Monomia lucida Koch & Ďuriš, 2018

Huang, Yu-Hsuan & Shih, Hsi-Te, 2021, Chthonius rhodochelatus Hadzi 1933, Zoological Studies 60 (60), pp. 1-45 : 18-21

Monomia lucida Koch & Ďuriš, 2018 ( Figs. 3G , 11 )

Portunus argentatus – Stephenson and Rees 1967: 16 (part), fig. 2a, b ( Philippines); Cariaso and Garcia 1986: 209, fig. 23 ( Philippines). (not Neptunus argentata A. Milne-Edwards, 1861 ).

Monomia argentata – Chertoprud et al. 2012: 313 (part), pl. 51F ( Vietnam). (not Neptunus argentata A. Milne-Edwards, 1861 ).

Monomia lucida Koch & Ďuriš, 2018: 569 , figs. 1–3 (type locality: Nhatrang, Vietnam); Sasaki 2019: 9052 (list).

Material examined: Taiwan: 3 males (47.1–51.1 × 27.4–30.6 mm), 3 ovig. females (46.8–49.7 × 26.4–28.7 mm) (NCHUZOOL 16510), Dalinpu, Siaogang, Kaohsiung, Aug. 2001; 4 males (30.8–53.5 × 17.3–30.2 mm) (NCHUZOOL 16533), Erzihliao Fishing Port, Kaohsiung, coll. YH Huang, 21 Jan. 2020; 2 males (21.6–34.6 × 11.9–19.3 mm), 1 female (32.0 × 17.1 mm) (NCHUZOOL 16535), Zuoying, Kaohsiung, 2 Oct. 2001; 1 male (59.9 × 33.7 mm), 1 ovig. female (48.3 × 27.3 mm) (NCHUZOOL 16536), Erzihliao Fishing Port, Kaohsiung, coll. YH Huang, 20 May 2016; 1 male (54.8 × 30.7 mm) (NCHUZOOL 16538), Erzihliao Fishing Port, Kaohsiung, coll. YH Huang, 8 Jul. 2018.

Comparative material: Monomia argentata : 1 male (20.7 × 11.0 mm) (NCHUZOOL 16543), Zuoying, Kaohsiung, Taiwan, Jun. 2001; 4 males (31.2–37.7 × 16.1–21.3 mm) (NCHUZOOL 16544), Magong Fishing Port, Penghu, Taiwan, coll. YH Huang et al., 17 Jan. 2020.

Diagnosis: Carapace transversely hexagonal, 1.7– 1.8 times broader than long, surface densely pilose, with granular patches. All carapace ridges absent, except epibranchial regions with a pair of faintly granulated ridges ( Fig. 11A ). Front with 4 rounded teeth, median 2 smaller than lateral, sulcus between median teeth continuing ventrally to triangular projection. Epistome with median tooth projecting beyond front. Supraorbital margins with 2 notches, lateral notch with tooth-like elevation before anterolateral tooth 1. Inner supraorbital angle tooth-like, with ventromesial ledge. Infraorbital

10 mm

margins with deep lateral notch. Anterolateral margins with 9 teeth, tooth 9 largest and projecting laterally, teeth 2–4 smallest ( Fig. 11A ). Basal antennal segment with lateral blunt lobe entering orbital cavity. Chelipedal merus with 4 spines on inner margin, 2 on outer margin; carpus with spine each on inner and outer margins; palm with 2 spines on dorsal surface. P5 with merus granulated on inner margin distal part. Maxillipeds 3 with merus longer than broad, anteroexternal angle strongly expanding to a prominent auriculiform structure. Male pleon with pleomere 6 longer than broad, lateral margins subparallel and slightly converging anteriorly. G1 with distal half slender and bent laterally about 90°, tip with spines ( Fig. 11B–E ).

Coloration: Carapace and chelipeds tannish with patches of white and brown granules. P5 with a large black spot on dactylus ( Fig. 3G ).

Distribution: Philippines; Taiwan; Vietnam (Nhatrang Bay); India (northwestern) ( Cariaso and Garcia 1986; Koch and Ďuriš 2018; this study).

Ecological notes: Specimens were caught by trawling and collected from a fishing port.

Remarks: Monomia lucida Koch & Ďuriš, 2018 is similar to M. argentata (A. Milne-Edwards, 1861) in coloration and morphology ( Fig. 3G ; Koch et al. 2017: fig. 5; Koch and Ďuriš 2018: fig. 1). Biogeographically M. lucida was only distributed from Vietnam and northwestern India ( Koch and Ďuriš 2018), and M. argentata is distributed widely in the Indo-West Pacific ( Sasaki 2019). The specimens from Taiwan is consistent with M. lucida by the following characters: (1) lateral margins of male pleomere 6 subparallel in M. lucida ( Koch and Ďuriš 2018: fig. 2B) (vs. median part convex in M. argentata ; Koch et al. 2017: figs. 7B, 8A–D); (2) G1 with distal part slender, tip subtriangular in M. lucida ( Fig. 11B–E ; Koch and Ďuriš 2018: fig. 3A, B) (vs. distal part stout, tip blunt in M. argentata ; Koch et al. 2017: fig. 4); (3) female with long transverse ridges on both pleomeres 4 and 5 in M. lucida ( Koch and Ďuriš 2018: fig. 3C) (vs. with medium and short ridges on pleomeres 4 and 5 respectively in M. argentata ( Koch et al. 2017: fig. 8E).

Figures

Fig. 3. Species of the family Portunidae. A, Carupa ohashii Takeda, 1993, female (34.9 × 23.1 mm) (NCHUZOOL 16500), Dongsha I.; B, Lupocycloporus minutus (Shen, 1937), male (17.5 × 9.7 mm) (NCHUZOOL 16534), Zuoying, Kaohsiung; C, Lupocyclus inaequalis (Walker, 1887), male (21.6 × 16.3 mm) (NCHUZOOL 16551), Erzihliao Fishing Port, Kaohsiung; D, Lupocyclus tugelae Barnard, 1950, male (17.5 × 13.1 mm) (NCHUZOOL 16560), Erzihliao Fishing Port, Kaohsiung; E, Podophthalmus minabensis Sakai, 1961, male (25.2 × 14.9 mm) (NCHUZOOL 16499), Dalinpu, Siaogang, Kaohsiung; F, Monomia gladiator (Fabricius, 1798), male (53.0 × 31.2 mm) (NCHUZOOL 16506), Erzihliao Fishing Port, Kaohsiung; G, Monomia lucida Koch & Ďuriš, 2018, male (54.8 × 30.7 mm) (NCHUZOOL 16538), Erzihliao Fishing Port, Kaohsiung; H, Xiphonectes tuberculosus (A. Milne-Edwards, 1861), males (24.3 × 14.3 mm) (NCHUZOOL 16530), Zuoying, Kaohsiung.

Fig. 11. Monomia lucida Koch & Ďuriš, 2018.A, carapace, male (54.8 × 30.7 mm) (NCHUZOOL 16538); B–E, male (41.4 × 22.6 mm) (NCHUZOOL 16533), right G1; B, C, dorsal view; D, E, ventral view.