Limnonectes jarujini, Matsui, Masafumi, Panha, Somsak, Khonsue, Wichase & Kuraishi, Norihiro, 2010

Matsui, Masafumi, Panha, Somsak, Khonsue, Wichase & Kuraishi, Norihiro, 2010, Two new species of the “ kuhlii ” complex of the genus Limnonectes from Thailand (Anura: Dicroglossidae), Zootaxa 2615, pp. 1-22 : 15-17

Limnonectes jarujini sp. nov.

Synonymy: Rana kuhlii: Taylor, 1962 , p. 408 (part).

Holotype: CUMZ (A) 7709 (former KUHE 20105), an adult male from near Kaeng Krachan Reservoir, Kaeng Krachan, Phetchaburi Province, Thailand (12o57' N, 99o32' E, 400 m a.s.l.), collected on 11 December 1995 by Masafumi Matsui.

Paratypes: KUHE 20101–02, 20104, 20110–12, 20124–28, 20150–52, 20156, 37137–38, same data as the holotype.

Referred specimens: CUMZ (A) 7711–12 from Khao Wang Kamen, Sai Yok District, Kanchanaburi Province; KUHE 19514, 19529 from Sangkhla Buri, Kanchanaburi Province; KUHE 19940 from near Khao Laem Reservoir, Pilok, Kanchanaburi Province; KUHE 35064–65, 35078–80, 35116, 37135–36 from Pilok, Thong Pha Phum, Kanchanaburi Province; KUHE 23849 from Khao Sok National Park, Surat Thani Province; KUHE 19690 from Khlong Saeng Wildlife Sanctuary, Surat Thani Province; CUMZ (A) 6406–07, 6410 from Yao Yai Island, Phang-Nga Province; USNM 84827–28 from Huey Nang, Khao-Luang, Nakhon Si Thammarat Province.

Etymology: The specific name is dedicated to the late Jarujin Nabhitabhata of National Science Museum of Thailand who actively elucidated faunal diversity in Thailand.

Diagnosis: A medium to large-sized species of the L. kuhlii complex, with adult SVL 59–94 mm in males, 56–69 mm in females. Males have relatively longer head than females. It has usually thin and obscure temporal stripe, and no markings dorsally on body and limbs. Chin marking is also usually not evident. Dorsal warts are indistinct and only partly present. Toe webbing is full and only slightly excised between toes. Second and first fingers are usually subequal in length and nuptial pad is present on the first finger of males.

Description of Holotype (measurements in mm): SVL 93.4; habitus stocky ( Fig. 5 C); head greatly enlarged, slightly longer (46.9) than broad (44.2); snout obtusely pointed, obtuse in profile, projecting beyond lower jaw; eye length (10.4) smaller than snout length (15.6); canthus rounded; lore concave with a weak groove; nostril dorsolateral, on canthus, midway between tip of snout and eye; internarial distance (6.3) slightly wider than interorbital distance (5.9), latter slightly wider than upper eyelid (5.4); pineal spot present on line connecting anterior rims of upper eyelid; tympanic annulus not visible through skin, though present; vomerine teeth in closely set, oblique groups, between choanae separated from one another by one-sixth the length of one group and from choana by a very narrow space, groups beginning on line connecting centers of choanae; lower jaw with a pair of tooth-like projections near symphysis, more than twice depth of mandible at base of projections; tongue oval, deeply notched posteriorly, without papillae; vocal sac and vocal slits absent.

Forelimb heavy, relatively short (46.7); fingers moderately thick, first finger slightly shorter than second, length of first (9.8, measured from distal edge of inner palmar tubercle) slightly smaller than length of eye; fourth finger much longer than second; tips of fingers bluntly rounded, forming pads without circummarginal grooves; no webs between fingers; inner palmar tubercle large (5.5), round, not elevated; middle palmar tubercle round, smaller than inner palmar tubercle, not contacting outer or inner palmar tubercles; outer palmar tubercle subequal to middle tubercle, elongated, slightly elevated; proximal subarticular tubercles prominent, round, elevated; distal subarticular tubercles low, flat and indistinct, nearly bifid on third finger; no supernumerary metacarpal tubercles; distinct flaps of skin along both edges of second and third fingers.

Hindlimb heavy, relatively short (130.2) about three times length of forelimb; tibia short (35.8), heels not overlapping when limbs are held at right angles to body; tibiotarsal articulation of adpressed limb reaching to point far posterior to eye; foot slightly longer (36.7) than tibia; third toe longer than fifth; tips of toes expanded into round, elevated pads lacking grooves (disk diameter of fourth toe 1.9); all toes webbed to middle of disks, webbing forming broad sheet ( Fig. 6 B); webbing formula: I 0 – 0 II 0 – 0 III 0 – 0 IV 0 – 0 V; excision of membrane between two outer toes reaching level middle of middle subarticular tubercle of fourth toe when toes are in contact; a distinct, movable flap of skin on outer edge of fifth toe and on inner edge of first toe; subarticular tubercles oval and distinctly raised; an oval inner metatarsal tubercle, length (6.3), more than half length of first toe (10.9); no outer metatarsal tubercle.

Dorsum weakly rugose, with low ridges radiating from low, rounded small warts; top of snout without tubercles; eyelid with low tubercles posteriorly; weak, transverse fold between posterior margins of eyes; no dorsolateral row of tubercles; a strong, supratympanic fold from eye to above axilla; side of trunk scattered with large, flat tubercles; dorsal surface of hindlimb laterally and posteriorly with weak warts of various sizes tipped with translucent spinules ( Fig. 6 E); tarsus with a thick dermal ridge extending proximally from metatarsal tubercle; throat rugose, chest and abdomen smooth; skin of gular region not modified. A distinct brownish tinge, with minute asperities, forming a nuptial pad covering medial and dorsal surfaces of first finger from its base to level of base of disc.

Color: In preservative, dorsum grayish brown without marking ( Fig. 5 C); head with a narrow light band posterior to dark interorbital bar; a narrow oblique blackish brown temporal stripe beginning behind eye reaching inguinal area; side of head from posterior half of lore to inguinal area lighter; upper lip irregularly scattered with dark grayish brown; lower lip indistinctly barred with light brown; no dark brown stripe on anterior side of upper arm; limbs without distinct marking; rear of thigh without light spots; anterior half of throat weakly mottled with gray; chest and abdomen immaculate cream ( Fig. 5 D); ventral surfaces of hand and foot dark brown.

Variation: Individual variation in size and body proportions is given in Table 2. In adults, males are significantly larger than females in SVL (mean = 72.9 mm vs. 62.0 mm; Tukey-Kramer test, P <0.05) and RHL (see above). More than half (63% of 16 adults examined) had a thin light-colored postorbital bar, while some (13%) had a wide and very distinct bar. It was found only as a trace (19%) or lacking (6%). Temporal stripe was normally narrow (56%), and wide stripe was much less in frequency (25%). The remaining 19% had a wide and very distinct stripe. Dorsal spots were usually absent (81%) or few and weak (13%), and was rarely strong and present all over dorsum (6%). Chin was dusty (44%) or with weak spots or dots (38%), and sometimes without marking (19%). Dark stripe on upper arm was normally absent (81%) or weak and interrupted (6%), and clear and continuous stripe was seen in a few (13%). Dorsal warts were usually very few and partly distributed (88%), and a few completely lacked warts (6%). Denser warts were seen only on part of dorsum in the remaining 6%. Warts were present less than half or absent on the tibia (31%), and at most weak, though present allover the tibia (25%). In the remaining specimens, warts occupied about half (25%) or two-thirds of the tibia (19%). The second and first fingers were normally subequal (75%), but some had second longer than first (19%), and a few had first longer than second (6%).

Eggs: The diameter of eight ovarian eggs from one female ranged from 1.85–2.23 (mean±1SD = 1.99±0.14) mm. The animal hemisphere of egg is dark brown and the vegetal hemisphere is pale yellow in color.

Comparisons: Limnonectes jarujini differs from L. namiyei , L. fragilis , and L. kuhlii in the same way as in L. taylori . It differs from L. taylori as noted above. In males, the new species has larger SVL, relatively narrower internarial and upper eyelid, and shorter hindlimb and inner metatarsal tubercle than L. fujianensis . Moreover, it lacks many ridges on back and nuptial pad on second finger unlike L. fujianensis . From L. bannaensis , it differs in the absence of nuptial pad on second finger. Limnonectes jarujini differs from L. megastomias in relatively narrower interorbital, lack of nuptial pad on the second finger, which is not constantly longer than first, and not heavily pigmented venter.

Range: Southwestern to southern regions of Thailand. Besides the type locality, Kaeng Krachan, Phetchaburi Province, the species was recorded from the following localities. Kanchanaburi Province: Sangkhla Buri, Khao Laem, Pilok, Sai Yok; Surat Thani Province: Khlong Saeng, Khao Sok; Nakhon Si Thammarat Province: Khao-Luang; Phang-Nga Province: Yao Yai Island.

Natural history: Type series were obtained from a montane stream near a large reservoir. In mid- December, males were calling at dusk in a large pool of a stream (width> 5 m). They were, however, very nervous and their calls could not be recorded. Calls were quite different from those of presumed L. taylori to the human ear. Associated species observed at the type locality were Leptolalax melanoleucus , Rana nigrovittata , and Micryletta inornata .

Karyotype: Diploid chromosome number is 22, with six large and five small pairs. Chromosomes forming pairs 2 and 7 are submetacentric and the remaining nine pairs are metacentric. Secondary constrictions are not recognized (Matsui, unpublished data).

Figures

FIGURE 5. Male holotypes of (A, B) Limnonectes taylori (CUMZ (A) 7708 [former KUHE 19040]), and (C, D) L. jarujini (CUMZ (A) 7709 [= KUHE 20105]); dorsal (A, C) and ventral views (B, D). Scale bar = 10 mm.

FIGURE 6. Toe web (A – C, ventral views) and tibia (D – F, dorsal views) of holotypes of (A, D) Limnonectes taylori and (B, E) L. jarujini, and (C, F) L. megastomias (THNHM 0 0 644 from Pang Sida National Park, Sa Kaeo Province). Not to scale.