVA 2-HA330, adult male, length 1.8 mm, same locality as holotype, ZMH K- 42427. DIVA 1-HA235, adult male, length 1.75 mm, DIVA 1-HA276, adult male, length 1.87 mm, coll.: RV Meteor, M48/1, DIVA 1 expedition, EBS station 340-9, 18°18.3’ S 4°41.3’ E, 5395 m, Angola Basin, southeast Atlantic, ZMH K- 42428.

Etymology. From the Latin bi, meaning “two” and hastatus, “armed with a hasta”, a spear used by early Roman legionnaires. The name refers to the shape of the two large pleotelson processes, which resemble that of a hasta spearhead.

Diagnosis. Rostrum 0.5 head length. Pereonites 3–5 broadest. Posterior angles of pereonite 4 and anterior angles of pereonite 5 slightly produced; posterior body outline constricted in dorsal view, due to strong narrowing of posterior pereonites. Lateral margins of pleotelson slightly convex; pleotelson process length 0.9 pleotelson length, 2.7 width. Pleopod 1 lateral margins tapering only slightly, abruptly narrowing into neck (narrowest part); distance basal margin–neck 0.8 total length, neck width 0.4 maximum width; distolateral margins with small process each. Pleopod 2 protopod inner margin strongly concave; endopod length nearly 3.0 protopod length, 11.0 width; article 2 length 8.1 article 1 length.

Description (stage VI male). Body ( Fig. 2 View FIGURE 2 A–C) length 2.6 width. Head length 0.6 width. Pereonites 1 and 7 narrowest. Posterior angles of pereonites 2–7 and anterior angles of pereonites 3–5 acute;. Pleotelson length 0.3 body length, 0.8 width.

Antenna 1 ( Fig. 3 View FIGURE 3 F) peduncular article 1 length 1.6 width, with 2 penicillate setae distally; article 2 length 1.1 article 1 length, 2.0 width, with 2 simple and 4 penicillate setae distally; article 3 length 0.4 article 1 length, width 0.4 article 1 width, with 1 simple seta distally. Flagellum with 4 articles; article 1 shortest, article 2 longest, about 2.0 article 1 length, with 1 aesthetasc; article 3 with 2 aesthetascs and 1 simple seta, article 4 with 3 aesthetascs and 3 simple setae.

Antenna 2 ( Fig. 3 View FIGURE 3 E) peduncular articles 1 and 2 of subequal length and subequal width, article 2 with 2 simple setae; article 3 length 1.8 article 2 length, 1.3 width, with 1 simple seta distally, dorsal tooth with 2 simple setae; article 4 length 0.7 article 3 length, 0.9 width; article 5 length 2.2 article 3 length, 2.6 width, with at least 1 small penicillate seta and 1 simple seta; distal articles missing.

Pereopods ( Figs 3 View FIGURE 3 A–D; 4A–C): Basis of all pereopods with 2 long simple setae dorsally; basis of pereopods 2 and 3 with 2 penicillate setae, of pereopods 4–6 with 3 penicillate setae, of pereopod 7 with 1 penicillate seta dorsally. Ischium with 1 or 2 setae dorsally and ventrally each. Merus with 2 simple setae of different length distoventrally and 1 or 2 setae distodorsally, dorsal seta of pereopod 1 long and stout. Carpus with 2 or 3 simple setae ventrally; pereopods 2–7 with 1 penicillate seta (broken off on pereopod 4) and 1 short simple seta (broken off on pereopods 3, 4 and 6) distodorsally. Propodus with 2–5 setae ventrally, peropods 2–7 with 1 simple seta distodorsally (broken off on pereopods 4, 5 and 7), pereopod 5 with 1 penicillate seta distodorsally (broken off on pereopods 2–4, 6 and 7). Dactylus of pereopod 1 with 5, of pereopods 2–4 with 3 and of pereopods 6–7 with 1 or 2 setae near insertion of unguis.

Pleopod 1 ( Fig. 5 View FIGURE 5 A) length 0.8 pleotelson length, 2.0 width; widest part after 0.25 of its length.

Pleopod 2 ( Fig. 5 View FIGURE 5 B) protopod length 2.3 width, with about 10 long setae along outer margin.

Pleopod 3 ( Fig. 5 View FIGURE 5 C) endopod length 1.9 width. Exopod length 0.6 endopod length, 2.7 width.

Pleopod 4 ( Fig. 5 View FIGURE 5 D) endopod length 2.1 width. Exopod length 0.5 endopod length, 3.4 width, plumose seta length about 2.3 exopod length.

Pleopod 5 ( Fig. 5 View FIGURE 5 E) length 2.3 width.

Uropod ( Fig. 2 View FIGURE 2 C) distal article extending beyond posterior margin, not reaching tips of pleotelson processes.

Distribution. Found in the Guinea Basin and Angola Basin, Southeast Atlantic.