Bioacoustics of Raorchestes ochlandrae

Va r ia ti o n : 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. TABLE 1 Morphometric (in mm) and meristic data for the type series of Philautus ochlandrae sp. nov. Prefix ZSI/WGFRS/V/A/ for all Holotype and Paratypes . For abbreviations see text. Parameters SEX Holotype 632 Male Paratype 633 Male Paratype 634 Male Paratype 635 Male Paratype 637 Male Average ± SD (Range) Paratype 636 Female SVL EL EN 25.6 2.9 1.9 22.1 2.8 2.1 23.2 3.0 2.1 24.7 3.1 2.0 24.5 3.3 1.9 24.0±1.38 (22.1–25.6) 3.0±0.18 (2.8–3.3) 2.0±0.07 (1.9–2.1) 23.3 3.1 2.0 HL HW HD 6.4 8.6 3.9 6.0 8.2 3.3 5.9 7.8 3.3 6.1 8.5 3.1 6.3 8.0 2.8 6.2±0.23 (5.9–6.4) 8.2±0.33 (7.8–8.6) 3.3±0.38 (2.8–3.9) 6.1 8.3 3.8 IBE IFE IN 7.7 4.0 1.7 7.2 3.5 1.6 7.3 3.6 1.4 7.6 4.2 2.0 7.6 4.1 1.6 7.5±0.20 (7.2–7.7) 3.9±0.30 (3.5–4.2) 1.7±0.23 (1.4–2.0) 7.7 4.5 1.9 IUE MBE MFE 2.8 1.9 4.7 2.8 1.8 4.2 2.5 2.0 4.7 3.0 1.7 4.1 2.6 1.9 4.2 2.7±0.19 (2.5–3.0) 1.8±0.10 (1.7–2.0) 4.4±0.32 (4.1–4.7) 2.9 1.5 4.0 MN NS SL 6.5 0.8 2.9 5.5 0.9 2.6 5.9 0.7 2.8 6.4 0.9 3.0 5.8 1.2 3.0 6.0±0.39 (5.5–6.5) 0.9±0.19 (0.7–1.2) 2.8±0.15 (2.6–3.0) 5.8 0.9 3.1 TYD TYE UEW 1.4 0.6 1.9 1.0 0.8 1.6 1.2 0.6 1.8 1.2 0.6 1.8 0.9 0.6 1.9 1.1±0.17 (0.9–1.4) 0.6±0.09 (0.6–0.8) 1.8±0.14 (1.6–1.9) 1.0 0.8 1.7 fd1 0.8 0.7 0.7 0.7 0.8 0.7±0.07 (0.7–0.8) 0.9 fd2 1.1 0.9 1.1 1.0 1.1 1.0±0.10 (0.9–1.1) 1.1 fd3 1.4 1.2 1.4 1.3 1.5 1.3±0.10 (1.2–1.5) 1.4 fd4 1.4 1.2 1.2 1.2 1.3 1.3±0.11 (1.2–1.4) 1.3 fw1 0.5 0.6 0.6 0.6 0.6 0.6±0.04 (0.5–0.6) 0.6 fw2 0.6 0.9 0.8 0.7 0.7 0.8±0.11 (0.6–0.9) 0.9 fw3 0.9 0.9 0.9 0.9 1.1 0.9±0.07 (0.9–1.1) 1.0 fw4 0.8 1.0 0.8 1.0 0.8 0.9±0.12 (0.8–1.0) 0.9 ......continued 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. Parameters Holotype 632 Paratype 633 Paratype 634 Paratype 635 Paratype 637 Average ± SD (Range) Paratype 636 FFL 1.7 1.4 1.4 1.6 1.4 1.5±0.13 (1.4–1.7) 1.6 SFL 2.2 1.9 2.0 2.3 1.8 2.0±0.19 (1.8–2.3) 2.3 TFL 4.0 3.8 3.8 4.3 3.7 3.9±0.23 (3.7–4.3) 4.0 FrFL 3.4 2.8 2.9 3.3 3.1 3.1±0.25 (2.8–3.4) 2.9 HAL 7.0 6.0 7.0 7.1 6.1 6.6±0.54 (6.0–7.1) 7.4 FLL 4.4 4.9 4.8 4.9 5.3 4.8±0.33 (4.4–5.3) 5.4 AG 12.7 9.8 11.1 11.4 13.5 11.7±1.42 (9.8–13.5) 7.8 BWBS 8.2 7.6 7.1 5.9 7.8 7.3±0.89 (5.9–8.2) 7.9 BWFL 4.1 4.8 4.1 3.7 4.1 4.2±0.37 (3.7–4.8) 5.0 FL 10.4 9.5 9.7 11.1 9.9 10.1±0.61 (9.5–11.1) 10.4 FW 3.6 2.9 3.8 3.5 3.5 3.5±0.30 (2.9–3.8) 3.3 TL 10.1 10.1 10.1 11.3 11.3 10.6±0.63 (10.1–11.3) 11.4 TW 3.4 3.6 3.3 3.2 2.8 3.2±0.30 (2.8–3.6) 3.2 FOL 9.5 8.8 9.2 10.5 9.4 9.5±0.63 (8.8–10.5) 9.9 TFOL 14.9 14.8 15.0 16.3 14.6 15.1±0.69 (14.6–16.3) 16.4 T1L T2L T3L T4L T5L td1 td2 td3 td4 td5 tw1 tw2 tw3 tw4 tw5 IMT 1.5 2.0 3.6 5.4 4.1 0.8 1.0 1.3 1.5 1.5 0.7 0.7 0.8 0.9 0.9 0.8 1.5 2.0 3.2 5.3 4.3 0.8 0.9 0.9 1.1 1.2 0.6 0.8 0.8 0.8 0.8 0.8 1.5 1.9 3.3 5.0 3.7 0.7 1.0 0.9 1.1 1.1 0.5 0.6 0.9 0.7 0.8 0.9 1.6 2.3 3.7 6.0 4.1 0.9 0.9 1.1 1.1 1.3 0.7 0.8 0.8 1.0 0.9 0.8 1.4 1.8 3.3 5.6 3.7 0.8 0.8 1.1 1.4 1.2 0.6 0.8 0.8 1.0 0.7 0.7 1.5±0.07 (1.4–1.6) 2.0±0.18 (1.8–2.3) 3.4±0.22 (3.2–3.7) 5.5±0.39 (5.0–6.0) 4.0±0.26 (3.7–4.3) 0.8±0.05 (0.7–0.9) 0.9±0.07 (0.8–1.0) 1.1±0.16 (0.9–1.3) 1.2±0.16 (1.1–1.5) 1.3±0.14 (1.1–1.5) 0.6±0.09 (0.5–0.7) 0.7±0.10 (0.6–0.8) 0.8±0.05 (0.8–0.9) 0.9±0.14 (0.7–1.0) 0.8±0.08 (0.7–0.9) 0.8±0.06 (0.7–0.9) 1.8 2.4 3.8 5.5 4.3 0.8 1.1 1.3 1.3 1.3 0.7 0.8 0.9 1.1 1.1 0.9 FFTF 3.9 3.6 3.6 3.9 3.7 3.7±0.16 (3.6–3.9) 4.3 MTFF 5.5 6.1 5.8 7.1 5.4 6.0±0.68 (5.4–7.1) 6.7 MTTF 5.5 5.4 5.4 6.1 4.9 5.4±0.42 (4.9–6.1) 5.9 TFTF 4.4 3.9 3.1 4.3 3.7 3.9±0.52 (3.1–4.4) 4.1 DBL 16.2 15.2 13.9 14.6 15.0 15.0±0.85 (13.9–16.2) 13.8 DBW 2.3 2.0 2.1 1.7 2.2 2.1±0.23 (1.7–2.3) 2.1 DBDB 4.5 4.5 4.0 4.7 4.4 4.4±0.25 (4.0–4.7) 4.5 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 1 b) (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. Species 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 SVL 23.8 21.3 29 20.5 29.4 22.3 22.6 21.3 27 27.8 29.9 34 35.9 31.5 25 18.2 37.2 28.3 HAL 6.3 5.5 8.7 6.3 8.8 6.2 7 6.3 7.1 7.5 8.2 10.6 10 8.8 6.9 4.5 10.5 7 TFL 3.7 3 5.9 3.1 5.2 3.2 4.2 4.5 5.3 4.8 4.7 6.3 6.3 5.5 4.9 3.4 6.5 5.2 EL 3.1 3.5 3.7 2.8 3.9 3.8 4 2.6 4.4 3.8 4.1 4.4 4.4 4.1 2.8 2.3 5 4.1 EN 2.1 1.4 2.1 1.7 2.6 1.7 1.9 1.3 3.1 3.7 2.8 3.5 3 2.8 1.9 1.4 3 2.1 HW 9 9.3 10.7 8.6 11.8 9.4 9.6 7.6 9.9 10.2 10.8 13.7 14.7 12 9.3 6.6 14.9 9.6 HL 9.2 8.2 10 8.5 10.4 8.5 9.2 7 9.1 7.7 9 12.6 13.1 11.6 8.6 4.5 13.1 10.1 NS 1 1 1.3 1.4 0.8 1.2 1.4 0.9 1.4 2 1.4 1.6 1.8 1.5 0.9 1.1 1 1.1 IN 2.1 2.5 3.1 2 2.8 2.6 2.3 2.1 2.6 2.8 2.4 3.2 3.3 3.2 2.3 1.8 3.2 3 IUE 2.5 4 3.5 2.7 3.7 3.3 2.8 2.5 3.2 3.4 3.8 3.2 4 4 3 2.4 4.4 3.3 TYD 1 0.8 1.3 1.6 1.4 1.1 1.2 1 2.3 1.4 0 2 1.5 1.7 1.2 1 1 2.1 UEW 2.4 1.6 2.7 1.8 2.6 2 2.7 2 2.3 2.5 2.2 3.2 3.1 2.9 2 1.7 3.3 2.5 FL 10.8 12 13.3 9.4 13.5 11.1 12.8 9.2 14 13.2 15.1 17.1 18 14.2 10.2 9.3 17.2 12.9 TL 11.6 11.2 12.7 9 13.5 10.9 11.6 9.3 13.7 13.5 14.3 17.1 17.4 15 9.9 9 17.7 13.4 FOL 8.9 9.2 12.3 8 12.3 8.9 9.3 8.9 10.7 10.6 12 14.3 14.6 13.1 10.2 7.1 16.2 11.8 T1L 1.7 1.8 2.7 1.9 3 2.1 2 2 2.4 2. 2 3.4 3.5 3 2.6 1.4 4 2.4 T4L 4.4 4.3 6.3 3.8 5.8 4.5 5.1 5.4 6.5 6.7 7 8.8 7.7 6.3 5.6 4.1 8.3 6 TFOL 13.3 15.1 19.3 11.8 19.4 14.2 15.4 13.4 16.8 17.7 19.8 23.1 24 19.9 16.4 11.6 24.7 17.8 IMT 0.8 0.8 1.1 0.9 1.2 1 1.1 0.8 0.9 0.9 0.9 1.7 1.4 1.4 1 0.8 1.6 1.1 STF 1 0 1 1 1 1 1 1 1 1 0 1 1 0 1 1 1 1 LP 0 0 0 0 1 0 0 0 0 0 0 1 1 1 1 0 0 0 WF 0.3 0.8 0.5 0.3 0.5 0.5 0.3 0.2 0.5 0.3 0.5 1 0.5 0.5 0.3 0.2 0.5 0.5 SEX Male Male Male Male Male Male Male Male Male Male Male Male Male Male Female Male Female Male Note: For abbreviations see text. Species 1. P . anili ; 2. P . bobingeri ; 3. P . charius ; 4. P . dubois ; 5. P . flaviventris ; 6. P . glandulosus ; 7. P . graminirupes ; 8. P . griet ; 9. P . cf. leucorhinus ; 10. P . luteolus ; 11. P. neelanethrus ; 12. P . nerostagona ; 13. P . ponmudi ; 14. P . signatus ; 15. P . tinniens ; 16. P . tuberohumerus ; 17. P. variabilis ; 18. P . wynaadensis . STF: present = 1, absent = 0; LP: present = 1, absent = 0, WF: 0.2 = reduced, 0.3 = partial, 0.5 = medium, 0.8 = nearly full, 1.0 = full.