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Measurements and terminology follow Bossuyt and Dubois (2001) as listed below, except for a few new characters (1-6, 10, 16, 19, 27, 34, 36 and 49). Morphological measurements were made using Mitutoyo Digimatic Caliper, taken to the nearest 0.1 mm and abbreviated as follows: 1. AG–axilla to groin distance; 2. BWBS– body width behind shoulders (region of axilla); 3. BWFL–body width in front of legs (region of groin); 4. DBDB–distance between dorsolateral bands; 5. DBL–dorsolateral band length; 6. DBW–dorsolateral band width at mid–dorsum; 7. EL–eye length (eye horizontal diameter); 8. EN–distance from front of eye to nostril; 9. fd1,2,3,4–disk width of finger 1,2,3 and 4 respectively; 10. FFL–first finger length; 11. FFTF–distance from maximum incurvature of web between fourth and fifth toe to tip of fourth toe; 12. FL–femur length (from vent to knee); 13. FLL–forelimb length (from elbow to base of outer palmar tubercle); 14. FOL–foot length (from base of inner metatarsal tubercle to tip of fourth toe); 15. FrFL–length of fourth toe (from basal border of proximal subarticular tubercle to tip of fourth toe); 16. FW–femur width; 17. fw1,2,3,4–width of finger 1,2,3 and 4; 18. HAL–hand length (from base of outer palmar tubercle to tip of third finger); 19. HD–head depth; 20. HL–head length (from back of mandible to tip of snout); 21. HW–head width; 22. IBE–distance between posterior corner of eyes; 23. IFE–distance between anterior corner of eyes; 24. IMT–length of inner metatarsal tubercle; 25. IN–internarial space; 26. IUE–minimum distance between upper eyelids; 27. LP–lingual papilla; 28. MBE–distance from back of mandible to back of eye; 29. MFE–distance from back of mandible to front of eye; 30. MN–distance from back of mandible to nostril; 31. MTFF–distance from distal edge of metatarsal tubercle to maximum incurvature of web between fourth and fifth toe; 32. MTTF–distance from distal edge of metatarsal tubercle to maximum incurvature of web between third and fourth toe; 33. NS–distance from nostril to tip of snout; 34. SFL–second finger length; 35. SL–distance from front of eye to tip of snout; 36. STF– supratympanic fold; 37. SVL–snout vent length; 38. td1,2,3,4,5–disk width of toe 1,2,3,4 and 5; 39. TFL–length of third finger (from basal border of proximal subarticular tubercle); 40. TFOL–length of tarsus and foot (from base of tarsus to tip of fourth toe); 41. TFTF–distance from maximum incurvation of web between third and fourth toe to tip of fourth toe; 42. T1L,T2L,T3L,T4L,T5L–length of toe 1,2,3,4 and 5; 43. TL–tibia length; 44. TW–tibia width; 45. tw1,2,3,4,5–width of toe 1,2,3,4 and 5; 46. TYD–tympanum horizontal diameter; 47. TYE–tympanum to eye; 48. UEW–maximum width of upper eyelid; 49. WF–webbing in foot.
Philautus ochlandrae sp. nov. (Figure 1a–h; Table 1)
Holotype : Zoological Survey of India, WGFRS, Calicut (ZSI/WGFRS/V/A/632), an adult male from Ochlandra setigera reed was collected at Kakkayam Reserve Forest, Calicut District, Kerala State, by DKP, MdJP and KVG on 23rd April 2007 (11°33’16” N, 75°55’12” E, altitude ~745 m above mean sea level) between 17:30–22:00 h.
Paratypes : ZSI/WGFRS/V/A/633, 634, two males and ZSI/WGFRS/V/A/635, 636, a male and a female collected from the same locality on 24th April 2007 at 08:00 h by DKP, MdJP and KVG, collection data same as holotype. ZSI/WGFRS/V/A/637, a male collected by DKP and KVG on 27th April 2007 at 21:00 h from the same locality.
Diagnosis : A small-sized frog diagnosed as Philautus (Male: 22.1–25.6 mm; Female: 23.3 mm), having granular belly, all digits with well differentiated disks bearing circummarginal grooves, predominantly inhabiting shrubs (this species exclusively inhabits hollow tubular internodes of O. setigera reed brake) and having direct development as in Philautus cf. leucorhinus (Gururaja & Ramachandra, 2006). It is distinguished from all other congeners of Western Ghats by the following combination of characters: (i) body small, elongate (ii) habitus squat and flat; (iii) head arched, wider than long; (iv) snout short rounded, equal or sub equal to diameter of eye; (v) tympanum indistinct but visible; (vi) canthus rostralis rounded; (vii) eyes protruding, pupil with striking golden yellow dentition like marks; (viii) belly granular, under parts of forearm and thigh granular; (ix) vocal sac unpigmented and (x) fleshy brown to cream yellow dorsum with two distinct golden yellow lateral bands bordered by dark brown from upper eyelid to the posterior part of flanks.
Description of the holotype : A small sized shrub frog (SVL = 25.6 mm), width of head broader than head length (HW = 8.6 mm; HL = 6.4 mm), arched, flat dorsally; snout rounded in total profile, slightly protruding beyond mouth. Snout length is equal to diameter of eye (SL = 2.9 mm, EL = 2.9 mm). Canthus rostralis rounded, loreal region slightly concave. Interorbital space (IUE = 2.8 mm) flat and broader than upper eyelid (UEW = 1.9 mm), wider than internarial distance (IN = 1.7 mm). Internarial distance between posterior margins of the eyes 1.93 times that of anterior margins (IFE = 4.0, IBE = 7.7 mm). Nostrils oval, nearer to tip of snout (NS = 0.8 mm) and away from eye (EN = 1.9 mm). Pineal ocellus absent. Weak symphysial knob. Vomerine ridges absent. Eyes large, protruding, pupil horizontal, with golden yellow dentition like marks interspersed with black. Tympanum rather indistinct, rounded, barely visible behind the eye, 2.15 times in eye diameter (TYD = 1.4 mm). Tongue bifid, granular with a distinct retractile papilla. Supratympanic fold from behind eye to shoulder. Median subgular vocal sac with a pair of opening at the base of the lower jaw.
Fore arm (FLL = 4.4 mm) less than hand (HAL = 7.0 mm). Relative length of fingers I less than II less than IV less than III. Finger tips with well developed disks (fd1 = 0.8 mm, fd2 = 1.1 mm, fd3 = 1.4 mm, fd4 = 1.4 mm; fw1 = 0.5 mm, fw2 = 0.6 mm, fw3 = 0.9 mm, fw4 = 0.8 mm) with distinct circum–marginal grooves, fingers with dermal fringes on both sides. Webbing on palm absent, subarticular tubercles indistinct, rounded and pre–pollex tubercle oval, distinct. Supernumerary tubercles absent.
Hind limb long, heels barely touch when folded at right angles to the body. Tibia 2.9 times longer than wide (TL = 10.1 mm, TW = 3.4 mm), subequal to femur (FL = 10.4 mm) and longer than foot (FOL = 9.5 mm). Heel to tip of fourth toe (TFOL = 14.9 mm) 2.76 times length of fourth toe (T4L = 5.4 mm). Relative toe length I less than II less than III less than V less than IV. Toe disk width and toe width are td1 = 0.8 mm, td2 = 1.0 mm, td3 = 1.3 mm, td4 = 1.5mm, td5 = 1.5 mm; tw1 = 0.7 mm, tw2 = 0.7 mm, tw3 = 0.8 mm, tw4 = 0.9 mm, tw5 = 0.9 mm. Webbing moderate and distinct (MTTF = 5.5 mm, MTFF = 5.5 mm, TFTF = 4.4 mm, FFTF = 3.9 mm); web formula, I 2–2 II 1– 2 III 1–2 IV 2–1 V. Tibiotarsal articulation reaches tympanic region. First toe (T1L = 1.5 mm) nearly 1.9 times the length of inner metatarsal tubercle (IMT = 0.8 mm). Outer metatarsal tubercle, supernumerary tubercles and tarsal tubercle absent.
Skin : Snout, between eyes, sides of head, dorsum smooth. Dorsal part of forelimb, femur, tibia and tarsus smooth to very finely granular. Venter granular, larger granulation on belly extending up to throat, flanks (mid part of dorsolateral band) and thigh. Dorso–lateral folds and macroglands absent.
Color in life : Dorsum fleshy brown with two lateral golden yellow bands bordered by dark brown from upper eyelid to the posterior part of the flanks (¾ of flank). Head, forelimbs and hind limbs brown dorsally. Hand ventrally cream, a few brown granulation along the dermal fringes of third and fourth finger. Upper lip and lower lip cream colored. Venter granular and uniform cream. Granulation on femur, tibia, tarsus and entire foot, brown ventrally. Webbing brown. Eyes with horizontal black pupil surrounded by golden yellow dentition like marks interspersed with black.
Color in preservative : Dorsum and lateral parts of body light sandy brown with two lateral golden yellow bands, bordered by dark brown color from upper eyelid to the region of groin. Dorsal and lateral parts of limbs uniform without any cross bars. Ventral parts of head, body and hand cream white, belly translucent, granular. Granulation on foot, toes, disks and webbing, brown dorso–ventrally.
Etymology : The species epithet refers to the generic name of Ochlandra setigera, the plant in which we observed this species (both male and female) as well as its eggs and advertisement calls.
Sexual dimorphism : Nuptial spines absent in male, possess a median subgular vocal sac with a pair of openings at the base of the lower jaw. Female larger than the paired male (SVL: 23.3 mm and 22.1 mm respectively). Ovary large, with creamy white eggs. Female paler than males, dorsum golden yellow and two lateral stripes slightly thinner than males.
Variation : Table 1 details the morphometric and meristic variations observed in six individuals. Color on the dorsum varied from dark brown to brown interspersed with yellow blotches to broad yellow bands (this is apart from two lateral distinct golden yellow bands from upper eyelid to the posterior part of the flanks). In individuals with brown dorsum and yellow spots, the yellow spots were in four–six stripes, two stripes commencing at snout dividing in to four at interorbital space, and widening at mid dorsum to which two more stripes are added that coalesce near vent. In individuals with brown dorsum and yellow stripes, the yellow stripe starts singly at snout, bifurcating at dorsum and ending near vent. Dorsum of forelimb and hind limb brown with yellow blotches. A yellow stripe along the canthus rostralis was also noticed in an individual.
Additional information from paratypes : Morphometric data are given in Table 1. All the paratypes are in good condition, except for ZSI/WGFRS/V/A/636, which was incised ventrally to determine sex.
Ecology and natural history notes : This species was first noticed on a reed brake on 23rd April 2007 calling at 19:30 h while it was drizzling. Other species calling at that time were Nyctibatrachus cf. aliciae Inger, Shaffer, Koshy and Bakde, Sylvirana aurantiaca (Boulenger), Philautus cf. wynaadensis, and P. ponmudi. Two more individuals were collected during the same night from reed brakes. On 24th April 2007 at 8:00 h, two individuals were collected, of which one was female.
These frogs reside in the hollow tube of internodal region of O. setigera reed brake. On four occasions, calling males were noticed inside culms of O. setigera. Generally, this species remain within these culms throughout the day at a height of 2.42 ± 0.25 m (range: 2.25–2.7 m) above ground. These culms (girth: 81.5 ± 9.4 cm, range: 70–93 cm) had slit like openings (length: ~27.0 mm, width: ~5.0 mm) which the frogs used as portals. Males start calling early (around 16.00h) on rainy days, increase in number at dusk and subsequently last until around 22:00h. However, on two occasions, we heard them calling at 8:00 h in the morning. We observed that individuals reside only in live reeds. Specimens were found as pairs (a male and a female) in culms on two occasions, and solitarily in different culms and reed brakes at the type locality.
In subsequent field visits (29th May 2007) we observed an egg clutch with six developing embryos (Figure 1b) (diameter of eggs with jelly cover: 4.94 ± 0.06 mm, range: 4.87–5.01 mm) ensconced in jelly cover, attached to inner walls of hollow reeds, ~12 cm above the opening. Embryos were cream-white in color and had pigmented eyes with visible heart-beats and movements; which would eventually hatch into froglets as in other Philautus of the region (Gururaja & Ramachandra, 2006). This is similar to development mode 20 (Duellman & Trueb, 1994). Both males and females were in the same hollow reed, indicating the possible provisioning of parental care. However, this requires further field investigations to substantiate.
Advertisement call analysis : Calls were recorded using Olympus digital voice recorder (W–10, Olympus) within 10–20 cm from calling males. The air temperature and relative humidity were 93.75 ± 3.3 % (range: 90–98 %) and 21.76 ± 1.45°C (range: 20–23.6°C) respectively. Calls were recorded from four individuals, on two days. Six calls were analyzed using SIGVIEW32 Ver.1.9.3.2. Call terminology were based on Giacomo & Castellano (2001). Advertisement call had a short four pulse call (shriek ‘shreaaw’ note) and a long 27–73 pulse call (‘tink tink tink tink….’ notes). Average dominant frequency was 2796.82 ± 125.49 Hz (range: 2691.23–2978.56 Hz), Call duration was 5.42 ± 1.90 sec (range: 3.04–8.23 sec), short call pulse duration 0.22 ± 0.05 sec (range: 0.17–0.27 sec), short pulse rate 19.37 ± 4.37 sec–1 (Range: 14.83–24.24 Sec–1), long pulses were 48.33 ± 17.84 (range: 27–73), long call pulse duration 5.11 ± 1.92 sec (range: 2.74–7.94 sec), long pulse rate 9.47 ± 0.63 sec–1 (range: 8.52–10.21 sec–1). Figure 2 illustrates call spectrum and amplitude of a single advertisement call of 8.22 sec duration.
Comparisons : We compared the new species with all 22 known species from south India listed in Appendix- I. Sri Lankan and South-east Asian Philautus are excluded from comparison as they form phylogenetically distinct clades (Bossuyt et al. 2004; Manamendra–Arachchi & Pethiyagoda, 2005). However, the phylogenetic status of P. cf. leucorhinus and P. cf. variabilis is not fully resolved, and they were therefore included in morphological comparison. Morphometric and meristic data of type specimens were taken from the original description of the respective species (Table 2), additional information is compiled from subsequent publications as cited in Appendix–I. Philautus ochlandrae sp.nov. differs from all other Indian species of Philautus in a number of characters. Appendix–I provides the opposing suites of characters of these congeners compared to P. ochlandrae sp.nov.
Considering the morphological information of 17 male type specimens of Philautus, we performed a cluster analysis using STATISTICA software (version 5.5). This analysis was used to compare the new species with other known congeners, based on unweighted pair group averages and squared Euclidian distance measure of 19 morphometric and three meristic characters. We included only male type specimens for cluster analysis, hence P. tinniens and P. variabilis (with female type specimens) were excluded from the analysis. We also excluded P. beddomii, P. bombayensis, P. chalazodes, and P. travancoricus, for lack of data. From the dendrogram generated (Figure 3), despite a minor branching among the individuals of P. ochlandrae sp. nov., overall clustering clearly indicates the species to be new. There is an overlap of P. ochlandrae sp. nov. with P. griet, however, P. griet differs from P. ochlandrae sp.nov., in the following characters: dorsum brown with large spines; tongue without papilla; supernumerary tubercles on both fingers and toes; webbing on toes rudimentary; webbing transparent with black spots; vocal sac and throat light gray; thighs cross barred.
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