Ptychadena goweri 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 goweri Smith, Noonan & Colston, 2017

Type material.

Holotype. An adult male (TJC224) collected on 10 December 2012 by T. J. Colston in Katcha, Bale National Park, Ethiopia (6.71779°N, 39.72572°E, 2375 m a.s.l.). Paratypes. Three juveniles (XF781, XF782, XF783) collected 7 August 2011 by X. Freilich and S. Boissinot north of Hagere Mariam, Oromia, Ethiopia (5.8027°N, 38.2705°E, 2323 m a.s.l.). All type specimens and examined material are deposited at ZNHM.

Material examined.

In addition to the holotype, we examined one male (TJC218) collected by T. J. Colston, one female (15-85) and two males (15-103, 15-105) collected on 7 August 2015 by X. Freilich, J. Reyes-Velasco and S. Boissinot in the Harenna forest (6.5866°N, 39.7417°E, 1778 m a.s.l.), one male (15-121) collected on 7 August 2015 by X. Freilich, J. Reyes-Velasco and S. Boissinot in the Harenna forest (6.6634°N, 39.7302°E, 2002 m a.s.l.), one female (15-425) and two males (15-426, 15-427) collected on 27 September 2015 by X. Freilich, J. Reyes-Velasco and S. Boissinot northwest of Kibre Mengist (5.9055-6.04546°N, 38.837-38.9334°E, 1745-2238 m a.s.l.), two males (15-448, 15-449) collected on 28 September 2015 by X. Freilich, J. Reyes-Velasco and S. Boissinot in Harenna forest (6.71925 N, 39.7202 E), two males (SB99 and SB100) collected on 10 April 2018 by S. Goutte and J. Reyes-Velasco in the Harenna forest (6.6634°N, 39.7302°E, 2440 m a.s.l.), two females (SB158, SB159) and two males (SB160, SB161) collected on 17 April 2018 by S. Goutte and J. Reyes-Velasco northwest of Kibre Mengist (6.0093°N, 38.8576°E, 2105 m a.s.l.), one female (SB807) collected on 7 May 2019 by S. Goutte in the Harenna forest (6.6640°N, 39.7301°E, 1992 m a.s.l.), one female (SB808) collected on 10 May 2019 by S. Goutte in the Harenna forest (6.7164°N, 39.7257°E, 2375 m a.s.l.).

Diagnosis.

Large species (male (15) SVL 42.4 ± 2.7 mm, female (6) SVL 51.2 ± 4.2 mm) from the Ptychadena neumanni species group (Fig. 21 ) distinguished by the following combination of characters: (1) long hind limbs (male TL/SVL 0.60 ± 0.05, female TL/SVL 0.59 ± 0.02), (2) long feet (male FL/SVL 0.61 ± 0.05, female FL/SVL 0.58 ± 0.02), (3) long hands (male HAL/SVL 0.24 ± 0.03, female HAL/SVL 0.23 ± 0.01), (4) long head (male HL/SVL 0.38 ± 0.04, female HL/SVL 0.36 ± 0.04), (5) long snout (male SL/SVL 0.16 ± 0.02, female SL/SVL 0.15 ± 0.01), (6) vocal sacs light grey, cream or yellow, sometimes mottled with light grey, (7) male skin smooth.

Comparison.

Except for P. cooperi , the largest species of the Ptychadena neumanni complex. Body size alone distinguishes Ptychadena goweri from P. nana , P. robeensis sp. nov., P. levenorum , P. erlangeri , and P. doro sp. nov. Compared to the larger Ptychadena species of Ethiopian highlands, it has longer thigh, tibia, feet, hands, head, snout, and inter-orbital distance than P. delphina sp. nov., P. beka sp. nov., and P. amharensis . The light-colored vocal sacs of adult males distinguish P. goweri from P. beka sp. nov., P. delphina sp. nov., and P. neumanni and P. cooperi . The almost complete dorsal ridges distinguish further P. goweri from P. cooperi , which presents rows of short glandular folds on the dorsum.

Description of the holotype.

Relatively large (SVL 41.9 mm) male (Fig. 22 ) with long hind limbs (TL/SVL 0.58, Suppl. material 3: Table S3). Head as long as wide. Snout projecting beyond the lower jaw. Interorbital distance almost equal to the eye diameter. Internarial distance 0.88 × interorbital distance. Tympanum 0.85 × eye diameter. Finger tips not expanded but rounded, with moderate subarticular tubercles. Finger formula: I<II<IV<III. Hand free of webbing. Hindlimbs elongated, with tibia length 0.58 × snout-vent length. Foot slightly longer than thigh and tibia (FL/THL 1.14, FL/TL 1.05). Toe tips rounded. Subarticular tubercles small and round. Inner metatarsal tubercle present, external absent. Toe formula: I<II<V<III<IV. Foot webbing formula: Ie(1), IIi/e(1-1.5), IIIi/e(1.5-2), IVi/e(2-2), Vi(2). Two continuous lateral ridges, brown anteriorly and light brown posteriorly, barely visible, six interrupted dorsal ridges. No vertebral, nor sacral ridges. No wart on body or limbs. Tongue free for less than a third of its length, divided in two lobes. Vomerine, maxillary and premaxillary teeth present.

Coloration of the holotype in preservative.

Dorsal ground color brown with a few small, irregular oval dark brown blotches symmetrically distributed on the dorsolateral ridges. Wide light brown vertebral stripe, doubled with a thin, clearer stripe from the tip of the snout to the vent. Dark brown canthal stripe from the tip of the snout to the back of the jaw. Light vertical stripe on the otherwise brown tympanum. Upper and lower lip brown with irregular dark brown molting. Flanks grey anteriorly to light brown posteriorly with irregular dark brown blotches on the anterior half. Throat, ventrum, ventral side of the thighs and tibias uniformly cream with very light grey dusting on the throat. Two symmetrical dark brown blotches on the ventral side of the shoulders. Thin, barely visible, light longitudinal stripe on the tibias. Irregular and undefined brown markings on the thighs, tibias, and feet. Back of thighs molted light grey and brown. Vocal sacs mostly white, with slight grey dusting posteriorly.

Variations.

In life, background coloration varies from light brown, olive grey to dark brown. The vertebral stripe may be thin or wide doubled with a thin lighter stripe within it, and from cream to grey and light yellowish brown. The dark brown to black blotches on the dorsum vary in size and number but are always organized along the dorsal ridges. Some individuals present small, irregular black markings in between ridges. Dark markings on the flanks are quite variable between individuals, from a few large dark blotches to a multitude of smaller ones, covering mostly the antero-dorsal part of the flank. Dorsolateral ridges can be discontinued once or twice and can be cream, yellow, or brown-orange. Some individuals present a reddish-brown marking on top of the eyelid.

Iris bicolored, with upper third silver to golden and lower two thirds dark golden to dark brown. Cream or golden vertical blotch on the dark brown tympanum always present. The thin stripe on the tibia may extend on the thigh in some individuals. Forearms, thighs, tibias and feet are more or less clearly marked with dark brown bars. Vocal sacs always light in color (yellow, cream, or light grey), more or less dusted with grey on their dorsoposterior sides. Dorsal ridges may be more or less discontinuous.

Habitat, distribution, and natural history.

The distribution range of Ptychadena goweri is restricted to the southeast of the GRV, at elevation ranging from 1745 m to 2550 m a.s.l. The species is found in clearings in the Harenna forest, south of the Sanetti plateau, from Kibre Mengist to Irba Muda, and north of Hagere Mariam (5.8027- 6.7193°N, 28.2705°E). Males are found calling at night in shallow puddles in clearings or grassy meadows. Within the genus, Ptychadena goweri is found in sympatry with P. harenna , P. levenorum , P. neumanni , and P. erlangeri .

Advertisement call.

The call of Ptychadena goweri (4 males, 32 calls) is composed of a single pulsed note of 634 ± 74 ms in duration, containing 33.5 ± 2.9 pulses. Pulses are grouped by 3.3 ± 1.5 pulses within each note and increase in amplitude up to 404 ± 65 ms, after what the amplitude decreases. Within pulses groups, the first pulse has the lowest, while the second pulse has generally the greatest amplitude. Call repetition rate is highly variable and dependent on the social context. The individuals we recorded produced calls in “bursts”, where several males were forming a short chorus, spaced by long silent intervals. Call dominant frequency is 2318 ± 86 Hz with a slight increase in frequency within notes.

Within the P. neumanni complex, the call of P. goweri can be distinguished 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 (9 ± 2 ms within pulse groups) distinguish the call of P. goweri from those of P. robeensis sp. nov. and P. delphina sp. nov. The call of P. goweri can be further distinguished from those of P. nana and P. erlangeri by a longer duration.

Figures

Figure 21. Ptychadena goweri A Live male (SB 99; left) and female (SB 5807, right) B dorsal and ventral views of the same individuals (male left, female right) after euthanasia and before fixation.

Figure 22. Holotype of Ptychadena goweri. Dorsal and ventral views of the male holotype (TJC 224).