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

Leucothoe merletta sp. nov.

urn:lsid:zoobank.org:act: 6C2BCD72-777F-4825-B595-A23EBFE445C9

Figs 5, 13-14

Diagnosis

Eyes round, yellowish. Mandibular palp art. 3 nearly as long as art. 2. Cx 2 smooth, in shape of a parallelogram, anterodistal corner acutely lengthened. Cx 4 also with anteridistal corner acutely lengthened, but posterior margin much shorter than anterior one. Gn 1 propodus l:w = 4, dactylus reaching nearly 1/2 of propodus length. P 5-7 basis oval, with regularly rounded hind margin, ratio l:w about 1.5; posterior margin in P 7 smooth. Ep 2 distoposterior corner slightly upturned, Ep 3 posterodistally with rectangular corner. T l:w not known.

Etymology

In Italian “merletto” is the bobbin lace; as the very acutely elongated Cx 2 and Cx 4 can remind on lacecollars, this epitheton (Latinized flexible adjective) was coined.

Type material

Holotype ♀ 2.5 mm, Belgian-Dutch Antarctic Expeditions (RBINS, I.G. 23694 / INV. 103463); EABN 1966-67: sta. 238; 3 Feb. 1967; Breid Bay, Baie Léopold; 70°19’S, 24°14’E; 200 m; bottom trawl; coll. M. Steyaert & M. Meisch.

Description

Length 2.5 mm.

Head

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

Eyes round, yellow.

Antennae short and robust, A 1 flagellum 5-articulate, peduncle art. 1 subequal in length but twice the width of article 2, disto-inferiorly without acute tooth, art. 3 nearly 1/2 of art. 2, acc. flagellum not seen. Peduncle art. 3 + flagellum about as long as peduncle art. 2.

A 2 subequal in length with antenna 1, peduncle art. 4> art. 5, flagellum 4 arts.

Mouthparts: Mandibles lacking molars, incisor and lacinia mobilis dentate; palp 3-articulate, art. 2 with 4 long lateral and one distal setae, art. 3 with 2 distal setae, subequal to art. 2.

Peraeon

Cx 1 smooth, length> width; anterior margin smooth, anterodistal corner somewhat lengthened, facial setae absent, inferior margin smooth.

Gn 1 basis somewhat inflated, smooth; ischium smooth; carpus basis more than half as long as propodus, distal part linear, narrow, about 7-9 x longer than wide (width very different); propodus straight, about 5 x as long as wide, palm smooth; dactylus smooth, reaching more than 1/3 propodus length.

Cx 2 about as wide as long, in the shape of a parallelogram, width similar to Cx 3, distally smooth; anterior margin scarcely excavate, anterodistal corner acutely lengthened, inferior and posterior margin straight, facial setae absent.

Gn 2 basis not inflated, on anterior margin some setae; carpus nearly reaching half propodus length, curved, distally rounded, with small incision, setose; propodus anterodistally without prolongation, with some setae, posterior margin with many low humps, palm convex, proximally near dactylus-end with weak blunt corner; facial setae medially and submedially present, but not abundant; dactylus curved, both margins smooth, bare, reaching somewhat more than half of propodus length.

Cx 3 length subequal to width, rounded, anterior and posterior margin straight, quadrangular, smooth, facial setae absent.

Cx 4 length shorter then width, smooth, bare, anterior margin distally excavate, anterodistal corner acutely pointed and lengthened, posterior margin clearly shorter than anterior one, rounded, facial setae absent.

P 3, 4 basis slender, width subequal to merus; dactylus reaching nearly half length of propodus, posterior margins smooth.

Cx 5-7 facial setae absent.

P 5-7 similar, bases l:w ratio about 1.5, margins smooth. Merus with posterodistal corner scarcely lengthened and not widened.

Pleon

Ep 1-3 bare. Ep 2 posterodistal corner somewhat upturned, rounded; Ep 3 posteroventral corner blunt, rectangular.

Uropods: U 2 with unequal rami, the shorter one shorter than peduncle. U 3 unknown.

Telson ratio l:w unknown.

Remarks

Until now we know only one representative of this new species, but the peculiar shape of Cx 2 and Cx 4 makes it easy to recognize it within the Antarctic and sub-Antarctic species. Within the hitherto known Leucothoe species L. lilljeborgi (Boeck, 1861) as well as L. ayrtonia Bellan-Santini, 1997 have a similar Cx 4 with a pointed anterodistal corner but rounded Cx 2, while L. angusticoxa (Ledoyer, 1972), described as “ Leucothopsis n. gen. ”, has Cx 2 pointed and Cx 4 rounded.

Distribution

East Antarctic, off Queen Maud Land, Breidbay (70°S, 24°E).

Depth range

200 m.