Leucothoe macquariae, Krapp-Schickel & Broyer, 2014

Krapp-Schickel, Traudl & Broyer, Claude De, 2014, Revision of Leucothoe (Amphipoda, Crustacea) from the Southern Ocean: a cosmopolitanism concept is vanishing, European Journal of Taxonomy 80, pp. 1-55 : 21-27

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 ).

Figures

Fig. 5. Distribution of Leucothoe antarctica Pfeffer, 1888, L. campbelli sp. nov., L. longimembris sp. nov., L. macquariae sp. nov. and L. merletta sp. nov. The hydrographic fronts shown on the map are from north to south: the Sub-Tropical Front, the Sub-Antarctic Front, the Antarctic Polar Front and the Southern Antarctic Circumpolar Current Front. Mean position of the fronts according to Sokolov & Rintoul (2009). TL = type locality.

Fig. 11. Leucothoe macquariae sp. nov., NIWA 7856 sta. A0013 1 spec. in 5 slides. A 1, 2 = antenna 1, 2; Md = mandible; Mx 1, 2 = maxilla 1, 2; Mxp = maxilliped; Gn 1 = gnathopod 1; Gn 1’ = gnathopod of other specimen from same sample; Gn 2 = gnathopod 2; Gn 2’, Gn 2" = second gnathopods of other specimens from same sample.

Fig. 12. Leucothoe macquariae sp. nov., NIWA 7856 sta. A0013 1 spec. in 5 slides. P 3-7 = peraeopod 3-7; P 4’, P 6’ = peraeopods of other specimens; Ep 3 = third epimeral plate; U 1-3 = uropod 1-3; U 2’, U 3’ = uropods of other specimens; T = telson.