Nannophrys naeyakai, Fernando, Samantha Suranjan, Wickramasingha, Mendis & Rodirigo, Roshan K., 2007

Fernando, Samantha Suranjan, Wickramasingha, Mendis & Rodirigo, Roshan K., 2007, A new species of endemic frog belonging to genus Nannophrys Günther, 1869 (Anura: Dicroglossinae) from Sri Lanka, Zootaxa 1403, pp. 55-68 : 57-65

Nannophrys naeyakai sp. nov.

Holotype: NMSL 2004.12.1, SVL 39.30 mm, adult male, Kokagala hill (N 07° 24’ E 0 81 0 12’) Ampara district, Eastern province, Sri Lanka. Collected by S. S. Fernando & U. T. I. Abewardana, on 13 March 2004 ( Figs. 2­3 ).

Description of the holotype: SVL 39.30 mm, HL to SVL ratio 0.40. Head is broader than long, HW/HL ratio 1.14, depressed, HL/HD ratio 2.53. Snout gently rounded dorsally ( Fig. 2 ) and ventrally; smoothly rounded laterally ( Fig. 3 ). Nostrils dorso­lateral; nearer to tip of snout than to anterior corner of eyes, SN/NE ratio 0.46. Nasal capsule not elevated. Adult longitudinal internarial groove not deeper. Canthus rostralis smooth. Loreal region slightly concave. Symphysial knob hard, sharp, narrow, SKH 1.30 mm. Close pair of sharp apophyses, IAD 2.90 mm, height of symphysial knob less than two apophyses ( Fig. 4 ), SKH/AH ratio 0.80. Upper jaw with finely pointed teeth; vomerine teeth in two small series behind posterior level of choanae, no denticular processes. Edge of upper lip with slightly upward scallops. Tympanum distinct; rounded or slightly vertically oval, TW/TH ratio 0.87; horizontal diameter equal to half the diameter of orbit, TW/ED ratio 0.50, supratympanic fold prominent; extending from post orbits to base of fore limbs. Tip of the fingers and toes bluntly rounded ( Figs. 6 & 9 ). Fingers free; 1<2<4<3, each finger with a rounded or oval subarticular tubercle. Two palmar tubercles. Hind limbs webbing free, toes 1<2<5<3<4. Subarticular tubercles on toes moderately elongate; laterally elevated; prominent. Penultimate and distal subarticular tubercles on 4th toe distinctly separated and wider, DPL 1.30 mm, supernumerary tubercle smaller than penultimate subarticulr tubercle on 4th toe. Inner metatarsal tubercle distinct; elongate and compressed, outer metatarsal tubercle absent. Scattered, fine, white­ tipped dorsal tubercles on head, shoulder and limbs. Skin slightly rough postcranially. Granular, warty pustules on lateral body. Venter smooth. White­tipped tubercles on fore and hind limbs (knee and tarsus). No white­ tipped tubercles or pustules on tympanum.

Upper surface of the body is brown, embedded with yellow­white marbles in the live animal. Two yellowwhite cross bars on fore (upper arm & lower arm) and hind (femur, tibia and tarsus) limbs; the bars align when the hind limbs are folded. ( Figs. 2­3 ). Ventral is yellow­white without any markings. The description is relevant for both male and females.

Paratypes: NMSL 2004.12.2, SVL 43.60 mm, adult female, NMSL 2004.12.3, SVL 22.55 mm, juvenile female, NMSL 2004.12.4, SVL 35.90 mm, adult female, NMSL 2004.12.6, SVL 24.35 mm, adult male, Kokagala forest reserve (N 0 7 0 24’; E 81 0 12 ’) Ampara district, Eastern province, Sri Lanka. Collected by S. S. Fernando & U. T. I. Abewardana, on 13 March 2004. NMSL 2006.4.1, SVL 32.00 mm, adult female, NMSL 2006.4.2, SVL 29.50 mm, subadult female, NMSL 2006.4.3, SVL 30.15 mm, subadult male, Yakunhela (N 0 5 0 36’; E 0 79 0 58’), Bibile, Monaragala district, Uva province, Sri Lanka. Collected by S. S. Karunarathne & U. T. I. Abewardena on 14 July 2005; NMSL 2004.12.5, SVL 43.35 mm, adult female, Kokagala forest reserve (N 0 7 0 24’; E 81 0 12 ’) Ampara district, Eastern province, Sri Lanka. Collected by S. S. Fernando & U. T. I. Abewardana, on 13 March 2004.

Description of the paratypes ( Table 1 ): Adult male SVL 24.35­35.90 mm (SD ± 5.78), adult female, SVL 29.50­43.60 mm (SD ± 8.46). (all ratios measured by mean value of each length) HL to SVL ratio 0.41 (SD ± 0.02). Head is broader than long, HW/HL ratio 1.15 (SD ± 0.06), depressed, HL/HD 0.38 – 0.47 mm, (SD ± 0.03). Snout gently rounded dorsally and ventrally; smoothly rounded laterally. Nostrils dorso­lateral; nearer to tip of snout than to anterior corner of eyes, SN/NE ratio 0.44 (SD ± 0.09). Nasal capsule not elevated. Adult longitudinal internarial groove not deeper. Canthus rostralis smooth. Loreal region slightly concave. Symphysial knob hard, sharp, narrow, mean SKH 1.10 mm (SD ± 0.24). Close pair of sharp apophyses, IAD 2.30 mm (SD ± 0.39), height of symphysial knob less than two apophyses, SKH/AH ratio 0.81 (SD ± 0.07). Upper jaw with finely pointed teeth; vomerine teeth in two small series behind posterior level of choanae, no denticular processes. Edge of upper lip with slightly upward scallops. Tympanum distinct; rounded or slightly vertically oval, TW/TH ratio 0.83 (SD ± 0.08); horizontal diameter equal to half the diameter of orbit, TW/ED ratio 0.48 (SD ± 0.11), supratympanic fold prominent; extending from post orbits to base of fore limbs. Tip of the fingers and toes bluntly rounded both in juveniles and adults. Fingers free; 1<2<4<3, each finger with a rounded or oval subarticular tubercle. Two palmar tubercles. Hind limbs webbing free, toes N. neyakai N. marmorata N. ceylonensis

Male (n=3) Female (n=6) Female (n=5) Male (n=5) Female (n=1) 1<2<5<3<4. Subarticular tubercles on toes moderately elongate; laterally elevated; prominent in both juveniles and adults. Penultimate and distal subarticular tubercles on 4th toe distinctly separated and wider, 1.05 mm (SD ± 0.35), supernumerary tubercle absent or smaller than penultimate subarticulr tubercle on 4th toe. Inner metatarsal tubercle distinct; elongate and compressed, outer metatarsal tubercle absent. Scattered, fine, white­tipped dorsal tubercles on head, shoulder and limbs. Skin slightly rough post­cranially. Granular, warty pustules on lateral body. Venter smooth. White­tipped tubercles on fore and hind limbs (knee and tarsus) in both sex; juveniles and adults. No white­tipped tubercles or pustules on tympanum. Males with more whitetipped tubercles on dorsum. NMSL 2004.12.5 without supernumerary tubercle on 4th toe. Colour is same as the holotype description.

Diagnosis: Nannophrys naeyakai sp. nov. is distinguishable from all other Nannophrys species by the following combination of characters; distance between distal subarticular tubercle and penultimate subarticular tubercles on 4th toe (mean distance 1.05 mm (SD ± 0.35)) ( Fig. 8 ), palmar tubercle and subarticular tubercle on 1st finger well separated ( Fig. 6 ) and presence of a hard, sharp, narrow symphysial knob lower than two apophyses (mean SKH/AH ratio 0.81 (SD ± 0.07)) ( Fig. 4 ).

Comparison: N. naeyakai is morphologically very similar to N. marmorata . Both species have marbled markings on the dorsal surface but the former is clearly distinguished by the following taxonomic characters: distal subarticular tubercle and penultimate subarticular tubercles of 4th toe are well separated ( Fig.8 ) (vs. both tubercles close) ( Fig.9 ). Supernumerary tubercle absent or smaller than penultimate subarticular tubercle on 4th toe (vs. always present and comparatively large). A hard sharp narrow symphysial knob and a close pair of sharp apophyses on anterior edge of mandible, and symphysial knob lower than two apophyses ( Fig. 4 ) (vs. blunt wider symphysial knob and more wider pair of apophyes on anterior edge of mandible, and symphysial knob same height or higher than two apophyses) ( Fig. 5 ). Palmar tubercles comparatively smaller, inner palmar tubercle separated from outer palmar tubercle ( Fig. 6 ) (vs. palmar tubercles comparatively large, inner palmar tubercle connected with outer palmar tubercle) ( Fig. 7 ).

Two yellow­white cross bars on hind (femur, tibia and tarsus) limbs; the bars align when the hind limbs are folded ( Figs. 2­3 ). (vs. limbs with distinct marbled pattern no white bars).

In comparison with Nannophrys ceylonensis , average distance of eye to tympanum is low (ET/TW, 0.52 ratio) in N. naeyakai (vs. much larger in N. ceylonensis (ET/TW, 0.72 ratio). Additionally, a dorsally marbled marking is absent in N. ceylonensis and N. guentheri ; a character that distinguish both from N. naeyakai .

In 1874 Ferguson describe the species Trachucephalus ceylanicus similar to N. ceylonensis than N. marmorata and N. naeyakai . Recorded location of T. ceylanicus is Hewessa (“Hewisse” by Ferguson), which is a famous botanical collection locality in 18th century in south western Sri Lanka, is also under current distribution range in N. ceylonensis , not sympatric with N. marmorata and N. naeyakai .

Results of the principal component analysis (PCA) also show a clear separation of N. naeyakai from its relatives ( Fig. 10 ). Axis 1 and axis 2 explained majority of above characters to separate N. naeyakai and others ( Table 2 ).

Etymology: The species epithet, naeyakai , commemorates a common belief of the tribal people (Veddas) in the type locality area. Spiritual life after death (Devils) of Vedda relatives (referred to as “naeyakas”) protects the living tribesmen from environmental hazards and assists in daily activities according to the belief. These spirits are honoured and acknowledged by ritual dances performed by tribesmen time to time. English­ Sri Lanka Tribal Rock­frog; Sinhala­ Nae­yak Gal Para Mediya.

Ecology: The habitat of N. naeyakai include seasonal streams with rock crevices. During the wet season, the type locality was covered by grasses, dominated by Cymbopogon sp. ( Fig.11 ). The mean depth of the streams was 3 cm and at places 5­15 cm rock pools were formed. Rock crevices, boulders, masses of grass ( Cymbopogon sp.) roots and vegetation mats consisting of Utricularia , Eriocaulon and Xyris spp. were identified as microhabitats. The vegetation and the water source rapidly dried out by desiccating south­west monsoon winds in July­October. Bush fires were frequent during the dry period.

Behaviour: The new species was observed to be more active at night; during the day it was found hidden in the microhabitats. In the morning, individuals gathered on to the open vegetation mats of Utricularia to prey on insects attracted by flowers. Some frogs migrated to moist vegetation mats from exposed, dry rock surfaces during the evening.

Figures

FIGURE 2. Dorsal view of N. naeyakai. NMSL 2004.12.1; SVL 39.30 mm, holotype male.

FIGURE 3. Lateral view of N. naeyakai. NMSL 2004.12.1; SVL 39.30 mm, holotype male.

FIGURE 4. Anterior edge of the mandible ­ N. naeyakai; sharp & narrow symphysial knob. Height of symphysial knob less than two apophyses. NMSL 2004.12.1; holotype male.

FIGURE 5. Anterior edge of mandible ­ N. marmorata; blunt & wide symphysial knob and more wider pair of apophyes. Height of symphysial knob is the same or slightly higher than two apophyses. NMSL 2004.13. 4. SVL 29.59 mm, subadult female.

FIGURE 10. Results of principal component analysis (PCA); axis 1 and axis 2 show the separation of three species. Axis 1 illustrates, based on SVL, toe and finger lengths, that N. marmorata and N. naeyakai are differentiated; axis 2 illustrates, based on HD, HW, TW and knee angle to tip of tarsus, that N. ceylonensis and N. naeyakai are differentiated. N. naeyakai partially overlaps with N. ceylonensis on axis 1. Further, N. marmorata and N. ceylonensis are well separated on axis 2.

FIGURE 11. Habitat of N. naeyakai; NMSL 2004.12. 1 SVL 39.30 mm, holotype in Kokagala hill.

FIGURE 6 – 7. 6. N. naeyakai, NMSL 2004.12. 1 SVL 39.30 mm holotype, ventral aspect of right hand. 7. N. marmorata NMSL 2004.13. 4. SVL 29.59 mm, ventral aspect of right hand.

FIGURE 8 – 9. 8. N. naeyakai, NMSL 2004.12. 1 SVL 39.30 mm holotype, ventral aspect of right foot. 9. Right foot of N. marmorata NMSL 2004.13. 4. SVL 29.59 mm, ventral aspect of right foot.

Tables

TABLE 1. Morphometric data of N. neyakai in comparison of N. marmorata and N. ceylonensis.

N. neyakai			N. marmorata		N. ceylonensis
Male (n=3)	Female (n=6)		Female (n=5)		Male (n=5)	Female (n=1)
Mean S.D. Range Mean	S.D. Range	Mean	S.D. Range	Mean	S.D. Range	Length (mm)
SVL 30.11 5.78 24.35–35.90 35.04	8.44 22.55–43.60	42.33	7.19 29.60–46.30	27.81	5.76 24.70–36.45	44.95
% SVL
HL 41.39 0.96 40.41–42.33 41.34	2.79 37.80–44.90	39.78	0.88 38.9 –40.99	39.96	2.40 36.99–42.33	40.65
HW 47.39 1.45 45.87–48.76 47.54	1.55 45.54–49.94	46.17	0.50 45.65–46.84	42.56	1.47 40.70–42.30	48.05
HD 18.68 0.99 17.64–19.62 17.03	1.40 14.65–18.41	16.85	1.12 15.25–18.25	20.31	0.70 19.54–20.99	16.75
% HL
SM 89.94 4.90 85.32–95.11 89.52	3.72 84.11–94.48	88.08	3.07 85.07–91.84	87.16	6.37 78.25–93.40	82.30
SN 10.55 1.31 9.10–11.65 11.24	1.93 9.74–14.81	10.19	1.37 8.71–12.45	7.58	0.97 6.51–8.81	8.25
IN 22.36 4.24 17.52–25.44 19.44	1.02 18.05–20.63	18.80	1.97 17.59–21.93	19.03	1.62 17.06–21.04	17.90
NE 27.74 4.92 23.66–33.20 23.94	1.11 22.49–22.76	23.29	1.85 20.14–24.48	25.59	1.19 23.97–26.78	23.60
ED 51.99 30.36 32.83–86.99 32.95	1.90 30.62–35.50	34.39	0.96 33.57–35.57	37.39	1.35 36.37–39.24	32.80
IO 83.03 7.19 74.85–88.38 85.47	2.82 82.17–88.90	87.25	2.93 82.78–90.52	88.43	3.87 83.83–92.43	83.30
ST 71.19 8.39 61.55–76.84 74.20	2.53 71.78–79.00	74.54	0.99 73.64–76.18	73.89	4.55 68.24–79.38	74.35
NT 50.12 27.86 17.96–67.15 65.24	2.17 61.15–67.02	64.49	2.03 61.88–66.78	64.58	2.52 61.06–65.80	67.50
TW 18.48 0.56 18.41–19.07 16.70	1.15 15.15–18.47	17.92	1.93 14.79–19.70	14.17	1.30 12.99–16.02	15.15
TH 21.55 1.54 20.10–21.39 20.56	1.36 19.16–22.44	17.63	0.64 17.01–18.59	16.10	1.66 14.61–18.03	18.05
ET 8.61 1.40 6.99–9.46 9.15	1.84 7.25–11.57	10.51	2.03 7.50–13.12	11.07	1.98 8.44–13.28	15.30
IT 85.82 1.11 84.85–84.03 84.18	4.22 79.02–90.25	89.34	1.39 87.10–90.88	90.79	5.06 86.32–97.11	88.55
UA 42.89 3.02 39.51–45.35 39.33	1.81 36.90–42.30	42.26	4.01 38.07–48.80	40.45	1.93 37.83–42.44	43.10
LA 45.36 2.79 42.91–48.40 44.65	4.26 39.29–49.67	42.47	10.79 23.25–48.45	47.53	3.60 44.62–52.60	46.70
IF 33.00 1.35 31.55–34.21 30.54	2.31 26.52–32.82	34.53	1.22 32.40–35.42	34.84	2.71 32.64–38.80	39.55
2F 43.69 2.33 41.19–45.79 39.77	2.36 37.01–42.66	47.31	1.53 44.98–49.11	48.20	2.42 45.66–51.41	53.55
3F 59.96 1.95 58.73–62.21 55.76	2.27 52.06–58.28	61.39	1.42 59.13–63.32	66.14	2.53 55.73–63.73	69.25

TABLE 2. Characters, eigenvalues and percentage variation explained for the first two axes used in thirteen different morphometric characters of N. naeyakai, N. marmorata and N. ceylonensis.

Characters	Axis 1	Axis 2
SVL	­0.288	­0.275
HW	0.035	­0.394
HD	0.101	0.382
TW	­0.070	­0.335
IF	­0.325	0.147
2F	­0.345	0.225
3F	­0.282	0.307
KT	­0.090	­0.358
1T	­0.307	­0.288
2T	­0.380	­0.153
3T	­0.399	0.043
5T	­0.383	0.022
DPL	0.208	­0.329
Eigenvalues	5.585	4.196
% of variance explained	42.959	32.279