Sphaerotheca magadha, Prasad & Dinesh & Das & Swamy & Shinde & Vishnu, 2019

Prasad, Vishal Kumar, Dinesh, K. P., Das, Abhijit, Swamy, Priyanka, Shinde, Ajinkya D. & Vishnu, Jadhav Bapurao, 2019, A new species of Sphaerotheca Gunther, 1859 (Amphibia: Anura: Dicroglossidae) from the agro ecosystems of Chota Nagpur Plateau, India, Records of the Zoological Survey of India 119 (3), pp. 197-210 : 198-206

Sphaerotheca magadha sp. nov.

Holotype: ZSI/WRC/A/2178, an adult male (SVL 34.2 mm) collected by Vishal Kumar Prasad and team in July 2015 from semi urbanized agricultural land of Nawadih village (N 24.4179; E 85.4680, 380 meters asl), Koderma , Jharkhand.

Paratypes: ZSI/WRC/A/2179, an adult male (SVL 30.2 mm) and ZSI/WRC/A/2180, an adult female (SVL 41.0 mm) collected by Vishal Kumar Prasad and team July 2015 from semi urbanized agricultural land in Nawadih village (N 24.4179; E 85.4680, 380 meters asl), Koderma , Jharkhand .

Lineage diagnosis: Sphaerotheca magadha sp. nov. can be diagnosed phylogenetically as a member of the Sphaerotheca clade ( Figure 1 ), showing a sister relationship to Sphaerotheca breviceps and exhibiting moderate genetic divergence (16S rRNA - 1.8% to 2.1 %).

Field Diagnosis

Morphology: In the field, Sphaerotheca magadha sp. nov. does not have any morphologically similar congeneric sympatric species, and it can be easily identified on the basis of the combination of morphological characters like medium size, stumpy and squat body, wider head width than head length, rounded snout, angled canthus rostralis, first finger longer than the second (and sub equal to third finger), short hind limbs which do not touch when folded at right angles to the body, tibio-tarsal articulation reaching front of shoulders, moderate webbing, distinct shovel shaped inner metatarsal tubercle and a prominent tarsal tubercle. For comparisons of the new species Sphaerotheca magadha sp. nov. with its phylogenetic sister species Sphaerotheca breviceps and its congeners, see section below.

Geography: This species is known from low to mid elevation (380 m) agricultural lands of semi urbanized Nawadih village, Jharkhand ( Figure 5 ). This species is geographically 1600 km away (aerial distance) from the type locality of the phylogenetic sister species S. breviceps and 1800 km away (aerial distance) from the type locality of the morphologically similar species S. rolandae . Additional sampling and genetic studies are required to establish the range limits of the phylogenetic sister ( S. breviceps ) and the morphologically similar species ( S. rolandae ).

Description of Holotype (ZSI/ WRC/A/2178) ( Figure 2 )

A medium sized burrowing frog (SVL = 34.2 mm) with robust, stumpy and squat body; head width wider than head length (HW = 13.2 mm; HL = 9.6 mm); snout rounded (SL = 5.2 mm) and sub equal to eye diameter (EL = 5.4 mm); canthus rostralis angled, loreal region flat, inter orbital space flat (IUE = 4.0 mm) sub equal to upper lid (UEW = 3.9 mm) and internarial distance (IN = 3.8 mm); distance between back of eyes 1.6 times more than front of eyes (IFE = 6.4 mm; IBE = 10.6 mm); nostrils oval, nearer to tip of snout; symphysial knob moderate; tympanum distinct, minute visible below the supratympanic fold (TYD = 1.2 mm) and close to eye; vomerine ridges present; tongue bifid without a papilla.

Fore arm robust and short (FLL = 6.9 mm) slightly shorter than hand (HAL = 8.8 mm); finger short and thin without any dermal fringes, first finger longer than the second and sub equal to third finger (TFL = mm), tips blunt without any enlarged discs, webbing between fingers absent; subarticular tubercles distinct, rounded and prepollex tubercle distinct, supernumerary tubercles absent.

Hind limbs short, do not touch when folded at right angles to the body and tibio-tarsal articulation reaches front of shoulders; femur length sub equal to tibia length (FL = 15.1 mm; TiL = 13.9 mm); foot length is 2.4 times tarsus length (FOL = 15.9 mm, TAL = 6.4 mm), relative toe length I<II<III<V<IV (FTL = 6.9 mm); inner toe minute (ITL = 0.8 mm), webbing moderate (I 1-2 II 1½- 2½ III 2-2½ IV 2½-1½ V); inner metatarsal tubercle (IMTL = 3.2 mm) distinct and shovel shaped, outer metatarsal tubercle and supernumerary tubercles absent, tarsal tubercle prominent.

In preservative, skin on the dorsum with dotted raised glandular folds; ventrally smooth on throat and belly but granular at the region of back of thighs. Colour on the dorsum washed stone black, surrounding the raised glandular folds blackish giving an overall appearance of blotches on the entire dorsal surface of body, fore arm and hind legs; lateral sides of the body with wider blotches; region of supratympanic fold and canthus rostralis dark; tip of snout with cream white spot; upper lip barred and lower lip and region of rictal gland uniform cream white; fore and hind limbs barred ( Figure 2 ).

Inlife,dorsumlightgreenishbrown,regionsurrounding the raised glandular folds blackish, creamish arch shaped band at the both the sides of the body starting from the region of groin diverging towards the center of dorsum (bands do not meet) at the region of shoulder; at the lateral sides of the body creamish blotches separate the dorsal light greenish brown and the ventral whitish skin; region below the eye, below tympanum creamish and snout tip with a creamish spot; fore arm and hind legs barred; back of thighs and front of groin chocolaty brown without any yellow spots. Eye, diamond shaped pupil black, iris golden brown with fine blackish reticulations ( Figure 3 ).

Secondary Sexual Characters

Adult males have a pair of external vocal sac at the region of throat which is mostly black in colour.

Additional Information from Paratypes, Other Reference Collections and Variations

Morphological data are given in Table 1 . Paratypes range from 30.2 to 41.0 mm in SVL; all the males in the collections were ranging from 28.5 to 34.2 mm in SVL and females were ranging from 32.4 to 41.0 mm in SVL. In all the external morphological characters, holotype and paratypes were similar to the reference collections.

Etymology

The specific epithet is derived from the term ‘Magadha’, an ancient kingdom located on the Indo-Gangetic plains in the eastern Indian state Jharkhand. Suggested common name: ‘Magadha burrowing frog’ species epithet is treated as noun in apposition to generic name.

Distribution and Natural history

Sphaerotheca magadha sp. nov. is known specifically from Joungi and Nawadih village of Koderma district of Jharkhand in Chota Nagpur Plateau. Chota Nagpur Plateau is having geological significance in terms of the continental drift theory ( Mani, 1974; Ghosh et al., 2015). We found this species to be common locally on the road side muddy puddles and it was observed calling and breeding during pre-monsoon showers of June.

Comparisons

Sphaerotheca magadha sp.nov. can be easily distinguished morphologically from its congeners by its combination of characters like medium size, stumpy and squat body, wider head width than head length, rounded snout, angled canthus rostralis, first finger longer than the second (and sub equal to third finger), short hind limbs which do not touch when folded at right angles to the body, tibio-tarsal articulation reaching front of shoulders, moderate webbing, distinct shovel shaped inner metatarsal tubercle and a prominent tarsal tubercle. As of now, none of the species of Sphaerotheca are found to be sympatric in distribution with Sphaerotheca magadha sp. nov. The new species being a member of burrowing frog group showing wide range of distribution, Sphaerotheca magadha sp. nov. is compared with all the known nine species of Sphaerotheca for convenience based on the data from original descriptions.

Multivariate Principal Component Analysis (PCA) was carried out for the six species of Sphaerotheca (male samples only from Padhye et al., (2017)) with the new species. Twenty morphological characters for the male individuals of five species were size corrected by SVL. During the analysis for the male specimens, six different clusters representing Sphaerotheca pluvialis , Sphaerotheca dobsonii , Sphaerotheca breviceps , Sphaerotheca maskeyi and Sphaerotheca pashchima ( Figure 4 ) could be discerned on the PC2 (22.7 % variance) and PC5 (6.4 % variance) axis.

Sphaerotheca magadha sp. nov. can be distinguished from S. breviceps , in having a relatively smaller adult male size of SVL 31.1 mm ±1.9, n=7 (vs relatively larger adult male size SVL 33.4 mm ±7.5, n= 6 in S. breviceps ); lower HL/ SVL ratio of 0.281 to 0.313, n=7 (vs higher HL/SVL ratio of 0.317 to 0.392, n= 6 in S. breviceps ); lower FLL/SVL ratio of 00.182 to 0.213, n=7 (vs higher FLL/SVL ratio of 0.219 to 0.274, n= 6 in S. breviceps ); moderate webbing (I 1-2 II 1½-2½ III 2-2½ IV 2½-1½ V) (vs rudimentary webbing (I 1-2 II 1½-2½ III 2-3½ IV 4-2 V) in S. breviceps ); tarsal tubercle present and distinct (vs tarsal tubercle absent in S. breviceps ); in life dorsum with creamish arch shaped band at the both the sides of the body (vs no band pattern on the dorsum in S. breviceps ); back of thigh and front of groin chocolaty brown (vs back of thigh and front of groin with light yellow blotches in S. breviceps ); type locality and predominant distribution in the Jharkhand landscapes (vs. type locality and predominant distribution in the east coast of India in S. breviceps ) .

Sphaerotheca magadha sp. nov. can be distinguished from S. pluvialis in having a relatively smaller adult male size of SVL 31.1 mm ±1.9, n=7 (vs relatively larger adult male size SVL 43.7, n= 1 in S. pluvialis ); lower HL/SVL ratio of 0.281 to 0.313, n=7 (vs higher HL/SVL ratio of 0.327, n= 1 in S. pluvialis ); lower HW/SVL ratio of 0.319 to 0.388, n=7 (vs higher HW /SVL ratio of 0.403, n= 1 in S. pluvialis ); higher IUE/SVL ratio of 0.072 to 0.117, n=7 (vs lower IUE /SVL ratio of 0.067, n= 1 in S. pluvialis ); lower TYD/SVL ratio of 0.034 to 0.061, n=7 (vs higher TYD/SVL ratio of 0.075, n= 1 in S. pluvialis ); lower FLL/SVL ratio of 0.182 to 0.213, n=7 (vs higher FLL/SVL ratio of 0.247, n= 1 in S. pluvialis ); lower T4L/SVL ratio of 0.185 to 0.223, n=7 (vs higher T4L /SVL ratio of 0.320, n= 1 in S. pluvialis ); moderate webbing (I 1-2 II 1½-2½ III 2-2½ IV 2½-1½ V) (vs rudimentary webbing (I 1-2 II 1-3 III 2-3½ IV 4-2 V) in S. pluvialis ); tarsal tubercle present and distinct (vs tarsal tubercle absent in S. pluvialis ); type locality and predominant distribution in the Jharkhand landscapes (vs. type locality and predominant distribution in the east coast of India in S. pluvialis ).

Sphaerotheca magadha sp. nov. can be distinguished from S. dobsonii in having a relatively smaller adult male size of SVL 31.1 mm ±1.9, n=7 (vs relatively larger adult male size SVL 55.1 mm, n= 1 in S. dobsonii ); lower HL/SVL ratio of 0.281 to 0.313, n=7 (vs higher HL/SVL ratio of 0.336, n= 1 in S. dobsonii ); lower HW/SVL ratio of 0.319 to 0.388, n=7 (vs higher HW /SVL ratio of 0.403, n= 1 in S. dobsonii ); lower TYD/SVL ratio of 0.034 to 0.061, n=7 (vs higher TYD/SVL ratio of 0.064, n= 1 in S. dobsonii ); lower FLL/ SVL ratio of 0.182 to 0.213, n=7 (vs higher FLL/SVL ratio of 0.254, n= 1 in S. dobsonii ); moderate webbing (I 1-2 II 1½-2½ III 2-2½ IV 2½-1½ V) (vs rudimentary webbing (I 1½-2 II 1½-3 III 2½-4 IV 4-2 V) in S. dobsonii ); tarsal tubercle present and distinct (vs tarsal tubercle absent in S. dobsonii ); type locality and predominant distribution in the Jharkhand landscapes (vs. type locality and predominant distribution in the west coast of India in S. dobsonii ).

Sphaerotheca magadha sp. nov. can be distinguished from S. strachani in having wider head than long (vs head longer than wide in S. strachani ); snout rounded (vs snout obtuse in S. strachani ); skin on the back with rounded glandular spots (vs skin on the back with short longitudinal folds in S. strachani ); finger 1 longer than finger 2 (vs finger 1 and 2 are equal in S. strachani ); metatarsal articulation reaches back of eyes (vs metatarsal articulation reaches tip of snout in S. strachani ); outer metatarsal tubercle absent (vs outer metatarsal tubercle present in S. strachani ); toes moderately webbed (vs toes half webbed in S. strachani ); tarsal tubercle present and distinct (vs tarsal tubercle absent in S. strachani ); type locality and predominant distribution in the Jharkhand landscapes (vs. type locality and predominant distribution in the Sindh province of Pakistan in S. strachani ).

Sphaerotheca magadha sp. nov. can be distinguished from S. leucohrynus having a relatively smaller adult male size of SVL 31.1 mm ±1.9, n=7 (vs relatively larger adult male size SVL 35.0 mm in S. leucohrynus ); having wider head than long (vs head longer than wide in S. leucohrynus ); snout rounded (vs snout obtuse in S. leucohrynus ); snout length sub-equal to eye length (vs snout length longer than eye length in S. leucohrynus ); tibio-tarsal articulation reaches front of shoulders (vs tibio-tarsal articulation reaches eye in S. leucohrynus ); toes moderately webbed (vs toes 1/3rd webbed in S. leucohrynus ); outer metatarsal tubercle absent (vs outer metatarsal tubercle present in S. leucohrynus ); tarsal tubercle present and distinct (vs tarsal tubercle absent in S. leucohrynus ); type locality and predominant distribution in the Jharkhand landscapes (vs. known only from the type locality ‘Wattakole, Coorg’ mid elevations of Western Ghats in S. leucohrynus ).

Sphaerotheca magadha sp. nov. can be distinguished from S. swani in having a relatively smaller adult male size of SVL 31.1 mm ±1.9, n=7 (vs relatively larger adult male size SVL 42.3 mm, n= 1 in S. swani ); inter orbital distance equal to upper eyelid width (vs inter orbital distance 3/4 of upper eyelid width in S. swani ); tympanum small about ¼ th of eye length (vs tympanum large about 2/3rd of eye length in S. swani ); tibio-tarsal articulation reaches front of shoulders (vs tibio-tarsal articulation reaches eye in S. swani ); moderate webbing (I 1-2 II 1½-2½ III 2-2½ IV 2½- 1½ V) (vs rudimentary webbing (I 1-2 II 1-3 III 2-3½ IV 3½-2 V) in S. swani ); tarsal tubercle present and distinct (vs tarsal tubercle absent in S. swani ); type locality and predominant distribution in the Jharkhand landscapes (vs. type locality and predominant distribution in the lower elevations of eastern Nepal in S. swani ).

Sphaerotheca magadha sp. nov. can be distinguished from S. rolandae in having nostrils nearer to tip of snout (vs. nostrils equidistant from eye to snout tip in S. rolandae ); inter orbital space equal to upper lid (vs. inter-orbital width broader than that of upper eyelid in S. rolandae ); diameter of the eye nearly four times of the tympanum (vs. tympanum nearly half the diameter of the eye S. rolandae ); first finger longer than the second finger (vs first finger shorter than the second finger in S. rolandae ); tibio-tarsal articulation reaches front of shoulders (vs. tibiotarsal articulation reaches posterior corner of the eye in S. rolandae ); moderate webbing (I 1-2 II 1½-2½ III 2-2½ IV 2½-1½ V) (vs rudimentary webbing (I 1-2 II 1½- 2½ III 2-3½ IV 4½-2 V) in S. rolandae ); in life, dorsum light greenish brown, fore arm and hind legs barred, back of thighs and front of groin chocolaty brown without any yellow spots (vs. in life dorsum uniformly grey limbs with or without darker cross bands; upper surface of thigh black spotted or marbled with white in S. rolandae ); type locality and predominant distribution in the Jharkhand landscapes (vs. type locality and predominant distribution in Sri Lanka for S. rolandae ).

Sphaerotheca magadha sp. nov. can be distinguished from S. maskeyi in having a relatively smaller adult male size of SVL 31.1 mm ±1.9, n=7 (vs relatively larger adult male size SVL 43.7 mm, n= 1 in S. maskeyi ); lower HL/SVL ratio of 0.281 to 0.313, n=7 (vs higher HL/SVL ratio of 0.343, n= 1 in S. maskeyi ); lower HW/SVL ratio of 0.319 to 0.388, n=7 (vs higher HW/SVL ratio of 0.448, n= 1 in S. maskeyi ); lower EL/SVL ratio of 0.135 to 0.160, n=7 (vs higher EL/SVL ratio of 0.162, n= 1 in S. maskeyi ); lower SL/SVL ratio of 0.134 to 0.154, n=7 (vs higher SL/ SVL ratio of 0.161, n= 1 in S. maskeyi ); lower TYD/SVL ratio of 0.034 to 0.061, n=7 (vs higher TYD/SVL ratio of 0.078, n= 1 in S. maskeyi ); lower F2L/SVL ratio of 0.066 to 0.114, n=7 (vs higher F2L/SVL ratio of 0.118, n= 1 in S. maskeyi ); lower FL/SVL ratio of 0.369 to 0.442, n=7 (vs higher FL/SVL ratio of 0.471, n= 1 in S. maskeyi ); lower TL/SVL ratio of 0.361 to 0.408, n=7 (vs higher TL/SVL ratio of 0.412, n= 1 in S. maskeyi ); lower T1L/SVL ratio of 0.020 to 0.031, n=7 (vs higher T1L/SVL ratio of 0.042, n= 1 in S. maskeyi ); T4L/SVL ratio of 0.185 to 0.223, n=7 (vs higher T4L/SVL ratio of 0.328, n= 1 in S. maskeyi ); moderate webbing (I 1-2 II 1½-2½ III 2-2½ IV 2½-1½ V) (vs rudimentary webbing (I 1-2 II 1½-3 III 2-3½ IV 3½-2 V) in S. maskeyi ); tarsal tubercle present and distinct (vs tarsal tubercle absent in S. maskeyi ); type locality and predominant distribution in the Jharkhand landscapes (vs. type locality and predominant distribution in the lower elevations of central Nepal in S. swani ).

Sphaerotheca magadha sp. nov. can be distinguished from S. pashchima , in having a relatively smaller adult male size of SVL 31.1 mm ±1.9, n=7 (vs relatively larger adult male size SVL 44.5 mm ±5.1, n= 7 in S. pashchima ); lower HL/ SVL ratio of 0.281 to 0.313, n=7 (vs higher HL/SVL ratio of 0.317 to 0.353, n= 7 in S. pashchima ); lower TYD/SVL ratio of 0.034 to 0.061, n=7 (vs higher TYD/SVL ratio of 0.061 to 0.068, n= 7 in S. pashchima ); lower FLL/SVL ratio of 0.182 to 0.213, n=7 (vs higher TYD/SVL ratio of 0.223 to 0.289, n= 7 in S. pashchima ); moderate webbing (I 1-2 II 1½-2½ III 2-2½ IV 2½-1½ V) (vs rudimentary webbing (I 1-2 II 1-3 III 2-3½ IV 3½-2 V) in S. pashchima ); tarsal tubercle present and distinct (vs tarsal tubercle absent in S. pashchima ); type locality and predominant distribution in the Jharkhand landscapes (vs type locality from Western Ghats and predominant distribution in the mid elevations of Western Ghats to Uttarakhand in S. pashchima ).

Figures

Figure 1. Maximum Likelihood (ML) tree for the species of Sphaerotheca based on 6518 bp of mitochondrial (16S, 12S, COI and Cytb) and nuclear genes (BDNF, CXCR4, NCX1, RAG1, RAG2, Rhod and Tyro).

Figure 2. Holotype ofSphaerotheca magadha sp. nov. (a) dorsal view; (b) ventral view; (c) ventral view of right hand; (d) ventral view of right foot; (e) arrow showing tarsal tubercle.

Figure 3. Sphaerotheca magadha sp. nov. in life.

Figure 4. Multivariate Principal Component Analysis for six species of Sphaerotheca (data from Padhye et al., (2017) and) with Sphaerotheca magadha sp. nov. (14 morphometric characters marked as * in Table 1 transformed to their ratio to SVL).

Figure 5. Map showing type localities of extant species of Sphaerotheca in South Asia.