Uperodon variegatus ( Stoliczka, 1872 )

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 : 39-41

Uperodon variegatus ( Stoliczka, 1872)

Variegated Globular Frog

( Figs. 1 , 2A , 3K , 5J , 10M–P , 11L–P , 12A , 13 , 14 ; Tables 1–4)

Original name and description. Callula variegata Stoliczka, 1872 . Observations on Indian Batrachia. Proceedings of the Asiatic Society of Bengal, 1872: 101–113. Lectotype. By present designation, ZSI 2761, an adult female, SVL 29.8 mm. Type locality. “Ellore” (=Eluru, Andhra Pradesh) India. Current status of specific name. Valid name, as Uperodon variegatus ( Stoliczka, 1872) . Synonyms. Hylaedactylus carnaticus Jerdon, 1854 “1853” (by Parker 1934), Callula olivacea Günther, 1876 “1875” (by Boulenger 1890), and Ramanella symbioitca Rao and Ramanna, 1925 (by Parker 1934).

Lectotypification of Callula variegata Stoliczka, 1872 . The original description of this species ( Stoliczka 1872) mentions two syntypes from “Ellore”. ZSI 2761 was indicated as one of the syntypes ( Sclater 1892), and for the second specimen NHMW 4019 and BMNH 74.11.12.2 have been suggested as possible candidates ( Tiedemann et al. 1994; Dutta & Manamendra-Arachchi 1996; Dutta 1997; Chanda et al. 2000). In the present study, the available samples at ZSI, Kolkata (ZSI 2761) and Natural History Museum, London (BMNH 74.11.12.2) were examined. Both these specimens were found to be identical in species status and were in agreement with the original description. However, since this species was described based on two specimens, and there have been confusions related to the status of syntypes ( Chanda et al. 2000) as well as species identification (e.g., Rao 1937; Günther 1876 “1875”), apart from the availability of several poorly-defined nominal taxa currently in the synonymy of Uperodon variegatus , in accordance with Article 74 of The Code, designation of a lectotype from syntypes is advisable for it “to become the unique bearer of the name of a nominal species-group taxon and the standard for its application” in order to clarify the taxonomic status of this species. Hence, based on diagnostic characters found useful for differentiating Uperodon variegatus from its congeners (as stated in the ‘comparison’ section below), we herein designate ZSI 2761 (an adult female, SVL 29.8 mm) from “Ellore”, as the lectotype of Callula variegata Stoliczka, 1872 . The lectotype description provided subsequently is consistent with the original description.

Comparison. Uperodon variegatus cannot be confused with any of the known member of this genus, except Uperodon rohani sp. nov., because of its dorsal skin that has prominent spots or blotches, and ventral skin white to off-white without any spots, blotches or mottling. Uperodon variegatus differs from Uperodon rohani sp. nov. by a suite of morphological characters (including osteology) and considerable genetic divergence. For comparison with U. globulosus , U. systoma , U. taprobanicus , U. anamalaiensis , U. montanus , U. mormorata , U. nagaoi , U. obscurus , U. palmatus , U. triangularis and U. rohani sp. nov. see ‘comparison’ sections of those species.

Genetic divergence. For 16S mitochondrial gene sequences, the sampled populations of Uperodon variegatus showed an average intraspecific distance of 0.7% (range 0–1.2%, N = 4). The samples from Karnataka and Kerala (Western Ghats) showed a divergence of up to 1.2% with the populations from Andhra Pradesh and Tamil Nadu (Eastern Ghats). Genetically, U. variegatus is closely related to U. rohani sp. nov., from which it was found to differ by an average uncorrected genetic distance of 2.8% (range 2.4–3.4%, N = 24). For interspecific genetic distances with all other members of the genus, see Table 3.

Description of lectotype (measurements in mm) ( Figs. 3K , 10M ). Small-sized (SVL 29.8), slender adult female; head small (HW 8.7, HL 7.1, IFE 4.3, IBE 8.3), less than one-fourth (23.8%) of body length, wider than long (HW/HL ratio 1.2); snout rounded to nearly truncate in dorsal and ventral view, acute in lateral view, its length (SL 3.2) longer than horizontal diameter of eye (EL 2.7); loreal region obtuse with rounded canthus rostralis; interorbital space more than twice as wide (IUE 3.6) as upper eyelid (UEW 1.4); nostril closer to tip of snout (NS 0.9) than to eye (EN 1.9); supratympanic fold distinct, extending from posterior corner of upper eyelid to insertion of forelimb at axilla; eye diameter (EL 2.7); vomerine odontophores present on the palate, without teeth; presence of two weakly-developed neopalatinal ridges on posterior side of each choana, fused with the vomerine odontophores; tongue emarginate. Forearm (FAL 5.0) shorter than hand length (HAL 7.8); finger length formula I<II<IV<III, tips of all fingers with truncate discs, discs moderately wide compared to finger width; subarticular tubercles prominent, oval, all present; two well-developed palmar tubercles (inner, oval, 1.1 mm long; outer, shallowly lobed, 1.0 mm long). Hind limbs relatively long, thigh length (TL 11.3) longer than shank (SHL 9.9) and shorter than foot (FOL 12.7); tips of all toes with small truncate to rounded discs; webbing absent between toes; dermal fringes absent on all toes; subarticular tubercles prominent, oval; two smooth metatarsal tubercles, oval, outer one longer (1.3 mm long) than the inner (0.7 mm long).

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

Colouration. In preservation: Dorsum uniformly light greyish-brown; flanks greyish-brown; lateral sides of head light brown; ventral surface uniformly light grey ( Figs. 3K ). Colour in life (SDBDU 2007.4994, male). Dorsal surfaces (including limbs) dark brown with scattered olive yellow spots throughout; lateral sides of head dark greyish-brown with scattered olive coloured spots; throat dark grey with calling patch; chest, belly and thigh, fleshwhite without markings; ventral surfaces of forelimb, tibia and foot, light grey ( Fig. 11L–M ).

Variations. Morphometric measurements for 12 males and seven females, including the lectotype, are given in Table 4 . Dorsal colouration and markings were highly variable among the examined specimens. SDBDU 2007.6347: dorsum brown with yellowish-grey blotches in life (that turns light brown with grey blotches in preservation); SDBDU 2005.4726 : light brown with olive grey blotches in life. Albino (or possibly leucistic) forms of this species are known from Mamallapuram in Tamil Nadu ( Fig. 11O ).

Secondary sexual characters. Male: vocal sac externally visible on the lower jaw; females (SDBDU 2005.4726): ova white, pigmented on pole (diameter 0.7–1.0 mm, N = 20).

Geographical distribution and habitat. Uperodon variegatus is a widely distributed species in India. It is known to occur right from Tamil Nadu and Kerala in the south, northwards up to Karnataka , Andhra Pradesh, Telangana , Odisha , Jharkhand and West Bengal ( Fig. 12A ; Tables 1, S1). In the present study, genetically identified individuals of this species were largely collected from urban landscapes and disturbed secondary forests (Tamil Nadu: Chengalpattu and Mamallapuram; Kerala: Karamana, Meladoor and Palakkad; Karnataka: Bangalore; and Andhra Pradesh: Srikakulam ), from sea level up to 900 m elevations. This species is predominantly found in drier regions towards the eastern coast. At Mamallapuram, it was found in brackish waters, just a few metres away from the seacoast.

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 10. Head, hand, foot and foot webbing in Uperodon obscurus, U. palmatus, U. triangularis and U.variegatus. A–D. Holotype ofUperodon obscurus(NHM58.11.28.42 ex.BMNH 1947.2.11.20, female):A. Lateralview of head; B. ventral view of hand; C. ventral view of foot; D. schematic illustration of foot webbing; E–H. Holotype of Uperodon palmatus (NHM 90.11.8.62 ex. BMNH 1947.2.11.21, female): E. Lateral view of head; F. ventral view of hand; G. ventral view of foot; H. schematic illustration of foot webbing; I–L. Lectotype of Uperodon triangularis (NHM 74.4.29.897 ex. BMNH 1947.2.11.15, male): I. Lateral view of head; J. ventral view of hand; K. ventral view of foot; L. schematic illustration of foot webbing; M. Lectotype of Uperodon variegatus (ZSI 2761, female), lateral view of head; N–P. Referred specimen of Uperodon variegatus (ZSI 4726, female): N. ventral view of hand; O. ventral view of foot; P. schematic illustration of foot webbing. (Illustrations: SD Biju).

FIGURE 11. Uperodon palmatus, U. triangularis and U. variegatus in life. A–E. Uperodon palmatus: A. Dorsolateral view (DZ 1372, male); B. dorsolateral view (DZ 1372, male); C. ventral view (DZ 1371, male); D. dorsal view (DZ 1331, male); E. dorsolateral view (DZ 1331, male); F–K. Uperodon triangularis: F. Dorsolateral view (ZSI/WGRC/V/A/959, male); G. dorsal view (SDBDU 2015.2857, male); H. ventral view (SDBDU 2015.2857, male); I. dorsolateral view (SDBDU 2011.502, male); J. dorsolateral view (SDBDU 2012.2200, subadult male); K. dorsofrontal view (SDBDU 2012.2038, male); L–P. Uperodon variegatus: L. Dorsolateral view (not preserved); M. ventral view (SDBDU 2007.4994, male); N. dorsolateral view (not preserved); O. dorsolateral view of an albino (or possibly leucistic) form (not preserved); P. dorsolateral view (not preserved). (Images: SD Biju,Sonali Garg, N & P - Shyamal L, O - Romulus Whitaker).

FIGURE 13. Principal Component Analyses showing morphometric differentiation between Uperodon rohani sp. nov. and U. variegatus based on 17 morphological characters. Left: Plot for the first two factor planes explaining 54.4% of the variations among 28 adult male specimens. Right: Plot for the first two factor planes explaining 73% of the variations among 15 adult female specimens.Factor loadings for each component are provided in Table S2.

FIGURE12. A.Distributionof Uperodon variegatus andUperodon rohani sp. nov. Detailsof localities reported inthe present study are provided in Table 1. Records from literature are listed in supplementary Table S1 and indicated here based on approximatecoordinates; B–E. Head, hand, footand schematic illustration of foot webbing inthe holotype of Uperodonrohani sp. nov. (DZ 1449, male): B. lateral view of head; C. ventral view of hand; D. ventral view of foot; E. foot webbing; F–J. Uperodonrohani sp. nov. (DZ 1449,male) inlife:F. dorsolateral view; G. dorsal view; H.ventral view; I. Uperodon rohanisp. nov. (Paratype,DZ 1485, female),dorsal view; J. Uperodon rohanisp. nov. (DZ 1130, female), dorsolateral view.(Images:SD Biju).

FIGURE14.Cleared and double stainedspecimens of Uperodon rohani sp. nov. (above) and U.variegatus (below).From left to right: Dorsal view of the crania composed of nasals (NS), frontoparietals (FP), prootics (PR), exoccipitals (EX) and squamosals (SQ); anteroventral view of the crania showing components of the upper jaw, premaxillae (PM) and maxillae (MA); ventral view of the lower jaw comprising of dentaries (DN), angulosplenials (AG) and mentomeckelians (MM). Bones are indicated in red, cartilage in blue. (Images: Gayani Senevirathne).