Zeaphoxus zealandicus, Taylor & Peart, 2023

Taylor, Joanne & Peart, Rachael A., 2023, A New Genus and Five New Species of Phoxocephalidae (Crustacea: Amphipoda) from the Eastern Tasman Sea, the Otago Shelf, and The Snares, New Zealand, Records of the Australian Museum (Rec. Aust. Mus.) 75 (4), pp. 567-600 : 595-598

Zeaphoxus zealandicus sp. nov.

urn:lsid:zoobank.org:act:894698D8-658B-4583-BB07-35E836379B24

Figs 20–22

Holotype. AM P25882 , female “y-2”, 11.7 mm, Otago Shelf , New Zealand, 45°48'S 170°51'E, gravel, sand, mud bottom, 65 m, P. K. Probert on RV Munida, MU74 /198, 15 October 1974.

Etymology. Named for New Zealand.

Diagnosis. Eyes present. Head without constriction in dorsal view.Antenna 1 peduncular article 1 ventral apex not ensiform, peduncle article 2 shortened. Antenna 2 peduncle article 3 with robust setae, article 4 shortened with facial robust setae. Right mandible lacinia mobilis bifid, proximal branch same length as distal branch. Maxilla 1 inner plate large, outer plate with 11 multicuspidate robust setae. Maxilliped palp article 3 weakly produced. Posteroventral corner of coxae 1–3 without tooth. Gnathopods 1–2 carpus not cryptic. Gnathopod 2 similar sized to gnathopod 1, propodus with 1 robust seta near palmar corner. Pereopods 3–4 carpus setae placed near anterodistal margin. Robust setae forming dominant posterior element on pereopods 3–4 carpus. Pereopod 5 basis broad. Pereopod 6 basis anterior margin without setae, posterodistal corner not produced to form lobe. Pereopod 7 merus, carpus, and propodus narrow; dactylus long. Urosome without basoventral setae. Epimera 1–2 without facial setae. Uropods 1–2 rami never fully spinose, rami with articulate enlarged apical nails, lacking accessory nails. Uropod 1 peduncle with 2 robust setae on dorsolateral margin. Uropod 2 peduncle dorsal margin with short apical robust setae and elongate proximal setae. Uropod 3 outer ramus article 2 with 2 long apical setae; inner ramus medium length, about 0.5 × length of outer. Telson deeply cleft, apically with 1 robust seta per lobe, marginally without setae on each side, with 1 small lateral robust seta.

Description. FEMALE, based on AM P25882, female “y-2” holotype, 11.7 mm.

Head: Eyes large, largely occluded with pigment. Head about 0.19 × body length, greatest width about 0.75 × length; rostrum not constricted, broad, reaching middle of article 2 on antenna 1. Antenna 1 peduncle article 1 1.7 × as long as wide, 2.3 × as wide as article 2, ventral margin with about 9 setules, weakly produced dorsal apex with 1 seta; article 2 about 0.7 × as long as article 1, with ventral horseshoe cycle of 9 setae; primary flagellum 12-articulate about 0.6 × as long as peduncle, lacking large aesthetascs; accessory flagellum 10-articulate. Antenna 2 peduncle article 4 main setal formula = 5-3, dorsal margin with notch with 6 setae, ventral margin with 10–11 groups of 1–4 elongate to medium setae, 1 distoventral elongate robust seta; article 5 almost 0.7 × as long as article 4, facial setal formula = 3-2, dorsal margin naked, ventral margin with 10 sets of 1 elongate seta each, 1 distoventral medium robust seta; flagellum about as long as articles 4–5 of peduncle combined, 12-articulate.

Mouthparts: Mandibles with medium palpar hump; right incisor with 3 teeth; left incisor with 2 weak humps in 2 branches; right lacinia mobilis bifid, distal branch flabellate, not shorter than proximal, proximal branch weakly denticulate; left lacinia mobilis with 4 teeth; right accessory setal row with 7 multicuspidate stout setae; molar bulbous, weak, with 1 large serrate robust seta and 2 much smaller simple robust setae, no disjunct robust setae, each molar with patch of fine setae; palp article 1 short, article 2 with 5 elongate inner setae and no outer setae, article 3 about 1.1 × as long as article 2, oblique apex with 10 elongate robust setae. Maxilla 1 inner plate large, with 2 elongate subapical pappose setae, 2 apicolateral much shorter setae; palp article 2 with 1 medial marginal robust seta, and 5 apical robust setae and 5 submarginal slender setae. Maxilla 2 plates extending subequally, of subequal breadth, outer with 5 apicolateral setae, inner with 2 medial setae. Maxilliped inner plate with 2 large apical robust setae, 3 apicofacial plumose setae, 4 medial plumose setae; outer plate with 12 medial and apical seta-teeth, 6 apicolateral setae; some setae set into cuspidate recesses; palp article 1 with 1 apicolateral seta, medial margin of article 2 moderately setose, article 3 scarcely produced, with 6 facial setae, 3 lateral setae, nail of article 4 immersed and almost absent, with 2 accessory setules.

Pereon: Coxa 1 not expanded distally, anterior margin almost straight, main ventral setae of coxae 1–4 = 20-19- 19-31, posterior most seta of coxae 1–2 shortened; anterior and posterior margins of coxa 4 weakly divergent, posterior margin almost vertical, straight, posteroventral margin not bevelled, posterodorsal corner rounded, posterodorsal margin of medium length, concave, width to length ratio of coxa 4 = 18:21. Coxae 5–7 posteroventral setule formula = 3-7-1. Gnathopods 1–2 weakly diverse, gnathopod 2 slightly enlarged, width ratios of carpus-propodus on gnathopods 1–2 = 12:14 and 13:19, length ratios = 26:27 and 19:33; palmar humps short to medium, palms acute, with 1 robust seta defining palm; gnathopods 1–2 carpus medium and short respectively, of gnathopod 1 ovate, posterior margin of gnathopod 1 flat, of gnathopod 2 lobate, of gnathopod 2 short, triangular. Pereopods 3–4 similar, facial setae formula on merus = 11, on carpus = 9; main robust seta of carpus extending to M.110 on propodus, carpus without posteroproximal robust setae; setal formula of propodus = 4-2 plus mid-distal robust setae very elongate and often curved, robust setae acclivity on inner margin of dactyls of pereopods 3–4 weak to absent. Pereopods 5–6 merus-carpus narrow, facial robust setae rows poorly developed, facial ridge formula on basis of pereopods 5–7 = 0-1-1, ridge of pereopod 7 long; width ratios of basis, merus, carpus, propodus of pereopod 5 = 23:10:8:4, of pereopod 6 = 35:13:9:6, of pereopod 7 = 42:11:8:4, length ratios of pereopod 5 = 33:12:15:14, of pereopod 6 = 48:25:29:22, of pereopod 7 = 55:12:13:15. Pereopod 5 basis tapering distally. Pereopod 7 basis reaching middle of merus. Pereopods 5 and 7 merus without especially elongate posterodistal lobe; medial apex of propodus truncate, uncombed, deeply fimbriate.

Pleon: Epimeron 1 posteroventral corner rounded, posterior margin convex, with setule (not shown), anteroventral margin with 6–9 short setae, ventral margin with 19–21 elongate setae, ragged anteriorly (some broken off in figure). Epimeron 2 posteroventral corner rounded, posterior margin convex, with 5 setules, facial setae = 2–3 irregular rows of 19, anterior setae irregular and set vertically. Epimeron 3 posteroventral corner subquadrate, posterior margin straight, scarcely serrate, with 3 setules, ventral margin with 6 widely spread setae, face with obliquely horizontal posterior row of 14 setae. Urosomite 1 with 3 midventral setae; articulation line complete in middle. Urosomite 3 weakly protuberant dorsally. Uropods 1–2 rami with articulate enlarged apical nails, lacking accessory nails. Uropod 1 peduncle with 2 small apicolateral robust setae and 8 basofacial setae, medially with 4 small marginal robust setae, outer ramus with 3 dorsal robust setae, inner with 1 medial. Uropod 2 peduncle with 12–14 dorsal setae and 3 apical robust setae, medially with 1 medium apical robust seta, outer ramus with 2 dorsal robust setae, inner naked. Uropod 3 peduncle with 6 apicoventral robust setae, dorsally with 1 lateral robust seta, 1 medial robust seta; rami submasculine, inner extending to M.80 on article 2 of outer ramus, apex with 5 setae, other margins naked, article 2 of outer ramus tiny, with 2 elongate setae, medial margin of article 1 with 4 setae, lateral margin with 4 acclivities, setal formula = 1-1-1-1-2 setal formula = 1-1-1-1-0. Telson elongate, length to width ratio = 15:30, fully cleft, each apex broad, truncate, acclivity absent, with tiny lateral robust seta, setule next medial shorter than robust seta, next medial robust setae elongate, basodorsal setules diverse.

MALE: Unknown.

Remarks. Zeaphoxus zealandicus sp. nov. differs from Z. senecio sp. nov. in having fewer robust setae on the dorsolateral margin of peduncle on uropod 1, in having variably sized robust setae on the dorsal margin of peduncle on uropod 2 and in having the proximal branch of the right lacinia mobilis more similar in size to the distal branch.

Distribution. New Zealand, Otago Shelf; 65– 93 m.

Figures

Figure 20. Zeaphoxus zealandicus sp. nov., holotype, female “y-2”, AM P25882, 11.7 mm, Otago Shelf, New Zealand. Scales represent 0.1 mm.

Figure 21. Zeaphoxus zealandicus sp. nov., holotype, female “y-2”, AM P25882, 11.7 mm, Otago Shelf, New Zealand. Scales represent 0.2 mm.

Figure 22.Zeaphoxus zealandicussp.nov.,holotype,female “y-2”,AM P25882,11.7 mm,OtagoShelf,New Zealand.Scalesrepresent 0.2 mm.