Lyphira ngankee Rahayu & Ng, 2024, n. sp.
Creators: name: Rahayu, Dwi Listyo
name: Ng, Peter K. L.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Leucosiidae
Lyphira
Lyphira ngankee

description: Lyphira ngankee n. sp.
(Figs. 1E–J, 5A, B, 6D, 8A, 9D, 10E, 11E, 13F, G, 14D, 15F, 16E, 18A‒E, 20A‒D, 21D)
Philyra tuberculosa.— Shen 1931: 185, text figs. 1, 2, 4; Shen 1932: text fig. 11e, f. (not Philyra tuberculosa Stimpson, 1858 = Philyra carinata Bell, 1855).
Philyra globosa.— Shen 1940: 216 (not Cancer globosus Fabricius, 1793 = Cancer globus Fabricius, 1775).
Philyra cf. laminata. — Hill 1982: 199, pl. 3C. (not Philyra laminata Doflein, 1904 = Heteronucia laminata (Doflein, 1904)).
Philyra heterograna.— Blackmore & Rainbow 2000: appendix 1. (not Philyra heterograna Ortmann, 1892).
Lyphira heterograna.— Wong et al. 2021: 20, fig. 30a–c, pl. 6C. (not Philyra heterograna Ortmann, 1892).
Type material. Holotype: male (20.8 × 21.8 mm), ZRC 1999.0456, Nanao Island, Gianjing fish port, Guangdong, coll. N.K. Ng & Y. Cai, 12 November 1998. Paratypes: 5 males (largest 20.7 × 21.3 mm), 2 females (larger 18.8 × 18.8 mm), ZRC 2022.0628, station W2, southeast of Lantau Island, Hong Kong, 22°11.264'N 113°51.358'E – 22°12.926'N 113°54.570'E, 10.0–11.6 m, coll. Hong Kong University Trawl, 27 August 2012.
Diagnosis. Carapace approximately as broad as long, rounded (Figs. 1E, 5A, B, 6D); dorsal surface of carapace covered with closely spaced minute granules, hepatic, branchial and intestinal regions with slightly larger, more prominent granules;. Frontal margin granulated; postfrontal lobe slightly convex with slight concave medially (Figs. 11E). Endostomial spine strong, produced, visible from dorsal view (Figs. 1F, 13F, G, 14D). Lateral margin of carapace with row of small granules interspersed by larger granule; posterior margin gently convex (Figs. 5A, B, 6D). Posterior carapace margin with row of granules, slightly larger granule medially and on each posterolateral corner, with margin between them gently convex (Figs. 10E). Third maxilliped exopod 2 times as long as broad, wider than basal part of endopod, forming petaliform structure with strongly convex outer margin, with submarginal row of low to very low granules along inner margin; endopod with completely fused basis-ischium, distinctly longer than merus, with shallow submarginal sulcus near inner margin (Figs. 1G, 11E, 18A). Chelipeds subequal; merus, carpus and chela surfaces smooth or covered with low, small rounded granules (Figs. 5A, B, 6D); merus subcylindrical, symmetrical along entire length, surface granulated, large granules on proximal area and along margins, minutes granules distally; carpus smooth, unarmed; chela stout, palm surface smooth, upper and lower margins with row of granules, longitudinal row of relatively large granules on lower outer surface of palm; pollex slightly bent, cutting edge lined with denticles; dactylus 1.4 times as long as palm along upper margin, row of small granules on upper margin, cutting edge with median large tooth lined with denticles, remaining of edge with small denticles (Fig. 15F). P2–P5 slender, short; merus distinctly longer than carpus and propodus, dactylus longer than propodus, lanceolate, terminating in corneous tips (Figs. 5A, B, 6D); fourth leg shortest with merus 3.8 times as long as broad, margin lined with small granules, more prominent on ventral margin (Fig. 16E). Thoracic sternites transversely narrow, surface finely granulated, larger granules laterally (Fig. 8A). Male sternopleonal cavity deep, reaching to proximal distance between fused thoracic sternites 1–3. Male pleon narrow, slender, long; somite 1 longitudinally narrow, wide; somites 2–6 fused, forming elongate trapezoidal plate, shallow suture just visible between somites 5 and 6, surface smooth; somite 6 longitudinally subrectangular, surface with one granule submedially, lateral margins gently convex; telson triangular, longer than wide (Figs. 1H, 8A, 18B). G1 elongate, slender, slightly dilated distally; apical process short, bent at an angle of 60º along the longitudinal axis, with blunt tip (Figs. 1J, 18C‒E, 20A‒D). Female sternopleonal cavity reaches distal part of sternite 1; female pleon broad, convex, smooth, somites 2‒6 fused, suture between somites 2 and 3; telson shorter than its basal width (Figs. 1I, 9D); vulvae spaced apart on sternite 6, each opening weakly crescent-shaped, relatively short, without opercular cover (Fig. 21D).
Colour. Light grey on dorsal surfaces.
Etymology. The species is named after the late Ng Ngan Kee, an esteemed colleague and very good friend, departed all too soon in 2022. She was a leader in varunid systematics and also an avid educator and field scientist; the holotype specimen was actually collected by her during one of her many forays throughout Asia. The name is used as a noun in apposition.
Remarks. The difference in the shape of carapace, the P5 merus and the G1 between L. ngankee n. sp. and L. heterograna are well defined. In L. ngankee n. sp., the carapace is relatively more rounded and more convex, the endostomial spine is strongly produced, clearly visible from dorsal view, the P5 merus leg is short, only 3.8 times as long as broad, the exopod of the third maxilliped is broad, strongly convex, and the apical process of G1 short, broad and bent at an angle of 60° along the longitudinal axis (Figs. 1E–G, J, 5A, B, 6D, 13 F, G, 14D, 16E, 18A, C‒E). Lyphira heterograna s. str. has the carapace usually slightly longer than broad, the endostomial spines are short, the P5 merus is relatively longer 4.3 times as long as broad, the exopod of the third maxilliped is narrower, not as convex, and the G1 with apical process long, very slightly bent (Figs. 1A–C, 2A, B, 3A, B, 13A, 16A, B, 17A, C‒F).
Lyphira ngankee n. sp. is perhaps most similar to L. linda n. sp., sharing the characters of a strong endostomial spine and a wide exopod of the third maxilliped. The differences between the two are discussed under the remarks for the latter species.
Lyphira ngankee n. sp. and L. linda n. sp. are superficially similar to L. ovata, described from one male specimen from Sri Lanka. Lyphira ovata, however, can easily be separated from these two species in having the dorsal carapace surface more densely covered with granules and the anterolateral margin is almost straight in dorsal view (cf. Galil 2009: fig. 16A). In L. ngankee n. sp. and L. linda n. sp., there are distinctly fewer granules on the dorsal carapace surface and the anterolateral margin is distinctly convex in dorsal view (Figs. 4, 5A, B). Galil (2009: 303) did not figure the G1, only describing it as “with apical process digitate, squat”, suggesting it is similar to the condition observed for L. ngankee n. sp. and L. linda n. sp., in which the distal process is short and not prominently elongate (Figs.18D, E, O, P, 20A‒D, E‒M).
The wide exopod of the third maxilliped of L. ngankee n. sp. similar to those of L. georgei and L. perplexa, but differences can be seen in the more rounded carapace in L. ngankee n. sp. (Figs. 1E, 5A, B, 6D) (longer than broad in L. georgei and L. perplexa), the presence of strong endostomial spines in L. ngankee (Figs. 13F, G, 14D) (absent in L. georgei and L. perplexa), and the P5 merus is proportionately shorter in L. ngankee, 3.8 times as long as broad (Fig. 16E) (proportionately longer, being 4 times in L. perplexa but much shorter in L. georgei, 3.2 times as long as broad) (cf. Galil 2009: fig. 17A, B; Trivedi et al. 2016: figs. 1a, b). Their colours in life are also different, with L. ngankee n. sp. being greyish white overall while the carapace of L. georgei and L. perplexa are orange to purple (cf. Trivedi et al. 2016; unpublished data).
Type locality. Nanao Island, Guangdong, China.
Distribution. Nanao Island, Guangdong, and Hong Kong.
description: Published as part of Rahayu, Dwi Listyo & Ng, Peter K. L., 2024, On the genus Lyphira Galil, 2009 (Crustacea: Brachyura: Leucosiidae), with descriptions of four new species from the West Pacific, pp. 358-392 in Zootaxa 5476 (1) on pages 376-377, DOI: 10.11646/zootaxa.5476.1.29, http://zenodo.org/record/12681921