Haptocallisoma abyssi ( Oldevig, 1959 ) Oldevig, 1959

Horton, Tammy & Thurston, Michael H., 2015, A revision of the genus Paracallisoma Chevreux, 1903 (Crustacea: Amphipoda: Scopelocheiridae: Paracallisominae) with a redescription of the type species of the genus Paracallisoma and the description of two new genera and two new species from the Atlantic Ocean, Zootaxa 3995 (1), pp. 91-132 : 109-115

publication ID	https://doi.org/ 10.11646/zootaxa.3995.1.12
publication LSID	lsid:zoobank.org:pub:DC0AEC92-B7C7-4310-BB9D-F9BE6594A98A
DOI	https://doi.org/10.5281/zenodo.3512148
persistent identifier	https://treatment.plazi.org/id/B22687A6-7E39-FFEE-FF13-69D3848EFD51
treatment provided by	Plazi
scientific name	Haptocallisoma abyssi ( Oldevig, 1959 )
status	comb. nov.

Treatment

Haptocallisoma abyssi ( Oldevig, 1959) View in CoL comb. nov.

Figs 9–14 View FIGURE 9 View FIGURE 10 View FIGURE 11 View FIGURE 12 View FIGURE 13 View FIGURE 14

Scopelocheirus abyssi Oldevig 1959: 16 View in CoL , figs 1–3.— Barnard & Karaman 1991: 528.— Vinogradov, Vereschchaka & Vinogradov 1996: 8.— Brandt 1997: 1540 (table 2).

Paracallisoma abyssi .— Horton 2006: 20, table 2.— Horton, Thurston & Duffy 2013: 354.— Kilgallen & Lowry 2015: 22 View Cited Treatment .

Type material. Lectotype and 23 paralectotype specimens, maximum length about 15 mm, Swedish Museum of Natural History, Stockholm, “ “Svenska Djupet” 77°39’N. 01°17’O. 3200 m, Biloculina-lera, bottent. –1°, 4. 27.7 1898. Svenska Spetsb.-Exp.” The material is in poor condition and no specimen is complete. A female specimen about 12 mm long and thought to be that used by Oldevig for his description is selected here as a lectotype. The dissected carcass of the lectotype is registered under Amphipoda Type no. 2343 with three slides of dissected parts under Amphipoda Type no. 5356, 5357 and 5362. The carcasses of paralectotype specimens ‘a–e’ are registered under Amphipoda Type no. 5351–5355 with associated slides registered under Amphipoda Type no. 5358–5361.

Material examined. Type series: Greenland Sea, Boreas Basin. Swedish Spitzbergen Expedition, “Swedish Deep”, 27 July 1898, 77°39’N 01°17’E, 3200 m, lectotype and 23 paralectotype specimens.

Additional material. Faroe-Shetland Channel. Station 57060#1, 11–13 August 2002, 61°39.16' N, 01º13.97' W, DEMAR, 1611 m, one adult female 13.9 mm (dissected carcass and four slides ( NHMUK 2015. 2837)), one adult male 13.6 mm (one slide NHMUK 2015. 2838), four females, one immature male and four juveniles ( NHMUK 2015. 2839–2847). Station 53979#1, 16–17 August 1996, 61°28.72’ 02°47.66’W, fish trap, 1396 m, two specimens.

Norwegian Sea. Midnatssol Exploration Well, Station TL/ 280807 /010#2, 28–29 August 2007, 64°09.93’N 05°16.75’E, ROV-deployed trap, 928 m, 42 specimens. Haklang Exploration Well, Station TL/ 171008 /031#1, 17 October 2008, 67°02.81’N 07°03.53’E, ROV-deployed trap, 1248 m, one specimen. Gro Exploration Well, Station LE/ 090609 /005#1, 9–10 June 2009, 66°08.88’N 03°56.41’W, ROV-deployed trap, 1380 m, three specimens.

Description. Based on lectotype, immature female, ~ 12 mm (G1–2, P3–7, E1–3, U1–2); paralectotype ‘a’, immature female, ~ 12 mm (A2, L, Md, Mx1–2, Mxp); paralectotype ‘b’, sex unknown, ~ 12 mm (U3, T); paralectotype ‘c’, immature female, ~ 13 mm (A1); paralectotype ‘d’, sex unknown, ~ 12 mm (C).

Head exposed, deeper than long, lateral cephalic lobe small, subacute; rostrum very short; interantennal carina sinuous proximally, not notched. Antenna 1 short, 0.12 x body; peduncle article 1 short, length 0.9 x breadth, without posterodistal spine or lobe; peduncular article 2 short, 0.23 x article 1; peduncle article 3 short, 0.16 x article 1; flagellum 8-articulate, callynophore present, two-field; accessory flagellum long, 0.68 x primary flagellum, 3-articulate, article 1 long, 3.4 x article 2. Antenna 2 length 3 x antenna 1; peduncle article 1 greatly enlarged, not covering article 2; weakly geniculate between peduncle articles 3 – 4, article 3 short 0.4 x article 4; peduncle articles 4 and 5 not enlarged; flagellum well developed, 35-articulate, calceoli absent.

Mouthpart bundle subquadrate. Epistome and upper lip separate; epistome straight; upper lip not produced, slightly rounded. Mandible incisors symmetrical, large, with slightly convex margins; left lacinia mobilis incomplete (distal part broken), right lacking; accessory setal rows each with three robust simple setae; molar a conical structure; palp article 1 short, length 0.75 x breadth, without setae; article 2 slender, length five x breadth, with 12–14 submarginal distolateral A2-setae; article 3 missing. Maxilla 1 inner plate tapering distally, inner margin fully setose, with twelve pappose setae; outer plate broad with eleven setal teeth in 7/4 arrangement; outer row with ST1-2 large, slender, without cusps, ST3 two-cuspidate, ST4-5 three-cuspidate, ST6 two-cuspidate, ST7 without cusps, inner row with STA-C slender, without cusps, STD three-cuspidate terminally; palp large, twoarticulate, article 1 short, article 2 widening distally with seven terminal robust setae, flag seta and one subterminal seta; Maxilla 2 inner plate broad, tapering, with twelve pappose setae in oblique mediofacial setal row, with terminal spines and setae; outer plate slightly longer than inner with apicomedial spines and setae. Maxilliped inner plate large, subrectangular, emarginate distally with three apical nodular setae, with one apicomedial seta, oblique facial setal row strong with eleven pappose setae; outer plate medium size, broadly rounded with twelve apical plumose setae, with 15 medial small nodular setae and two longer robust setae at the distomedial corner; palp large, 4-articulate, article 2 longest, slender, length 2.4 x breadth, 1.8 x article 3; article 3 long, slender, length 2.2 x breadth; dactylus well-developed, with 3 sub-terminal setae.

Gnathopod 1 simple; coxa broad, as long as coxa 2, basis long, slender, length 3.5 x breadth, anterior margin smooth, without setae; ischium length twice breadth, anterior margin smooth, posterior margin with a few simple setae; merus, posterior margin with a few simple setae distally; carpus subrectangular, long, length 2.8 x breadth; propodus as long as carpus, tapering distally, posterior margin with six groups of simple, slender setae, apex with numerous distal robust pappose setae; dactylus posterior margin with three small teeth. Gnathopod 2 minutely subchelate; coxa large, narrower than coxa 3; carpus long, length 2.8 x breadth; propodus suboval, slightly narrowing distally, short, 0.68 x carpus, length twice breadth, posterior margin with seven groups of slender robust setae, apically with row of distally plumose setae decreasing in size towards palm; palm transverse indented medially with convex serrate margin distally; dactylus reaching corner of palm, posterior margin smooth. Pereopod 3 prehensile; coxa large, broad, subrectangular; basis robust, sinuous and slightly expanded distally; merus slightly expanded anteriorly; propodus posterior margin with eight robust setae and two distal locking setae; dactylus long, slender and curved to close along palm of propodus. Pereopod 4 prehensile; as pereopod 3 except coxa width 1.2 x depth, with well-developed narrowly rounded posterior lobe. Pereopod 5 coxa posterior lobate; basis widely expanded, posterior margin and posterodistal lobe broadly rounded, extending to distal margin of ischium; merus expanded posteriorly with robust setae on anterior and posterior margins; carpus shorter than propodus; propodus long, length 3.9 x breadth, anterior margin with one single and six pairs of robust setae and one pair of locking setae; dactylus long, 0.55 x propodus, curved to close against palm of propodus. Pereopod 6 coxa small, posterior lobate; basis anterior margin, convex and rounded, lacking robust setae, proximal posterior margin expanded, rounded, convex, with one short simple seta at angle proximal to excavate distal posterior margin, round posterodistal lobe not extending to merus; merus 1.2 x merus of pereopod 5; distal articles lost. Pereopod 7 (weakly prehensile); coxa small, posterior lobate; basis anterior margin convex with one short slender seta proximally, posterior margin broadly expanded, rounded, convex with five short simple setae along margin, excavate distally with a short, rounded, posterodistal lobe not extending to merus; merus weakly expanded posteriorly; distal articles lost.

Pleonites 1–3 smooth dorsally. Epimeron 1 rounded posteriorly; anterior margin slightly concave. Epimeron 2 anterior margin sinuous, anterior corner rounded; posterior margin convex, posteroventral corner slightly produced. Epimeron 3 subquadrate, posterior margin slightly convex, posteroventral corner not produced, ventral margin with seven small robust setae.

Gills on pereopods 2–7. Brood plates on pereopods 2–5.

Uropod 1 peduncle long, with one apicomedial robust seta and eight dorsomedial setae; inner ramus 0.61 x peduncle, with two medial robust setae and microsetose lateral margin; outer ramus 0.91 x inner ramus, with one lateral robust seta and microsetose medial margin. Uropod 2 peduncle long, with just one apicomedial robust seta; inner ramus 0.88 x peduncle, with two medial robust setae and five lateral robust setae; outer ramus, 0.75 x inner ramus, with two lateral robust setae and a microsetose medial and distolateral margins. Uropod 3 peduncle short, length 1.5 x breadth, with one apicolateral seta and four medial setae; inner ramus apex lost, at least 1.5 x peduncle, with six medial robust setae and twelve medial slender plumose setae and four lateral robust setae; outer ramus apex lost, at least 1.5 x peduncle, two-articulate; article 1 with four medial robust setae and a microsetose medial margin and six lateral robust setae. Telson longer than broad, slightly tapering, length 1.6 x breadth, cleft 64%, with 4/5 robust setae on each lobe, distal margins shallowly incised, with one small immersed seta.

Additional description. Adult female 13.9 mm and adult male 13.6 mm from Faroe-Shetland Channel, Station 57060#1, 11–13 August 2002, 61°39.16' N, 01º13.97' W, DEMAR, 1611m, DTI SEA4 cruise.

Mandible as in lectotype except left lacinia mobilis a stemmed asymmetric blade, accessory setal row with two robust setae; palp article 2 with 16 submarginal distolateral A2-setae; article 3 slender, blade-like, with 18 D3 setae along distal two thirds of the margin, and three E3 setae.

Gnathopod 2 as in lectotype except dactyl (damaged) not reaching palm edge, with denticulate posterodistal margin, three subterminal setae.

Pereopod 5 prehensile; anterior margin with one robust seta distally, posterior margin with eight short robust setae; merus with six robust setae on posterior margin and five groups of robust setae on anterior margin; propodus long, length 4.2 x breadth, anterior margin with eight pairs of robust setae and one pair of distal locking setae, posterior margin with two slender setae; dactylus long, slender, tip broken. Pereopod 6 prehensile; basis anterior margin rounded proximally with two long simple setae, posterior margin with seven short simple setae along margin, round posterodistal lobe extending to merus; propodus long, length 4.2 x breadth, anterior margin with five pairs of robust setae, five single robust setae and a pair of locking setae, posterior margin with five slender setae; dactylus long, slender, almost straight. Pereopod 7 basis anterior margin straight with five short robust setae, posterior margin with twelve short simple setae along margin; propodus long, length 4.3 x breadth, anterior margin with one single and six pairs of robust setae and one pair of distal locking setae; dactylus long, slender, almost straight.

Urosomite 1 concave before low rounded boss. Uropod 1 peduncle very long, 1.85 x inner ramus, with one apicolateral robust seta, one apicomedial robust seta, and 14 dorsomedial setae; inner ramus, 0.54 x peduncle, with three medial robust setae, and a microsetose lateral margin; outer ramus 0.9 x inner ramus, with one dorsolateral robust seta and a microsetose medial margin. Uropod 2 peduncle long, 1.32 x inner ramus, with one apicolateral robust seta, one apicomedial robust seta, seven dorsomedial setae, and four dorsolateral robust setae; inner ramus, 0.8 x peduncle, with four medial robust setae and six lateral robust setae; outer ramus, 0.7 x inner ramus, with three lateral robust setae and a microsetose medial margin. Uropod 3 peduncle short, length and breadth subequal, with one apicolateral robust seta, one apicomedial robust seta, one distoventral robust seta, and seven slender simple medial setae; inner ramus, tip lost, at least 1.7 x peduncle, longer than article 1 of outer ramus with five medial robust setae, six medial slender plumose setae and three lateral robust setae; outer ramus, 2-articulate, article 2 tip lost, article 1 at least 1.6 x peduncle with four medial robust setae, six lateral robust setae and a microsetose distomedial margin.

Sexual dimorphism. Male antenna 1 short, length 0.12 x body; peduncle article 1 short, length 0.7 times breadth, with 16 short plumose setules on posterior margin; peduncle article 2 short, 0.45 x article 1; peduncle article 3 short, 0.25 x article 1; flagellum 8-articulate, with posterodistal setae; callynophore strong, two field; accessory flagellum long, 0.73 x primary flagellum, 4-articulate, Article 1 long, 4.0 x article 2. Male antenna 2 length four x antenna 1; peduncle with brush setae; peduncle article 1 greatly enlarged, not covering article 2; weakly geniculate between peduncle articles 4–5, article 3 short, 0.7 x article 4; peduncle articles 4 and 5 not enlarged; flagellum well developed, 41–articulate; calceoli present.

Remarks. The original description of this species is very short with only pereopod 6, pereopod 7, and telson illustrated ( Oldevig 1959). A lectotype has been selected from Oldevig’s material and the species is redescribed and re-illustrated using this specimen, others from the type series, and new material from the Faroe-Shetland Channel. The characteristic prehensile pereopods 3–7 and the broadly expanded basis of pereopod 5 justify the inclusion of H. abyssi in the new genus Haptocallisoma .

Depth range. 1611–3200 m.

Distribution. Boreas Basin between Greenland and Svalbard, Faroe-Shetland Channel.