Ptychadena levenorum Smith, Noonan & Colston, 2017

Goutte, Sandra, Reyes-Velasco *, Jacobo, Freilich, Xenia, Kassie, Abeje & Boissinot, Stephane, 2021, Taxonomic revision of grass frogs (Ptychadenidae, Ptychadena) endemic to the Ethiopian highlands, ZooKeys 1016, pp. 77-141 : 77

Ptychadena levenorum Smith, Noonan & Colston, 2017

Type material.

Holotype. Male, TJC219, collected in Katcha, Bale Moutains National Park, Ethiopia (6.7165°N, 39.7248°E, 2326 m a.s.l.) by T. Colston on 8 December 2012. Paratypes. XF923 and XF927, collected by X. Freilich and S. Boissinot on the 9 August 2011 west of Dinsho (7.1112°N, 39.7430°E, 3024 m a.s.l.). All type specimens and material examined are deposited at ZNHM.

Material examined.

Beside the male holotype (TJC219) we examined one female (15-155) and one male (15-158) collected by X. Freilich, J. Reyes-Velasco, and S. Boissinot on 9 August 2015 east of Dinsho (7.1061°N, 39.8181°E, 3058 m a.s.l.), one female (15-482) collected by X. Freilich, J. Reyes-Velasco and S. Boissinot on 3 October 2015 south of Dodola (6.8465°N, 39.1933°E, 3404 m a.s.l.), one female (16-89) and one male (16-90) collected by J. Reyes-Velasco and S. Boissinot on 10 July 2016 east of Dinsho (7.1065°N, 39.8184°E, 3065 m a.s.l.), one male (SB43) collected by S. Goutte and J. Reyes-Velasco on 6 April 2018 south of Dodola (6.8632°N, 39.1948°E, 3260 m a.s.l.), two males (SB66 and SB67) collected by S. Goutte and J. Reyes-Velasco on 8 April 2018 south of Dinsho, one female (SB85) and two males (SB90 and SB94) collected by S. Goutte and J. Reyes-Velasco on 9 April 2018 east of Dinsho.

Diagnosis.

A small species (male (8) SVL 34.3 ± 2.3 mm, female (4) SVL 37.0 ± 2.5 mm) of the Ptychadena erlangeri species group (Fig. 13 ) with variable coloration, distinguished by the following combination of characters: (1) short hindlimbs (male TL/SVL 0.49 ± 0.06, female TL/SVL 0.51 ± 0.04), (2) head as long as wide, (3) snout short (male SN/SVL 0.13 ± 0.02, female SN/SVL 0.13 ± 0.01), (4) vocal sacs cream, light grey, or bicolored cream and grey.

Comparison.

Smaller than P. goweri , P. delphina sp. nov., and P. cooperi and larger than P. nana and P. robeensis sp. nov. Snout shorter than all species of the P. neumanni complex except for P. nana , P. robeensis sp. nov., and P. erlangeri . Inter-orbital and eye-nostril distances shorter than P. erlangeri . Thigh and tibia of P. levenorum are shorter than those P. erlangeri , P. doro sp. nov., P. harenna , P. goweri , and P. neumanni , and longer than those of P. nana and P. robeensis sp. nov. Shorter feet than P. neumanni and P. doro sp. nov. Shorter hands than P. amharensis . Tympanum larger than in P. nana and P. robeensis sp. nov.

Description of the holotype.

Small sized (SVL 33.3 mm) male (Fig. 14 ). Head longer than wide (HW/HL 0.93). Snout slightly rounded, projecting beyond the lower jaw. Interorbital distance shorter than eye diameter (IOD/ED 0.78) and internarial distance (IOD/IND 0.93). Nostril closer to the eye than the tip of the snout. Tympanum 0.72 × eye diameter. Finger tips not expanded but rounded. Finger formula: I<II<IV<III. Hand free of webbing. Hindlimbs moderately long, with tibia length 0.54 × snout-vent length. Thigh shorter than tibia. Foot 1.3 × tibia length. Toe tips rounded. Inner metatarsal tubercle present, outer absent. Toe formula: I<II<V<III<IV. Foot webbing formula (toe internal/external sides, number of phalanges webbed): Ie(1), IIi/e(1-1.5), IIIi/e(1.5-2), IVi/e(2-2), Vi(2). Four discontinuous dorsal ridges and two discontinuous cream lateral ridges.

Coloration of the holotype in preservative.

Dorsal ground color brown with few small irregular oval dark brown blotches symmetrically distributed on the dorsolateral ridges. Very faint wide light grey-brown vertebral stripe from the tip of the snout to the vent. One faint interrupted dorsolateral cream ridge on each side. Dark brown canthal stripe from the tip of the snout to the back of the jaw. Upper lip cream dusted with brown and with irregular dark brown markings. Flanks cream with a few large and irregular dark brown spots. Throat, ventrum, ventral side of the thighs and tibias uniformly cream without any melanization, except for a couple of small irregular brown blotches on the upper ventrum. Barely visible dark brown bars on the tibias and feet. Irregular dark brown markings on the thighs, arms and forearms. Back of the thighs light brown marbled dark brown. Tympanum uniformly dark brown. Vocal sacs cream with some grey markings.

Variations.

Ptychadena levenorum shows important variations in coloration. In life, dorsum coloration varies from light yellowish brown to dark reddish brown, dark brown and bright green. All specimens examined had black blotches distributed symmetrically on the dorsal ridges, and for some of them the blotches were black with a green iridescence. A few additional dark brown or black blotches are found in the anterior part of the flanks. A vertebral stripe is always present, either thin, medium, or wide and may be cream, yellow, pale brown or bright green.

Iris bicolored, the upper third silver to golden and lower two thirds dark brown. Upper and lower jaws white to golden with few irregular light grey or brown markings but no barring. All specimens examined featured a dark brown or iridescent green canthal stripe from the tip of the snout to the back of the upper lip. Tympanum dark brown, sometimes with golden-iridescent green undefined blotch or dusting. A thin cream or green longitudinal stripe on the tibia is present in some individuals and may extend to the foot and to part or the entire length of the thigh. Tibias, thighs and feet more or less visibly barred with dark brown. Thighs posteriorly dark brown marbled with yellow. Ventrum and throat uniformly white to light yellow. Vocal sacs cream or light grey, very rarely with a bit of grey anteriorly. Small warts over the body and forelimbs present in 40% of adult males examined.

Habitat, distribution, and natural history.

The relatively restricted distribution range of Ptychadena levenorum extends on both the northern and southern sides of the Sanetti plateau (6.72-9.42°N, 38.66-39.82°E), although there is no record of its presence on the plateau itself. This species occurs mostly at elevation higher than 3000 m a.s.l. (3015 to 3404 m a.s.l.), except for the population living at the type locality Katcha (6.72°N, 39.72°E, 2410 m a.s.l.). The westernmost population was found south of Dodola, near Garamba (6.86°N, 39.19°E, 3260 m a.s.l.).

Individuals have been found, generally in small numbers, calling at night from shallow puddles in grassy meadows or forest clearings. Within the genus, this species is found in sympatry with Ptychadena cooperi and P. robeensis sp. nov. in the northern part of its range, and Ptychadena harenna and P. goweri at the type locality. Genetic analyses have shown that P. levenorum and P. robeensis sp. nov. hybridize where their ranges overlap.

Advertisement call.

The call of Ptychadena levenorum (2 males, 30 calls) is composed of a single pulsed note of 465 ± 98 ms in duration, containing 23.5 ± 4.3 pulses. Within a call, pulses are grouped, with 4.1 ± 1.5 pulses per group and sometimes with a lower-amplitude single pulse between pulse groups. The duration of inter-pulse intervals within pulse groups is 12 ± 2 ms. Call peak frequency is 2223 ± 90 Hz.

The call of P. levenorum differs from those of P. cooperi , P. amharensis , P. doro sp. nov. and P. neumanni (type A and B) by the distinguishable pulses composing the calls. Grouped pulses and short inter-pulses intervals distinguish the call of P. levenorum from those of P. robeensis sp. nov. and P. delphina sp. nov. The call of P. levenorum can be further distinguished from those of P. nana and P. erlangeri by a longer duration and from P. goweri by a shorter duration and fewer pulses.

Figures

Figure 13. Ptychadena levenorum A live male (SB 90; left) and female (SB 85, right) B dorsal and ventral views of the same individuals (male left, female right) after euthanasia and before fixation.

Figure 14. Holotype of Ptychadena levenorum. Dorsal and ventral views of the male holotype (TJC 219).