Uperodon montanus

Garg, Sonali, Senevirathne, Gayani, Wijayathilaka, Nayana, Phuge, Samadhan, Deuti, Kaushik, Manamendra-Arachchi, Kelum, Meegaskumbura, Madhava & Biju, Sd, 2018, An integrative taxonomic review of the South Asian microhylid genus Uperodon, Zootaxa 4384 (1), pp. 1-88 : 28-29

Uperodon montanus ( Jerdon, 1854 “1853”)

Mountain Globular Frog

( Figs. 1 , 2A, 2C , 3E , 5E , 6G–L , 7F–L ; Tables 1–4)

Original name and description. Hylaedactylus montanus Jerdon, 1854 “1853”. Catalogue of reptiles inhabiting the Peninsula of India. Journal of the Asiatic Society of Bengal, 22:522–534. Holotype. By monotypy, NHM 72.4.17.212 (ex. BMNH 1947.2.11.19), an adult female, SVL 28.3 mm. Type locality. “Mountain streams in Wynaad”, Kerala, India. Current status of specific name. Valid name, as Uperodon montanus ( Jerdon, 1854 “1853”).

Comments. The original description by Jerdon (1854 “1853”) was brief and subsequently elaborated by Parker (1934). This species is largely known only from its original collection and some scanty reports or checklists (e.g., Dutta 1997; Subramanian et al. 2013). Further, considering the recent taxonomic placement of this taxon in genus Uperodon and morphological variations observed among populations (particularly in foot webbing), here we provide a detailed redescription of the holotype and comparison of this species with all its presently recognized congeners, to facilitate proper identification.

Comparison. For comparison of Uperodon montanus with U. globulosus , U. systoma , U. taprobanicus and U. anamalaiensis see ‘comparison’ section of those species. Uperodon montanus differs from U. nagaoi , U. rohani sp. nov. and U. variegatus by presence of prominent spots and blotches on its ventral surface (vs. inconspicuous spots and speckles present or absent in U. nagaoi , and completely absent in U. rohani sp. nov. and U. variegatus ) and relatively smaller snout-vent size, male SVL 21–28 mm, N = 12; female SVL 28–34 mm, N = 8 (vs. relatively larger, U. nagaoi : male SVL 25–32 mm, N = 8; U. rohani sp. nov.: male SVL 26–34 mm, N = 16, female SVL 28– 35 mm, N = 8; U. variegatus : male SVL 25–33 mm, N = 12, female SVL 29–36 mm, N = 7). Uperodon montanus could be confused with U. anamalaiensis , U. mormorata , U. obscurus , U. palmatus and U. triangularis due to presence of prominent spots and blotches on its ventral skin surface. However, U. montanus differs from all these species by its relatively smaller snout-vent size, male SVL 21–28 mm, N = 12; female SVL 28–34 mm, N = 8 (vs. relatively larger, U. anamalaiensis : male SVL 25–37 mm, N = 14, female SVL 35–39 mm, N = 4; U. mormorata : male SVL 31–40 mm, N = 9, female SVL 32–43 mm, N = 3; U. obscurus : male SVL 22–31 mm, N = 17, female SVL 30–38 mm, N = 5; U. palmatus : male SVL 27–31 mm, N = 4, female SVL 34–36 mm, N = 2; U. triangularis : male SVL 25–37 mm, N = 20, female SVL 33–42 mm, N = 4). Specifically, U. montanus also differs from U. mormorata by its ventral skin being light to dark brown with scattered grey spots or blotches (vs. dark brown with dense marbling); from U. palmatus by its snout longer than eye diameter, male: EL/SL ratio 0.6–0.8, N = 12, female: EL/SL ratio 0.6–0.8, N = 8 (vs. equal, male: EL/SL ratio 1.0, N = 4, female: EL/SL ratio 1.0, N =2); and from U. triangularis by presence of webbing between toes (vs. absent).

Genetic divergence. For 16S mitochondrial gene sequences, the sampled populations of Uperodon montanus showed an average intraspecific distance of 0.7% (range 0–1.2%, N = 10). Genetically, U. montanus is closely related to U. anamalaiensis , from which it was found to differ by an average uncorrected genetic distance of 3.2% (range 2.6–4.0%, N = 60). For interspecific genetic distances with all other members of the genus, see Table 3.

Redescription of holotype (measurements in mm) ( Fig. 3E ). Small-sized (SVL 28.3), slender adult female; head small (HW 10.1, HL 7.0, IFE 3.9, IBE 7.5), one-fourth (24.7%) of body length, wider than long (HW/HL ratio 1.4); snout nearly rounded in dorsal and ventral view, nearly acute in lateral view, its length (SL 3.3) longer than horizontal diameter of eye (EL 2.1); loreal region obtuse with rounded canthus rostralis; interorbital space nearly twice as wide (IUE 3.1) as upper eyelid width (UEW 1.6); nostril closer to tip of snout (NS 0.8) than to eye (EN 2.1); supratympanic fold distinct, extending from posterior corner of upper eyelid to insertion of forelimb at axilla; eye diameter (EL 2.1); vomerine odontophores present on the palate; indistinct neopalatinal ridges on posterior side of each choana, appear fused with the vomerine odontophores; tongue moderately large, circular, shallowly emarginated. Forelimbs moderately long and thin; forearm (FAL 6.8) shorter than hand length (HAL 8.7); finger length formula I<II<IV<III. Hind limbs relatively long and thin, thigh length (TL 12.3) shorter than shank (SHL 12.4) and foot (FOL 13.9).

Skin of snout, between eyes, sides of head, and anterior part of dorsum, shagreened to granular; posterior part of back, and upper and lower parts of flank, granular ( Figs. 3E ); dorsal surfaces of forelimb, thigh, tibia and tarsus, shagreened to sparsely granular; ventral surface uniformly shagreened ( Fig. 3E ).

Since the hand and foot morphology could not be reliably determined due to poor preservation of the holotype specimen, we are describing these characters based on a topotype specimen (SDBDU 2011.849).

Topotype specimen (SDBDU 2011.849). Hand ( Fig. 7G ): tips of all fingers with truncate discs, moderately wide compared to finger width (FD I 0.6, FW I 0.3; FD II 1.0, FW II 0.7; FD III 1.0, FW III 0.7; FD IV 0.9, FW IV 0.4); welldeveloped dermal fringes present on all fingers; subarticular tubercles rather prominent, oval, all present; two welldeveloped palmar tubercles (inner, oval, 0.8 mm; outer, bilobed, 1.1 mm). Foot ( Figs. 7H–I ): tips of all toes with small rounded discs, rather wide compared to toe width (TD I 0.5, TW I 0.4; TD II 0.6, TW II 0.4; TD III 0.6, TW III 0.5; TD IV 0.6, TW IV 0.4; TD V 0.5, TW V 0.4); well-developed dermal fringes present on all toes; subarticular tubercles rather prominent, oval; two metatarsal tubercles, oval, outer (0.5 mm long) slightly larger than the inner (0.9 mm long); webbing present, basal: I2 – 2II 2 – 3III 3 – 4IV 4 – 3V.

Colouration. In preservation (SDBDU 2011.849): Dorsum greyish-brown; flanks, forelimbs, dorsal surfaces of thigh, shank and foot, light greyish-brown; chest and belly dark grey with light grey spots and patches, ventral surfaces of thigh, tibia and foot, light grey with lighter grey spots. Colour in life (SDBDU 2011.849): Dorsum and lateral sides of head uniformly dark brown with pale brown median patch on the back and few irregular patches near groin and thigh; dorsal surface of limbs dark brown; ventral surface dark brown with irregular white spots and blotches ( Fig. 6G ).

Variations. Morphometric measurements of 20 specimens, including the holotype, are given in Table 4 . Dorsal colouration and webbing is highly variable in this species. Foot webbing: basal in SDBDU 2011.849 (male), I2 – 2II 2 – 3III 3 – 4IV 4 – 3V; medium in SDBDU 2015.3001 (male), I2 – – 2II 2– – 3III 2 – 3IV 3 – 2 1/ 2V; medium in SDBDU 2003.40115 (female), I2 – 2II 2– – 3– III2 – 3 + IV3 – – 2V; and medium in SDBDU 2005.30 (female), I2 – 2II 2– – 3III 2 – 3IV 3 – 2V ( Figs. 7I –L ). SDBDU 2011.849 (male): Dorsum uniformly brown with faint grey markings; SDBDU 2015.3001 (male): colour in life: dorsum orangish-brown with dark brown median patch on the back and few irregular patches near groin and thigh, forelimbs orangish-brown, and hind limbs orangish-yellow with dark brown cross bands ( Fig. 6K ); colour in preservation: dorsum grey with brown median patch and irregular brown spots, brown stripe between eyes, posterior part of dorsum (near groin) with two brown blotches on either side, dorsal surface of hand and foot grey with dark brown cross bands; SDBDU 2015.3002 (female): dorsum prominently granular, dorsal markings almost similar to SDBDU 2015.3001.

Note. Parker (1934) illustrated the foot webbing for this species (figure 38, p. 91) and showed relatively more webbing in the male compared to the female. He also stated toes to be “half webbed in males” and “1/3 webbed in females”. In our study (N = 20), we found webbing to be highly variable, and since females were also often found to have more extensive webbing than males, this character should not be considered reliable for diagnosing this species.

Secondary sexual characters. Male: Vocal sac externally visible on the lower jaw; female (SDBDU 2002.24B): ova white, pigmented on pole (diameter 0.9–1.5mm, N = 20).

Geographical distribution and habitat. Uperodon montanus was originally described from the Wayanad region. In the present study, it is confirmed to occur in the Western Ghats states of Kerala (Devikulam, Munnar, Upper Manalar, Pandimotta, Nelliyampathy, Siruvani, Kurichiyarmala, Settukunnu and Thirunelli) and Tamil Nadu (Kakkachi and Sengaltheri), predominantly from mid to high elevations ranging from 800–1700 m asl ( Fig. 2C ; Table 1). Individuals were collected either from water-filled tree holes, damp leaf litter on forest floor or ground puddles. This species is likely to be distributed in southern parts of Karnataka. However, reports of U. montanus from Gujarat, Maharashtra and northern Karnataka require confirmation and may refer to U. mormorata (see Supplementary Table S1 and references thereto).

Figures

FIGURE 1. Maximum Likelihood phylogram based on 511 bp of mitochondrial 16S rRNA gene sequences from 73 individuals representing all known members of the genus Uperodon. Three samples representing taxon under synonymy are shown inquotationmarks.Outgroup not shown for graphical purposes.BayesianPosterior Probabilities and bootstrap values of>50 are shown above and below the branches, respectively. Values towards the species labels represent mean uncorrected genetic distances between the species with range values in parentheses.

FIGURE 2. A. Geographic distribution of the genus Uperodon in Bangladesh, Bhutan, India, Nepal, Pakistan and Sri Lanka; B. Distributionof Uperodon globulosus, U. systomaand U.taprobanicus; C. Distribution of four endemic Uperodon species of the Western Ghats (excluding the widely distributed Indian member U. variegatus, shown in Fig.12A); D. Distribution of four endemic Uperdodon species of Sri Lanka. Details of localities reported in the present study are provided in Table 1. Records from literature are listed in supplementary Table S1 and indicated here based onapproximate coordinates.

FIGURE 3. Preserved type specimens of Uperodon species in dorsal and ventral view. A. Uperodon systoma, Syntype, ZMB 3551 (female); B. Uperodon globulosus, Syntype, NHM 62.12.29.4 (ex. BMNH 1947.2.10.97) (female); C. Kaloula pulchra taprobanica, Holotype, NHM 1905.3.25.138 (ex. BMNH 1947.2.10.62) (female); D. Ramanella anamalaiensis, Neotype, ZSI/ WGRC/V/A/956 (male); E. Hylaedactylus montanus, Holotype, NHM 72.4.17.212 (ex. BMNH 1947.2.11.19) (female); F. Ramanella mormorata, Neotype, ZSI/WGRC/V/A/958, (female); G. Ramanella nagaoi, Holotype, WHT 2826 (male); H. Callula obscura, Holotype, NHM 58.11.28.42 (ex. BMNH 1947.2.11.20) (female); I. Ramanella palmata, Holotype, NHM 90.11.8.62 (ex.BMNH 1947.2.11.21); J. Callula triangularis, Lectotype, NHM 74.4.29.897 (ex.BMNH 1947.2.11.15) (male); K.Hylaedactylus carnaticus, Lectotype, ZSI 2761(female); L. Uperodonrohani sp. nov., Holotype, DZ1449 (male).(Images: SD Biju and Sonali Garg).

FIGURE 5. Ventral surface of the palate in Uperodon species showing vomerine odontophores separated or fused with dermal projectionsand/or neopalatinalridgeson posterior sides ofthe choanae (indicated witharrows).A. Uperodon systoma, SDBDU 2005.2787 (female) and SDBDU 2005.2806 (male); B. Uperodon globulosus, SDBDU 2014.2673 (female) and SDBDU 2005.4762 (female); C. Uperodon taprobanicus, SDBDU 2007.6364 (female) and SDBDU 2005.4732A (male); D. Uperodon anamalaiensis, SDBDU 2013.2302 (female) and SDBDU 2002.3050 (male); E. Uperodon montanus, SDBDU 2002.24B (female) and SDBDU 2003.40115 (male); F. Uperodon mormorata, SDBDU 2011.507 (male) and SDBDU 2012.43 (male); G. Uperodon obscurus, DZ 1366 (male); H. Uperodon palmatus, DZ 1331 (male); I. Uperodon triangularis, SDBDU 2007.6400 (female) and ZSI/WGRC/V/A/959 (male); J. Uperodon variegatus, SDBDU 2005.4726 (female) and SDBDU 2005.4727 (male); K.Uperodon rohani sp. nov., DZ 1521 (male).(Images:SD Biju).

FIGURE 6. Uperodon taprobanicus, U. anamalaiensis and U. montanus in life. A–C. Uperodon taprobanicus (SDBDU 2014.2567, male): A. dorsolateral view; B. dorsal view; C. ventral view; D–F. Uperodon anamalaiensis: D. dorsolateral view (SDBDU 2013.2302, female); E. dorsal view (SDBDU 2017.3507, female); F. ventral view (SDBDU 2017.3507, female); G– L. Uperodon montanus: G. dorsolateral view (SDBDU 2011.849, male); H. dorsolateral view (SDBDU 2011.1197, male); I. ventral view (SDBDU 2002.1925, male); J. dorsolateralview (SDBDU 2002.1925, male); K.dorsal view (SDBDU 2015.3001, male); L. dorsal view (SDBDU 2011.905, male). (Images: SD Biju and Sonali Garg).

FIGURE7. Head, hand, foot and foot webbing in Uperodon anamalaiensis, U. montanus, U. mormorata and U. nagaoi. A–E. Uperodon anamalaiensis: A–D. Neotype of Uperodon anamalaiensis (ZSI/WGRC/V/A/956, male):A. lateral view of head; B. ventral view of hand; C. ventral view of foot; D. schematic illustration of foot webbing; E. schematic illustration of foot webbing in referred specimen of U. anamalaiensis (SDBDU 2013.928, female); F–L. Uperodon montanus: F–H. Topotype of Uperodon montanus (SDBDU 2011.849, male): F. lateral view of head; G. ventral view of hand; H. ventral view of foot; I. schematic illustration of foot webbing; J–L. schematic illustration of foot webbing in referred specimens of Uperodon montanus: J. SDBDU 2015.3001, male; K. SDBDU 2003.40115, female; L. SDBDU 2005.30, female; M–S. Uperodon mormorata: M–P. Neotype of Uperodon mormorata (ZSI/WGRC/V/A/958, female): M. lateral view of head; N. ventral view of hand; O. ventral view of foot; P. schematic illustration of foot webbing; Q–S. schematic illustration of foot webbing in referred specimens of Uperodon mormorata: Q. SDBDU 2002.567, female; R. SDBDU2012.43, male; S. SDBDU 2015.3082, male.T–W. Holotype of Uperodon nagaoi (WHT 2826, male):T. lateral view ofhead;U. ventral view of hand;V. ventral view of foot; W. schematic illustration of foot webbing. (Illustrations:SD Biju).