Lyphira chomel, Rahayu & Ng, 2024

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, Zootaxa 5476 (1), pp. 358-392 : 368-376

publication ID	https://doi.org/ 10.11646/zootaxa.5476.1.29
publication LSID	lsid:zoobank.org:pub:DD4EA1FE-A0BE-4BA4-9AD3-E460B131C518
DOI	https://doi.org/10.5281/zenodo.12746334
persistent identifier	https://treatment.plazi.org/id/03DD87DA-FFB4-1256-28EE-FDE9875B1D99
treatment provided by	Plazi
scientific name	Lyphira chomel
status	sp. nov.

Treatment

Lyphira chomel n. sp.

( Figs. 3E‒G View FIGURE 3 , 6C View FIGURE 6 , 7E View FIGURE 7 , 9C View FIGURE 9 , 10D View FIGURE 10 , 11D View FIGURE 11 , 12B, C View FIGURE 12 , 13D, E View FIGURE 13 , 14C View FIGURE 14 , 15E View FIGURE 15 , 16D View FIGURE 16 , 17M‒R View FIGURE 17 , 21C View FIGURE 21 )

Lyphira heterograna View in CoL . — Galil, 2009: 300 View Cited Treatment (part), figs. 12B, 14. (Not Philyra heterograna Ortmann, 1892 View in CoL )

Type material. Holotype: male (10.1 × 10.3 mm), ZRC 1999.0798 View Materials , off Pontian , western Johor, Malaysia, coll. dredge, T.H.T. Tan & D. Vandenspiegel, 1992 . Paratypes: 1 ovigerous female (9.6 × 9.7 mm), ZRC 1985.0099 View Materials , station Sig 3/11, on muddy substrate, off Bedok, Singapore, 16.5 m (9 fathoms), coll. dredge, D.S. Johnson, 1960s; 4 males (8.8 × 9.0 mm, 10.4 × 10.3 mm, 10.5 × 10.6 mm, 12.6 × 12.8 mm) , 1 female (11.2 × 11.2 mm), 1 partially crushed female (13.5 × 13.4 mm), ZRC 1985.0091 View Materials – 0096 View Materials , station B77, on mud, off Bedok , Singapore, 16.5 m (9 fathoms), coll. dredge, D.S. Johnson, 1960s ; 1 ovigerous female (11.4 × 11.1 mm) ZRC 1985.0098 View Materials , station B78, mud substrate, off Tanjung Stapa , Pengerang, southeastern Johor, Peninsular Malaysia, 1°21'00.0"N 104°08'00.0"E, 31 m (17 fathoms), coll. dredge, D.S. Johnson, 1960s; GoogleMaps 3 males (12.5 × 11.3 mm, 12.7 × 12.7 mm, 13.0 × 12.9 mm) , 2 female (11.6 × 11.4 mm), NHM 1900.10.22.340–343, on mud, Malacca, Peninsular Malaysia, 1–2 m, coll. F. P. Bedford & W.F. Lanchester, 1899–1900.

Diagnosis. Carapace approximately as broad as long or slightly longer than broad, dorsal surface of carapace covered with closely spaced minute granules, hepatic and intestinal regions with larger, more prominent granules ( Figs. 3E‒G View FIGURE 3 , 6C View FIGURE 6 ). Frontal margin granulated, postfrontal lobe slightly convex ( Figs. 11D View FIGURE 11 , 13D, E View FIGURE 13 ). Endostomial spine absent ( Figs. 13D, E View FIGURE 13 , 14C View FIGURE 14 ). Lateral and posterolateral margin of carapace with row of small granules interspersed by larger granules; posterior carapace margin gently convex with row of larger granules ( Figs. 3E‒F View FIGURE 3 , 10D View FIGURE 10 ). Third maxilliped exopod 2.5 times as long as broad, slightly narrower than basal part of endopod, forming petaliform structure with convex outer margin, endopod with completely fused basis-ischium, longer than merus, with shallow submarginal sulcus near inner margin ( Figs. 11D View FIGURE 11 , 17M View FIGURE 17 ). Chelipeds subequal; merus covered by large rounded granules ( Figs. 3E View FIGURE 3 , 6C View FIGURE 6 , 9C View FIGURE 9 ); surfaces of carpus and propodus covered by closely spaced small granules; chela slender, fingers longer than length of palm, surface with longitudinal sulcus flanked by row of granules; pollex slightly bent, cutting edge lined with denticles, large tooth subproximally; dactylus 1.5 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. 15E View FIGURE 15 ). P2–P5 slender, long; merus distinctly longer than carpus and propodus; dactylus longer than propodus, lanceolate, terminating in corneous tips ( Figs. 3E View FIGURE 3 ); fourth leg shortest with merus 5.6 times as long as broad, margins almost smooth, lined barely with small granules ( Fig. 16D View FIGURE 16 ). Thoracic sternites transversely narrow, surface granulated, larger granules laterally ( Fig. 7E View FIGURE 7 ). Sternopleonal cavity deep, reaching to proximal distance between fused thoracic sternites 1–3. Pleon narrow, somites 2–6 fused, somite 6 longitudinally subrectangular, surface with one low granule subdistally, lateral margins gently convex; telson triangular ( Figs. 7E View FIGURE 7 , 17N View FIGURE 17 ). G1 elongate, slender, same size from proximal to distal area; distal process gently curved, with blunt tip ( Fig. 17O‒R View FIGURE 17 ). Female pleon broad, convex, smooth, somites 2‒6 fused, suture between somites 2 and 3; telson as long as its basal width ( Fig. 9C View FIGURE 9 ); vulvae positioned closer to median part of sternite 6, each opening relatively broad, ovate, without opercular cover ( Fig. 21C View FIGURE 21 ).

Colour. Not known.

Etymology. The named is derived from the Malay word for small and cute, “chomel ”. The name is used as a Latin noun in apposition.

Remarks. Lyphira chomel n. sp. is a very distinct species. Its short and poorly developed endostomial spines, and the relatively narrow third maxilliped exopod allies it with L. heterograna s. str. and L. acutidens , but L. chomel n. sp. can immediately be distinguished by its prominently slenderer and elongate ambulatory meri ( Fig. 16D View FIGURE 16 ) and the granules on the merus of the cheliped being evenly spread out, reaching to the distal surfaces ( Fig. 3E View FIGURE 3 ). In L. heterograna s. str. and L. acutidens , the ambulatory meri are distinctly shorter and stouter ( Fig. 16A‒C View FIGURE 16 ) and the distal surfaces of the merus of the cheliped are relatively smoother with only scattered granules present ( Fig. 3A‒D View FIGURE 3 ). The G1s of L. chomel n. sp. and L. heterograna s. str., however, are similar, with the apical process longer and gently curved ( Fig. 17C‒F, O‒R View FIGURE 17 ). On the basis of published data, L. chomel n. sp. is also the smallest species, with male specimens as small as 10 mm in carapace width already mature and females of a similar size already ovigerous. Lyphira heterograna s. str. and L. acutidens both reach larger sizes (smallest adult female averages 12 mm carapace width) (cf. Chen 1987; Chen & Sun 2002; present data).

Galil’s (2009: 300) stated she examined several specimens of “ L. heterograna ” from Peninsular Malaysia: four males and two females from Malacca (NHM 1900.10.22.340–345) and one male from Pontian (ZRC 1999.0798). Galil (2009: figs. 12B, 14) figured a male specimen (15.1 mm carapace length, NHM 1900.10.22.340–345) (incorrectly stated as from Indonesia). Her figures agree very well with the holotype male of L. chomel n. sp. (which is here based on her Pontian male), including the pattern of granules on the merus of the cheliped, relatively slenderer P2–P5 and structure of the G1.

In Singapore, L. chomel n. sp. is sympatric with L. linda n. sp., but they appear to have slightly different habitats. Although both are intertidal to subtidal, L. chomel n. sp. appears to prefer more muddy substrates, whereas L. linda n. sp. likes area which are sandier.

Type locality. Pontian , Peninsular Malaysia .

Distribution. Southern Peninsular Malaysia and Singapore.