Paramoguai kavieng Ahyong, 2014, sp. nov.
Creators: name: Ahyong, Shane T.
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Camptandriidae
Paramoguai
Paramoguai kavieng

description: Paramoguai kavieng sp. nov.
(Figs 1–3)
Type material. Holotype: MNHN IU- 2014-2542, male (cl 3.1 mm, cw 2.6 mm), between Manne and Baudison islands, 02°42.694'S, 150°41.651'E, 12 m, fine mud, stn KS27, coll. S. Schiaparelli & E. Vassard, 10 June 2014. Paratypes: MNHN IU- 2014-2590, ovigerous female (cl 5.0 mm, cw 4.6 mm), entrance to Tome river system, 02°41.586'S, 150°51.354'E, 1–2 m, muddy rocky bottom, stn KD55, coll. M. Claydon et al., 19 June 2014; MNHN IU- 2014-2894, 2 ovigerous females (cl 4.6 mm, cw 4.2 mm; cl 5.2 mm, cw 4.4 mm), E of Cape Sueusat, 02°38.473'S, 150°48.550'E, 7 m, mud & silt, stn KD68, coll. C. Siwisika et al., 22 June 2014; AM P96596, 1 spent female (cl 5.4 mm, cw 4.9 mm), around Pochol Island, 02°34.007'S, 150°33.694'E, 6–7 m, sand & broken shells, stn KD62, coll. C. Siwisika et al., 20 June 2014; AM P96597, 1 male (cl 3.6 mm, cw 3.0 mm), SW of Bangatan Island, 02°39.122'S, 150°34.181'E, 1–2 m, sand, seagrass, broken shells, stn KD66, coll. C. Siwisika et al., 22 June 2014; MNHN IU- 2014-2715, 1 ovigerous female (cl 4.5 mm, cw 4.0 mm), E of Cape Sueusat, 02°38.473'S, 150°48.550'E, 7 m, mud & silt, stn KD68, coll. C. Siwisika et al., 22 June 2014.
Diagnosis. Carapace anterolateral margins distinctly constricted behind outer orbital tooth. Posterior branchial surface without dorsolateral ridge or ornamentation. Rounded tooth at anterolateral corner of buccal cavity. Female telson 3.3 times wider than long. Male gonopod 1 with recurved distal portion lying close to proximal portion; branches of bifurcated distal portion subparallel, mesial branch distally spiralled, lateral blade-like branch with distal spines, base of bifurcation without projecting process.
Description. Carapace subcircular to pyriform (Fig. 1 A, 2A, 3); 1.21–1.22 times longer than broad (male), 1.09–1.17 (female); lateral margins rounded, distinctly granular, in dorsal view lateral to anterolateral margins; posterior margin granular, gently convex to almost straight, posterolateral corners each with prominent, blunt, granular projection. Dorsal surface uneven, pitted, with scattered individual and groups of short, dark red-brown setae lying against cuticle, surfaces otherwise almost glabrous. Low, blunt, transverse epigastric crista, sometimes medially divided. Mesogastric protuberance prominent, irregular, surfaces eroded, with pair of low granular tubercles anteriorly. Cardiac protuberance prominent, irregular, surfaces eroded, dorsally with pair of low granular tubercles. Intestinal region with narrow median protuberance forming inverted Y-shape, branches of Y leading towards marginal posterolateral projections; surfaces eroded, pitted. Hepatic region depressed, with low granular tubercle. Outer orbital tooth prominent, apices acute, directed laterally, margins granular. Anterolateral margins distinctly constricted behind outer orbital tooth, margins unarmed but with row of irregular, granular, coalesced tubercles reaching posteriorly to level of cardiac region, merging with irregular, curved, granular, tubercular ridge extending onto mesobranchial surface. Posterior branchial surface pitted, flattened, without dorsolateral ridge or ornamentation.
Front prominent, thickened, margins granular, surfaces pitted, medially sulcate, bilobed in dorsal view, lobes rounded; supraorbital eave weakly swollen, margins granular. Infraorbital margin (Fig. 1 B, C) with blunt, inconspicuous, granular mesial tooth; laterally fused with suborbital crista forming small anteriorly directed lobe and large, flattened, triangular plate bearing, shallow non-granular anterior concavity forming “cup”, apex directed anterolaterally, partially visible in dorsal view. Eyestalk longer than cornea, slightly bent at midlength.
Epistome unarmed, buccal margin medially emarginated, bilobed, each lobe broad, rounded (Fig. 1 B); anterolateral corners of buccal cavity with rounded, granular lobe. Antennular fossae diagonal, antennules folding diagonally. Antennal peduncle with 3 free articles; fused basal articles granular; flagellum very slender, hair-like.
Sternites pitted, sparsely setose, glabrous. Female gonopores (Fig. 2 D) positioned almost medially, vulva hood-like, orifices directed transversely.
Abdominal somites marginally setose, external surface distinctly pitted glabrous. Male abdomen (Fig. 1 G) with somites 2–5 immovably fused; somite demarcation faintly visible at 2/3, 3/4; somites 4/5 with demarcation only visible laterally; somite 5 subtrapezoidal, distinctly constricted proximally, partially exposing gonopods when abdomen “closed”; somite 6 trapezoidal, widest proximally, shorter than somite 5; telson longer than wide, apex rounded.
Female abdomen (Fig. 2 B) with somites 3–5 fused; somite 2 with transverse median and lateral ridges; somite 3/4 demarcation indicated by low median and lateral transverse ridges; faint trace of somite 4/5 demarcation; telson evenly rounded, width 3.3 times length.
Maxilliped 3 rectangular (Fig. 1 D). Ischium and merus fused, suture present only along mesial one-third; surface distinctly pitted, eroded; distolateral and distomesial margins rounded, not produced. Carpus triangular. Dactylus slender, filiform. Exopod tapering distally, reaching distal outer angle of merus; flagellum present.
Chelipeds (pereopod 1) equal, slender, subcylindrical, sparsely setose, shorter than pereopod 2 (Fig. 1 E). Dactylus longer than palm, occlusal margins thin, blade-like, without teeth, apices incurved.
Ambulatory legs (pereopods 2–5) short, slender (Fig. 1 A, F, 2C); relative lengths pereopod 3>4>2>5; surfaces with groups of short, dark, red-brown setae giving slightly banded appearance in addition to long, fine setae along extensor and flexor margins. Pereopods 2–5 proportionally longer, more slender in males than females. Pereopod 4 merus in males slightly longer than half carapace length (length: height ratio about 4); in females slightly shorter than half carapace length (length: height ratio about 3). Merus flexor margin shallowly concave; extensor margin slightly convex (pereopod 2) or obtusely angled at proximal one-third (pereopods 3–5); distal flexor margin with prominent, rounded projecting lobe (pereopods 2–4) or short rounded lobe (pereopod 5). Carpus and propodus unarmed. Dactylus styliform, slightly curved, as long as or longer than propodus.
Male gonopod 1 (Fig. 1 H) strongly geniculated, tightly bent with recurved distal portion almost against proximal portion; recurved portion deeply bifurcated forming two slender subparallel branches. Mesial branch smooth, unarmed, distally spiralled, tapering to spiniform apex. Lateral branch distally flattened, blade-like, with 8 recurved spines. Male gonopod 2 (Fig. 1 I) about one-fourth length of gonopod 1, slender, apex rounded, slightly expanded.
Etymology. Named after the general area from which the type material was collected, Kavieng, New Ireland Province, Papua New Guinea; used as a noun in apposition.
Remarks. Paramoguai kavieng sp. nov. closely resembles its only congener, P. pyriforme (Naruse, 2005) from the Ryukyu Islands, Japan, differing chiefly in carapace ornamentation and male gonopod morphology. The carapace of P. kavieng differs from that of P. pyriforme in having a distinct constriction behind the outer-orbital tooth (only slightly concave in P. pyrif or me) and in lacking the irregular ridge that starts anteriorly below the anterolateral margin and runs along the upper branchial margins, terminating at the posterolateral tubercle (which is much more prominent in the new species). Paramoguai kavieng also differs from P. pyriforme in having a rounded instead of acutely triangular tooth on the anterolateral corner of the buccal cavity, and a proportionally wider female telson (width 3.3 times length; 2.8 in P. pyriforme). The male gonopod 1 exhibits the most distinctive differences between P. kavieng and P. pyriforme. In P. kavieng, the recurved, bifurcated distal portion of the gonopod lies close to (almost against) the proximal portion, with the branches of the bifurcation subparallel (Fig. 1 H). In contrast, the recurved portion of gonopod 1 in P. pyriforme diverges strongly from the proximal portion, and the branches of the bifurcation are themselves distinctly divergent (Kishino et al. 2014). In P. kavieng (Fig. 1 H), the mesial branch of the recurved portion is distally spiralled (straight in P. pyriforme), the blade-like lateral branch is armed with small spines (smooth in P. pyriforme), and there is no digitiform process projecting from the base of the bifurcation of the branches (present in P. pyriforme).
The postorbital portion of the carapace is subcircular in both sexes of P. kavieng. Aside from primary sexual differences, however, mature female P. kavieng differ from males in the proportionally wider, more laterally expanded carapace, proportionally shorter fronto-orbital area, proportionally shorter, more slender pereopods 2–5 (as measured by meral length and proportions), and a larger maximum body size. Paramoguai pyriforme exhibits similar sexual dimorphism (Kishino et al. 2014).
Colour in life. Drab grey-brown with scattered tufts of dark red-brown setae (Fig. 3 A–C). The gastrofrontal area and posterior half of the carapace in one specimen was solid white (MNHN IU- 2014-2715; Fig. 3 D).
Habitat. Paramoguai kavieng was collected in shallow water (1–2 to 12 m depth) on substrates of sand, mud, silt, shell and seagrass. One specimen (MNHN IU- 2014-2590) was taken near a river mouth. The remainder, however, were taken from areas away from significant freshwater input suggesting that the ecology of Paramoguai kavieng may differ from that of P. pyriforme and species of Moguai, all of which occur intertidally in estuarine and brackish habitats (Tan & Ng 1999; Naruse 2005).
Distribution. Presently known only from Papua New Guinea from localities in the vicinity of Kavieng, New Ireland Province.
description: Published as part of Ahyong, Shane T., 2014, Paramoguai kavieng, a new genus and species of camptandriid crab from Papua New Guinea (Crustacea: Brachyura), pp. 578-584 in Zootaxa 3856 (4) on pages 579-583, DOI: 10.11646/zootaxa.3856.4.6, http://zenodo.org/record/231590