Linguimaera pirloti, Krapp-Schickel, 2003

Krapp-Schickel, T., 2003, Linguimaera Pirlot, 1936 (Crustacea, Amphipoda, Melitidae), a valid genus, Memoirs of Museum Victoria 60 (2), pp. 257-283 : 261

Linguimaera pirloti sp. nov.

Figure 2

Linguimaera othonides . — Pirlot, 1936: 309–311, fig. 132.

Material examined. Holotype. Sulawesi, Sailus ketjil, Iles Paternoster , 27 m depth, corals and sand, 30, 31 Mar 1899 ( Siboga Expedition stn 37), ZMA Amph. 204584 (1 male, 7.1mm on 2 slides).

Paratypes. Détroit de Molo , 54–90 m, sand, 19 Apr 1899 ( Siboga Expedition stn 51) ZMA Amph. 204585 (4 females, all on slides; 11 inadults in alcohol). 4°20´S, 122°58´E, sand and shells, 20 Sep 1899, 75–94 m ( Siboga Expedition stn 204), ZMA Amph. 204586 (2 males, 1 adult female, partly on slides) .

Diagnosis. Female gnathopod 1 propodus ratio of length: width = 3, in male = 2; palm not defined, posterior margin regular; palmar corner proximally followed by shallow excavation. Gnathopod 2 in both sexes similar in shape, but asymmetrical; in female palmar excavations deeper. Pereopod 7 basis ratio of length: width = 1.25. Telson with 2 or 3 distal robust setae, maximum lengths half length of telson.

Description. Adult male and female 6–7.1 mm.

Head: lateral cephalic sinus anteroventral corner blunt, nearly right-angled. Eyes with upper half narrower. Coxae 1–4 with small notch posterodistally.

Antenna 1 peduncle with 1 robust seta on article 1 distally; peduncle article 1 subequal article 2; article 3 about one third of article 1; accessory flagellum of 3–4 articles; antenna 2 slen- der, gland cone short, peduncle reaching end of antenna 1 peduncle; article 4 longer than article 5, flagellum as long as article 5, of about 12–14 articles.

Mandibular palp article 1 longer than wide; ratio of article 2: article 1 = 3.6; article 2: article 3 = 1.3; article 2 with 4 long setae but no groups of setae along margin; article 3 with 8 long setae. Mandibular incisor, lacinia mobilis and molar with medium sized blunt teeth. Molar medium Labium with rounded inner lobes, outer ones densely setose. Maxilla 1 unknown. Maxilla 2 outer plate wider than inner plate, outer plate 8 robust setae only distally, no setae marginally. Maxilliped unknown.

Gnathopod 1 weakly sexually dimorphic. Coxa 1 anteriorly acutely produced. Basis ratio length: width = 3, anterior margin with 3 long setae, posteriorly more and longer ones; merus posteroventrally with acute tooth; carpus with nearly parallel margins, length to width about 2.5, with stiff marginal and submarginal robust setae; propodus in female slim, narrower than carpus, ratio length: width= 2.5–3.0, in male wider, twice as long as wide, in both palm not defined.

Gnathopod 2 of female slightly asymmetrical in size, similar in shape. Coxa 2 longer than wide, basis with few short setae on anterior margin, many very long ones on posterior margin; merus posterodistally with acute tooth; carpus posteroventral corner rounded; length ratio carpus: propodus = 0.8, about same width; propodus slender, ratio length: width = 2.5–3.0, palm concave, weakly defined by corner; 1 subdistal prominent robust seta on the inner surface next to the palmar corner, 2 smaller ones along the palm. Gnathopod 2 of male dimorphic both in size and shape: the smaller is as described for the female, the other has a longer, less excavated palm. Dactylus not much curved.

Pereopods spinose, propodus longer than merus, carpus shorter, length of basis: propodus = 1.3; basis posterior margin serrate, posterodistal corner somewhat lengthened. Dactyli forming a “chela” with their nail and the stiff, towards the dactylus bent robust seta on inner margin.

Epimeral plates 1, 2 posteroventral corners acute, followed by a shallow short sinus ending with a blunt tooth. Epimeral plate 3 with up to 9 small teeth on posterior margin, in adult males many irregular teeth, in juvenile specimens less; ventral margin smooth.

Uropod 2 the shortest, uropod 3 extending much more than uropod 1; uropod 1 peduncle longer than rami, 1 sub-basofacial strong curved robust seta in about one third of length on outer margin, 1 very long robust seta subdistally; inner ramus longer than outer one. Uropod 2 distally with 2 longer and some shorter robust setae. Uropod 3 ratio peduncle: rami less than 0.5, rami subequal, outer somewhat narrower than inner one; 1 article; both distally tapering, scarcely truncate, with 2–3 distal robust setae, marginal ones on outer ramus in 3–4 groups, on inner one many short single ones.

Telson, inner side shorter and outer corner acutely prominent; in the excavation 2–3 strong robust setae (0.2–0.5 of telson length).

Etymology. Dedicated to J.M. Pirlot.

Distribution. Sulawesi, Indonesia; coral rubble, shells, sand, 27– 94 m.

Remarks. The “disproportionate” insertion between propodus and carpus, which Barnard (1972a: 126) stressed for this species flock, and which leads to a deeper “gap” dorsally in other species, is here very scarcely visible.

Figures

Figure 2. Linguimaera pirloti sp. nov., male, female (Sri Lanka). Gn2 female, Us, U3 in scale x = 0.5 mm; Gn 1,2 male in scale x = 0.25 mm; P7 in scale y = 1 mm; Md, Mx2 in scale x = 0.2 mm.