Leucothoe macquariae Krapp-Schickel & Broyer 2014, sp. nov.

Leucothoe macquariae sp. nov.

urn:lsid:zoobank.org:act: 6D484A0D-EC95-4D53-9C12-2E00B6A90F42

Figs 5, 11-12

Diagnosis

Eyes large, round. Cephalic keel not prominent. Mandibular palp art. 3 equal to longer than 1/2 length of art. 2. Gn 1 propodus l:b = 3-3.5, dactylus reaching nearly 1/2 of propodus length. P 5-7 basis oval broadened, with regularly rounded hind margin, ratio length to width 1.7 to 1.3; posterior margin in P 7 weakly serrate. Ep 3 posterodistally with rounded upturned corner. U 3 robust, rami somewhat unequal. T l:w <3.

Etymology

The latinized adjective refers to the type locality.

Type material

Holotype ♂ 7.5 mm in alcohol (Australian Museum, Sydney: P. 81138); Southern Ocean, Macquarie Island, Tottan Head, south end of Goat Bay; sta. MA 375; 30 Jan. 1978; 54.49167°S, 158.9625°E; 14 m depth; encrusting sponge, hydroid and tunicate mat on vertical wall of offshore rock.

Additional material

Australian Museum, Sydney

P. 80891: Southern Ocean, Macquarie Island, Garden Bay, near Hayter Rock; sta. MA 17; 23 Nov. 1977; 54.5°S, 159°E; 10 m depth; Macrocystis pyrifera (L.) Agardh holdfasts: 1 spec. immat. 4 mm.

P. 80892: Southern Ocean, Macquarie Island, Tottan Head, south end of Goat Bay; sta. MA 41; 30 Nov. 1977; 54.49167°S, 158.9625°E; 14 m depth; sponges, bryozoans and colonial tunicates from vertical rock wall of offshore rock: 3 spec. 6-7 mm.

P. 80893: Southern Ocean, Macquarie Island, Garden Bay; sta. MA 87; 7 Dec. 1977; 54.5°S, 159°E; 8 m depth; Macrocystis pyrifera holdfasts and sponges: 1 spec. immat. 3 mm.

P. 81121: Southern Ocean, Macquarie Island, Aerial Cove; sta. MA 108; 12 Dec. 1977; 54.5°S, 159°E; 5 m depth; sponges and bryozoans from sheltered base of vertical rock face: 11 spec. 3-6 mm, 1 spec. 8 mm.

P. 81122: Southern Ocean, Macquarie Island, rocks off end of Garden Bay Peninsula; sta. MA 123; 16 Dec. 1977; 54.5°S, 159°E; 14 m depth; sponges and Codium from base of rock: 27 spec. 4-8 mm.

P. 81123: Southern Ocean, Macquarie Island, rocks off end of Garden Bay Peninsula; sta. MA 125; 16 Dec. 1977; 54.5°S, 159°E; 11 m depth, sponges and red algae from vertical rock face: 1 spec. juv. 2.8 mm.

P. 81125: Southern Ocean, Macquarie Island, south-east corner of Gorilla Head Rock; sta. MA 146; 23 Dec. 1977; 54.4875°S, 158.96033°E; 12 m depth; sponges and tunicates from exposed rock walls: 11 spec. 4-8 mm.

P. 81126: Southern Ocean, Macquarie Island, south-east corner of Gorilla Head Rock; sta. MA 148; 23 Dec. 1977; 54.4875°S, 158.96033°E; 9 m depth; slate-grey sponge from underside of sand and gravel bottom in Macrocystis pyrifera bedrock overhang: 11 spec. 4-6 mm.

P. 81127: Southern Ocean, Macquarie Island, south-east corner of Gorilla Head Rock; sta. MA 291; 13 Jan. 1978; 54.6°S, 158.9°E; 14 m depth; sponges on rock wall on sandy gravel bottom: 3 spec. 5-6 mm. P. 81128: Southern Ocean, Macquarie Island, Sandy Bay, off rock platform 200 m S of hut; sta. MA 241; 1 Jan. 1978; 54.6°S, 158.9°E; 16 m depth; sponge, hydroid and bryozoan mat on face of large boulder on gravel bottom: 4 spec. 6 mm.

P. 81129: Southern Ocean, Macquarie Island, Green Gorge in front of hut; sta. MA 245; 7 Jan. 1978; 54.6°S, 158.9°E; 14 m depth; sponges from boulders on sand and gravel bottom in Macrocystis pyrifera bed: 3 spec. juv. 2.5-3 mm..

P. 81130: Southern Ocean, Macquarie Island, Green Gorge, off rock platform 500 m S of hut; sta. MA 249; 7 Jan. 1978; 54.6°S, 158.9°E; 18 m depth; sponges, bryozoans, tunicates and algae from boulders on rocky gravel bottom: 4 spec. 4-7 mm.

P. 81131: Southern Ocean, Macquarie Island, Green Gorge off rock platform; sta. MA 251; 54.6°S, 158.9°E; 18 m depth; sponges, bryozoans, tunicates and algae from boulders on rocky gravel bottom:> 20 spec. 5-8 mm.

P. 81132: Southern Ocean, Macquarie Island, Green Gorge, off rock platform 500 m S of hut; sta. MA 287; 12 Jan. 1978; 54.6°S, 158.9°E; 11 m depth;yellow sponge on vertical rock wall in sheltered crevice: 1 ♀ 10 mm, 4 spec. 6 mm.

P. 81133: Southern Ocean, Macquarie Island, Green Gorge, Macrocystis beds east of hut; sta. MA 149; 23 Jan. 1977; 54.4875°S, 158.96033°E; 9 m depth; orange, white, yellow and green sponges, hydoids, bryozoans and tunicates from sheltered cave roof: 3 spec. 3-6 mm.

P. 81134: Southern Ocean, Macquarie Island, Tottan Head, south end of Goat Bay; sta. MA 367; 30 Jan. 1978; 54.49167°S, 158.9625°E, 10 m depth, yellow sponges on vertical wall of offshore rock: 4 spec. 7-8 mm.

P. 81136: Southern Ocean, Macquarie Island, Tottan Head, south end of Goat Bay; sta. MA 370; 30 Jan. 1978; 54.49167°S, 158.9625°E; 14 m depth; red algae, hydroids and sediment on sheltered vertical wall of offshore rock: 1 spec. 6 mm.

P. 81137: Southern Ocean, Macquarie Island, Tottan Head, south end of Goat Bay; sta. MA 374; 30 Jan. 1978; 54.49167°S, 158.9625°E; 14 m depth; encrusting sponge mat on vertical wall of offshore rock: 2 spec. 6 mm.

P. 81138: Southern Ocean, Macquarie Island, Tottan Head, south end of Goat Bay; sta. MA 375; 30 Jan. 1978; 54.49167°S, 158.9625°E; 14 m depth; encrusting sponge, hydroid and tunicate mat on vertical wall of offshore rock:> 20 spec. 7-8 mm.

P. 81140: Southern Ocean, Macquarie Island, far rocks off end of Garden Bay Peninsula; sta. MA 379; 01 Feb. 1978; 54.49917°S, 158.9591°E; 11 m depth; sponges, hydrozoans, bryozoans from under rock overhangs and in small caves in exposed area: 2 spec. 5-6 mm, 1 ♀ ov. 7 mm (slide).

NIWA, Wellington

NIWA 7848: sta. C0730; 24 Nov. 1961; south of Macquarie Island; 54°55.00’S, 158°47.00’E; 110 m depth: 2 spec. 5 mm.

NIWA 20875: sta. TAN 0402/231; 04 Mar. 2004; off Balleny Islands; 67.4205017°S, 163.9391632°E to 67.4205017°S, 163.9391632°E; 111 m depth: 4 spec. 3.5-5 mm.

? NIWA 7850: sta. B0221; 21 May 1960; New Zealand, Foveaux Strait; 46° 40.00’S, 168°16.80’E; 31 m depth: ♀ ov. 5 mm, ♀ ov. 3 mm.

? NIWA 7856: sta. A0013; 29 Jan. 1955; New Zealand, near Auckland; 35.9832993°S, 176.1166992°E; 227 m depth: 1 spec. in 5 slides, 6 spec.

? NIWA 7857: no locality: 3 spec. 5-6 mm.

Description

Length

5-8 mm.

Head

Anterior margin rounded, anterodistal margin rectangular with rounded corner. Mid-cephalic keel not prominent. Rostrum small.

Eyes large, round.

Antennae short and robust, A 1 <1/3 of body length, flagellum 10-12-articulate, peduncle art. 1 width twice the one of article 2, disto-inferiorly without acute tooth, length art. 1 subequal to art. 2, art. 3 about 1/3-1/2 of art. 2, acc. flagellum not seen. Peduncle art. 3 + flagellum shorter than peduncle arts 1+2.

A 2 subequal in length to antenna 1, peduncle art. 4> art. 5, flagellum 7-10 arts.

Mouthparts: Mandibles lacking molars, incisor and lacinia mobilis dentate; palp 3-articulate, art. 2 with 12 long lateral setae, art. 3 with 2 distal setae, equal to half length of art. 2. Mx 1 palp sometimes with indistinct suture, which has been recorded for the first time by White & Thomas (2009). Mx 2 with riding position of the plates, OP narrow.

Mxp robust, IP small, nearly fully fused medially, OP absent; palp articles unusually wide, subquadrate.

Peraeon

Cx 1 smooth, length> width; anterior margin smooth, facial setae absent, inferior margin smooth.

Gn 1 basis scarcely inflated, anterior margin with some short setae; ischium smooth; carpus basis more than half as long as propodus, distal part linear, narrow, about 6 x longer than wide; propodus straight, about 3-3.5 x as long as wide, palm with 8 short setae; dactylus smooth, reaching nearly 1/2 propodus length.

Cx 2 subquadrangular, about as long as wide, much wider than Cx 3, distally smooth; anterior margin rounded, anterodistal corner rectangularly rounded, inferior margin straight, posterior margin excavated, facial setae absent.

Gn 2 basis not inflated, on anterior margins 3 short setae; carpus nearly reaching one third of propodus length, curved, distally rounded, densely setose; propodus anterodistally without prolongation, with a bundle of setae, posterior margin in male with many low humps, in female smooth, palm convex, proximally near dactylus-end no corner; facial setae medially and submedially present; dactylus curved, both margins smooth, bare, reaching somewhat more than half of propodus length.

Cx 3 length> width, anterior and posterior margin straight, subrectangular, smooth, facial setae absent.

Cx 4 length subequal to width, smooth, bare, anterior margin straight, distal margin oblique, posterior margin clearly shorter than anterior one, not excavate, facial setae absent.

P 3, 4 basis very narrow, a bit wider than merus; dactylus reaching nearly half length of propodus, posterior margins naked.

Cx 5-7 facial setae absent.

P 5-7 similar, bases length:width ratio about 1.3 (P 5) to 1.2 (P 7), anterior margins with small weak spines, posterior margins in P 5, 6 smooth, in P 7 weakly serrate. Merus to propodus anterior margin with small spines, in merus also posterior margin; merus with posterodistal corner lengthened.

Pleon

Ep 1-3 bare. Ep 2 posteroventral corner scarcely lengthened and rounded. Ep 3 posteroventral corner blunt, with small rounded and somewhat upturned corner.

Uropods: U 2 the shortest, with unequal rami (ratio about 1.4), the shorter one shorter than peduncle. U 3 peduncle more robust than in the other species, margine spinose; rami unequal, ratio 1.2 to 1.25.

Telson ratio l:w = 2.7, margins smooth, tip acute.

Distribution

sub-Antarctic (Macquarie Island, 54°S) and Antarctic waters (Balleny Islands, 67°S); records from temperate waters (New Zealand: 35°S, 46°S) to be confirmed.

Habitat

From Codium sp., red algae, Macrocystis pyrifera holdfasts, sponges, bryozoans, colonial tunicates and sand or gravel bottom.

Depth range

5- 227 m.

Remarks

This species has some similarity to L. antarctica, but P 7 basis is less wide and has always a lengthened posterodistal corner (nearly semi-circularly rounded, corner not or scarcely lengthened in L. antarctica); Gn 1 propodus is much more robust here and U 3 rami are unequal (vs. U 3 slender with equal rami in L. antarctica); Ep 3 has a somewhat upturned rounded posterodistal corner (vs. rectangular corner in L. antarctica).