Ptenopus kenkenses, Becker & Alexander & Tolley, 2025

Ptenopus kenkenses sp. nov.

Figures 15 View Figure 15 , 16 View Figure 16 , 20 F View Figure 20

Common names.

Nama barking gecko

Nama: || en || ense / || en || enses (“ || ” = lateral click)

Afrikaans: Nama blafgeitjie

Chresonymy.

Ptenopus garrulus maculatus View in CoL (in part) – FitzSimons (1935: 525; Kanus), FitzSimons (1937 b: 160; Great Fish River), Mertens (1971; southern-central Namibia localities), Haacke (1975: 225; Great Karas Mountains, Keetmanshoop)

Ptenopus garrulus (in part) – Brain (1962 a: fig. 3; southeastern localities)

Comment.

All Ptenopus specimens that occur on compact substrates in the northern Nama Karoo, i. e., inland in the south of Namibia and from the Northern Cape (Great Karoo), are likely to be assignable to this species.

Holotype.

NMNW R 11389 , adult male, collected from farm Goris near Giants’ Playground, || Karas Region, Namibia ( –26.4538, 18.3097, 1106 m a. s. l.), by Francois S. Becker and Bertha Buiswalelo on 27 September 2022. GoogleMaps

Paratypes.

NMNW R 10839 ( adult female, allotype) and NMNW R 10841 ( adult male) collected from Koës , || Karas Region, Namibia ( -25.9364, 19.0869, 1000 m a. s. l.), by Francois S. Becker, Hileni Shivolo and Sisamu Baepi on 6 October 2020 GoogleMaps ; NMNW R 11388 , adult male, with the same collection details as the holotype GoogleMaps .

Additional material examined.

See Table S 1 for unvouchered photographed specimens (13), DNA samples (11 available, 7 sequenced), and call recordings (9) included (total n = 20 excluding types).

Etymology.

This species is named after the Nama name for the gecko, “ || en || enses ”, pronounced with two lateral clicks (produced by clicking with one’s tongue on the posterior-lateral roof of one’s mouth, similar to the typical command given for a horse to speed up), in reference to the clicking sound that it makes. The name is usually formed in the Nama female genitive, indicated by the suffix “ s ”, because the animal is small. This gecko occurs throughout the Nama Karoo and various places that were historically, and are currently, occupied by the Nama people. The Nama are highly familiar with its call, and believe the bite of this gecko to be extremely venomous. Nama children are taught to treat it with caution. However, the authors have been bitten by this species, and have survived.

We use the specific epithet “ kenkenses ”, a noun in apposition. Since the Nama symbols cannot be included in a scientific name, the phonetically similar letter “ k ” is used instead. However, the use of Nama lateral clicks is recommended in the pronunciation of this name.

Diagnosis.

A medium-sized Ptenopus ( SVL max. 58 mm, mean 51.3 mm, n = 10) with a short tail ( TL 65 % [range 60–72] of SVL, n = 7) and a stout appearance. It is distinguished from P. kochi , P. carpi , and P. sceletus sp. nov. by the following characters: Toes being intermediately fringed laterally (vs. weakly fringed in P. carpi and P. sceletus sp. nov. and extensively fringed in P. kochi ); having MBSR ~ 162, range 158–169 (vs.> 180 in P. kochi and < 135 in P. carpi and P. sceletus sp. nov.); by dorsal colour pattern being characterised by large, paired, light, subsymmetrical ovoid markings interspaced with or dominated by dense, dark brown mottled patches (vs. more finely spotted pattern in P. kochi and banded pattern in P. carpi and P. sceletus sp. nov.). It is further distinct from P. carpi and P. sceletus sp. nov. by the nasals being more swollen and the nostrils partially covered by internal projections of the upper labials; from P. kochi by having fingers laterally fringed with pointed triangular scales (vs. elongated pointed scales in P. kochi ) and having entire ventrum covered in white / cream ventral scales with some dark brown / grey specking (vs. pink, unpigmented patches on the limbs and tail of P. kochi ).

From congeners previously included in ‘ P. garrulus ’ it is distinguished by: Having a generally smaller internasal scale with higher IN / INSBB (median 7.4, range 5.6–11.0, n = 12), than P. circumsyrticus sp. nov. (usually <5.6); having a broader rostral with higher RB / RH (median 1.21, range 0.98–1.42, n = 12) than P. australis sp. nov. (<0.98); having generally higher MBSR (≥ 147) than P. australis sp. nov., P. circumsyrticus sp. nov., and P. maculatus (usually <147 except some P. circumsyrticus sp. nov.); having 2 or fewer internasal scales in contact with the rostral, while P. australis sp. nov. has three; colour pattern distinct from P. garrulus in having 4–5 large and distinctive paired, light, ovoid markings interspaced by distinct dark mottled patches usually touching the light markings (vs. more rows of and smaller white spots and overall more speckled pattern in P. garrulus ), and ovoid patterning on ventro-lateral portions of the face being more distinctive (vs. indistinct or absent in P. garrulus ).

Holotype description.

(Fig. 15 View Figure 15 ). Adult male, SVL 51.41 mm with original tail 30.61 mm (59.54 % SVL). Body and head covered with minute hexagonal to round scales of a similar size, dorsally and ventrally, with scales on limbs notably larger. Small mid-ventral incision for removal of liver sample. Body slender, MBSR 166, IOS 48, HL 15.97 mm, HW 11.15 mm, HH 6.85 mm, EED 5.93 mm. Upper labials 6 enlarged, with 4–5 small granules up to the angle of the jaw, lower labials 8, the posterior scale elongate and thin, and six granules bordering the mental. Clear but not prominent superciliary ridges tapering from above mid-eye level. Around the eye is a single row of elongated scales around the anterior, dorsal, and posterior margins, but more rounded and smaller along the ventral margin. Nasal scales slightly swollen, the prenasals barely separated by one small, rounded internasal scale in meagre contact with the rostral, with IN / INSBB 8.71, INSH / NB 1.03. Nostrils partially covered by projection from the upper nasal. Rostral broad, with RB / RH 1.42, MB / RB 0.75. Pupil vertical, EYE 3.46 mm. Ear opening is oblique (~ 45 °) and narrow with small projecting scales at the anterior margin. The neck region behind the cheeks is slightly swollen with internal calcium deposits. Arms, legs, and tail stout in appearance. Toes elongate, flattened, with moderately elongate fringed scales, small, pointed, triangular fringes on the fingers; strong nails on fingers and toes, being larger and thicker on the fingers.

Colouration.

In life, the holotype and similar paratype NMNW R 11388 (Fig. 16 A and C View Figure 16 ) has a dorsal background colour of light brown with orange, cream, and beige spots, with five intermediate paired, circular, markings on the neck and back interspaced by larger dark brown, irregular markings and some smaller cream dots and dark blotches that are more-or-less symmetrically scattered across the dorsal surface; the paired cream markings merge into bands on the tail (somewhat asymmetrical in the mid-tail) interspaced by 10–11 dark bars, which are barely noticeable on the nearly white tail tip; prominent dark brown to black dorsolateral markings; ventrum is immaculate white except for some dark grey mottling laterally, on ventral leg surfaces, and substantial dark mottling on (hand / foot) palms / soles. Extensive, bright yellow gular patch with faded anterior edges and a clear but speckled posterior edge, with a large white area on the throat; the bright yellow does not extend onto the lateral surfaces of the head, body, or onto the limbs. The iris is dark beige / light yellow-brown.

In preservative (Fig. 15 View Figure 15 ), the lighter colours have faded to off-white or beige, while the darker colours remain shades of dark brown or grey, and the orange and yellow have faded completely. The iris is a milky blue-grey.

Variation.

Refer to Table S 1 and Figure 4 View Figure 4 for range of morphometric characters, including the paratypes. While morphometric characters are relatively similar across all specimens, the colour patterns vary substantially, usually matching the local substrate (Fig. 16 View Figure 16 ). Background dorsal colouration variations include brown, light orange, beige, or red-brown; some amount of orange speckling is usually present, particularly in the western populations. Ventrally, animals are immaculate white with grey or brownish speckling clearly visible on (hand / foot) palms / soles. Males have bright yellow gular patches, while some male specimens also have yellow on the anterior or dorsal surfaces of the hind leg.

Advertisement call.

The advertisement call (Figs 3 View Figure 3 , 20E View Figure 20 ) consists of 4.6 notes (range 4–5), uttered slowly at a rate of 2.45s - 1 (range 1.99–2.96). Note duration is the longest of all species (92 ms [range 61–154]), the first usually notably longer than those following, with note 1 duration deviance 30 % [range 10–47]. Inter-note intervals are 316 ms (range 269–368) and quite regular, inter-note interval range 23.3 % (range 12–42). Median call density is high, 0.29 (range 0.18–0.48). Call duration is 1.57s (range 1.3–1.9). The basal frequency is ~ 399 Hz (range 366–474), but very soft may be inestimable, with harmonic bands louder towards the dominant frequency at 3.506 kHz (range 3.3–3.8); sometimes a very slight lower frequency peak is evident at around or just below half the dominant frequency (roughly 1.2–1.9 kHz, cannot always be reliably estimated). Frequency appears to modulate down by ~ 0.4 kHz during the course of the note, and (human) perceived pitch also seems to modulate within each note, slightly reminiscent of dripping water. Bandwidth (90 %) is difficult to estimate consistently: approximately 0.5–6.9 kHz.

Calling activity for this species commences ~ 30 min before sunset and may continue late into the night if the moon is up. Call period (mean 84 s) varies considerably, but can be as low as 18 seconds during peak chorus activity. Peak calling activity occurs from September to November.

Habitat and distribution.

This species occurs on consolidated soils such as gravel, alluvial silt, or compacted sandy soils throughout the northern Nama Karoo: southern Namibia and probably the Northern Cape, South Africa (Fig. 5 View Figure 5 ). The exposed rocky surfaces of the Nama group sedimentary formation in central-southern Namibia appears to bisect its distribution. The northeastern edge of its range is the western edge of the Kalahari Sand Sea, as it does not occur on loose sand. There is only one confirmed record from South Africa near Onseepkans, Northern Cape, but similar soils occur more broadly throughout large parts of the Northern Cape Province.

It has not been recorded in sympatry with any other species but occurs parapatrically to P. garrulus near Koës, Namibia (with P. garrulus occurring in the Kalahari Sand Sea), and in the Northern Cape, South Africa (where patches of Kalahari sand occur on more consolidated soils). It has been recorded ~ 40 km from the nearest confirmed P. adamanteus sp. nov. record in the west, and no closer than ~ 60 km from the nearest confirmed P. circumsyrticus sp. nov. record in the northwest of its range.

Natural history.

Calling (and therefore breeding) activity appears to be seasonal, probably peaking in the austral spring and early summer. This species is seldom found on the surface, except early in the evening during peak chorus activity. Burrow entrances are nearly always sealed after calling ceases, or during the day; the entrance is sealed from the inside, and it is so neatly disguised as to be almost entirely indistinguishable from the surrounding soil surface. The burrow is then re-opened before calling commences. It has been observed consuming large numbers of harvester termites ( Hodotermes mossambicus ), even up to 61 % of its own body-weight, during sporadic events when these termites emerge en masse to forage ( Bauer et al. 1989). All adult females collected by Bauer et al. (1989) in early October contained ovarian or unshelled oviductal eggs, suggesting an egg-laying period possibly later than November. One individual of P. kenkenses sp. nov. has been found to be infected by a tapeworm of the genus Mesocestoides ( McAllister et al. 1995) .

Aggregations of this species are sometimes observed on tarred roads late at night, numbering in the hundreds on a few kilometres of road. The reason for this behaviour is unknown.