Rhopalomeris carnifex (Pocock, 1889)

Figs 2, 3

Glomeris carnifex Pocock, 1889: 290 (D). Type locality: Tenasserim.

Glomeris carnifex var. pallida Pocock, 1889: 290 (D). Type locality: Elphinstone Island.

Glomeris carnifex – Pocock 1890: 385 (R); Attems 1914: 138 (L); Hoffman 1980: 65 (M).

Glomeris carnifex var. pallida – Attems 1914: 138 (L); Silvestri 1917: 143 (D).

“ Glomeris ” bicolor [non Wood, 1865] – Verhoeff 1910: 241 (M); Silvestri 1917: 143 (M); Hoffman 1980: 65 (M).

Rhopalomeris carnifex – Silvestri 1917: 142 (D); Attems 1936: 194 (R); Enghoff 2005: 88 (R); Decker 2010: 24 (R); Golovatch et al. 2011: 6 (D); Golovatch and Semenyuk 2016: 411 (M, K); Likhitrakarn et al. 2017: 6 (L); Nguyen et al. 2019: 292 (M); 2021: 259 (M).

Rhopalomeris carnifex var. pallida – Silvestri 1917: 143 (D); Attems 1936: 194 (L).

Records in the literature.

Myanmar, south Tenasserim (Pocock 1889); Malwoon in Tenasserim (Pocock 1890); Elphinstone Island (Pocock 1889); Moulmein (Attems 1936); Taninthay Division, Tanintharyi Region, 9°56'20˝N, 98°32'22˝E, Thatay Kyun (= Pulo Ru, Ko Son) (Decker 2010). Thailand, Phuket Province, Salanga Island (= Phuket Island ) (Verhoeff 1906; Enghoff 2005); Mueang Phuket District, Ko Siray, 7°53'7˝N, 98°26'14˝E, 20–50 m a. s. l. (Decker 2010); Krabi Province, Krabi District, Nai Chong (Enghoff 2005); Ao Luk, 8°10'54˝N, 98°50'30˝E, 70 m ; Ban Khlong Jilat, 8°05'18˝N, 98°52'56˝E, 60 m a. s. l. ; near Saengphet Cave, 8°9'46˝N, 98°53'12˝E, 80 m ; Ko Lanta District, Ko Lanta Island, 80 m a. s. l. ; Phang Nga Province, Ko Yao District, Ko Yao Noi, 8°9'53˝N, 98°37'20˝E, 150 m a. s. l. ; Thap Put District, Had Lek Beach, 8°37'N, 98°13'E, 10 m a. s. l. ; Khao Lak-Lamru National Park, 8°37'N, 98°14'E, 30–40 m ; Surat Thani Province, Ko Samui District, Samui Island, Khao Phlu, 10–500 m a. s. l. ; Nam Tok Na Muang Forest Park, 30 m a. s. l. ; Ko Pha Ngan District, Phangan Island, Than Sadet-Ko Phangan National Park, 9°44'7˝N, 100°1'10˝E, 320 m a. s. l. (Decker 2010). Malaysia, neighboring the Malay Peninsula (Verhoeff 1906).

New material examined.

Myanmar – Tanintharyi Division • 2 ♂; Myeik, Kala Island; elev. 5 m a. s. l.; 12°29'38″N, 98°30'53″E; 5 Apr. 2016; C. Sutcharit, W. Siriwut, R. Srisonchai leg.; CUMZ -GLO 016-1, 16-2 .

Description.

Body length of unrolled specimens, 17.5–17.9 mm (♂), width 8.9–9.1 (♂).

Color faded after 15 years of preservation in alcohol (Fig. 2 A – C): body blackish, with contrasting light yellow to yellow, broad to narrow bands at posterior edges of each of terga 2–11; axial stripe yellow, short, starting from behind caudal edge, not reaching 1 / 5–1 / 6 length of each tergite (Fig. 2 A); in lateral view, terga 2–11 each with a large, reddish or carmine to red orange band each side, ~ 1 / 4–2 / 3 height of each tergum (Fig. 2 B). Thoracic shield with a very large, lateral, reddish to red orange band each side at lateral edges, ~ 2 / 3–3 / 4 height of tergum in lateral view (Fig. 2 A – C); anal shield (= pygidium) with a reddish to red-orange band at the lateral and posterior edges, ~ 2 / 3–3 / 4 height of tergum (Fig. 2 B). Head, collum and antennae black to dark brown, only labrum and Tömösváry’s organ brownish (Fig. 2 C), venter and legs brownish to pale yellowish (Fig. 2 C).

Labrum sparsely setose (Fig. 2 C). Gnathochilarium with 2 + 2 palps subequal in length. Eyes blackish, with 8–11 + 1 ommatidia, cornea convex and translucent. Antennomere 6 long, ~ 2.3–2.5 × as long as its height, dorsal margin strongly curved (Figs 2 C, 3 A). Disk of antennomere 7 beset with 55–62 small sensory cones apically (♂) (Figs 2 C, 3 A). Organ of Tömösváry typical, horseshoe-shaped, suboval, elongate, ~ 1.5–1.6 × as long as broad.

Collum as usual, with two transverse striae. Thoracic shield with a small hyposchism field not projecting past rear tergal margin (Fig. 2 B); 7–9 mostly superficial striae, only lower two or three lying in front of schism, one or two level to schism, remaining 2–4 behind schism, 6 and 7 complete striae, crossing the dorsum. Terga 3 and 4 relatively broadly rounded laterally (Fig. 2 B). Following terga in front of pygidium faintly concave medially at caudal edge and with three or four striae starting above lateral edge, sometimes first and second stria fading away towards midway. Pygidium slightly concave medially at caudal edge.

♂ legs 17 (Fig. 3 B) simple, rather strongly reduced, with a rather low to medium-sized, often rounded, coxal lobe and a 4 - segmented telopodite. Tarsus with 4–10 strong median and 1–3 strong apical spines (Fig. 3 B).

♂ legs 18 (Fig. 3 C) simple, slightly reduced, without any evident outgrowths; syncoxite membranous, with a small, broad, arch-shaped syncoxite notch and a 4 - segmented telopodite. Tarsus with a small, but strong apical spine.

Telopods (= ♂ legs 19) (Fig. 3 D – F) with a rather large and roundly pentagonal syncoxite lobe, this being flanked by two short, spiniform, acuminate and setose syncoxite horns, the latter being evidently lower than syncoxite lobe (Fig. 3 F). Telopodite 4 - segmented, with a spine apically. Prefemur (Fig. 3 D, E) subtrapeziform, with a conspicuous, elongated, robust, tuberculiform, distomesal prefemoral trichostele with a rounded tip, extending to about half or distal boundary of femur (Fig. 3 D, E). Femur (Fig. 3 D, E) subtrapeziform, with a stout, relatively short femoral trichostele in anterior view, extending apically to ~ 1 / 2–3 / 4 prefemoral trichostele, in posterior view with a rounded, slightly narrowed, subtrapeziform femoral process, this being strongly curved anterolaterally and gently tapering into an acuminate and pointed tip (Fig. 3 D). Tibia stout, gently tapering distad and curved apicobasad towards femoral process, with an evident, distolateral tibial process, this being strongly curved mesad (Fig. 3 E). Tarsus the smallest, subcylindrical, moderately sigmoid, strongly curved, narrowly rounded apically, with a robust and small terminal seta (Fig. 3 D).

Remarks.

The taxonomic status of R. carnifex presents a challenge. Pocock (1889) originally described both Glomeris carnifex and G. carnifex var. pallida in the same paper. However, the original description of G. carnifex lacked details, focusing solely on body coloration and a vague collection locality (south Tenasserim, Myanmar). Pocock (1890) subsequently provided more information regarding the precise sampling locations, viz. south Tenasserim and Malwoon (= Maliwan, Kawthoung, Tanintharyi, Myanmar; Likhitrakarn et al. 2017).

In contrast, the description of G. carnifex var. pallida from Elphinstone Island contained far more detail. Pocock (1889) provided information on the number of specimens (male and female individuals), body characteristics, the 18 th pair of legs and the telopod structure, all accompanied by clear illustrations. Notably, G. carnifex and G. carnifex var. pallida differ only slightly in coloration, showing a central, longitudinal, carmine line and large, lateral, carmine spots on each tergite.

Subsequently, Silvestri (1917) provided a more detailed description, accompanied by comprehensive illustrations, while still treating R. carnifex and R. carnifex var. pallida as two different taxa. He also treated G. bicolor sensu Verhoeff (1906) as a synonym with R. carnifex var. pallida (Pocock, 1889) . In a recent study, Golovatch et al. (2011) formally synonymized R. carnifex var. pallida with R. carnifex .

However, our recently obtained specimens from Kala Island, Myanmar (Fig. 1, green square) closely resemble the original description of G. carnifex var. pallida from Elphinstone Island (Fig. 1, red square) both in color pattern (Fig. 2) and morphological characters, especially the structure of their legs and telopod (Fig. 3) as described by Pocock (1889). These two geographically distant populations (ca 50 km apart) (Fig. 1) share these similarities, indicating that they probably belong to the same taxon. As R. carnifex var. pallida is now synonymized under R. carnifex (Golovatch et al. 2011), we currently identify these specimens from Kala Island, Myanmar as R. carnifex .

Although there were previous reports of R. carnifex from several localities in southern Thailand, preliminary analyses of a number of R. carnifex specimens from this area reveal notable intraspecific variation in coloration, morphology, and molecular genetics, suggesting an occurrence of cryptic species (unpublished data). Therefore, a comprehensive redescription of newly retrieved male specimens from Kala Island, Myanmar in this study, comparing them with the original description of G. carnifex var. pallida from the nearby Elphinstone Island, is essential before any taxonomic revisions of other Thai specimens can be proposed. Furthermore, the morphological redescription of R. carnifex above is thus based only on these Myanmarese specimens.