Ancylodactylus kituiensis, Malonza & Bauer, 2022

Malonza, Patrick K. & Bauer, Aaron M., 2022, Resurrection of the African gecko genus Ancylodactylus Müller, 1907 (Squamata: Gekkonidae) and description of six new species from Kenya, Zootaxa 5141 (2), pp. 101-139 : 110-116

Ancylodactylus kituiensis sp. nov.

Kitui Forest Gecko

( Figures 4–5 )

Cnemaspis africana (part) Spawls et al. 2018:78.

Holotype. NMK-L2702/2, adult male, Mutha Hill , Kitui South, Kenya (01.77512° S, 38.40588° E; 1300 m elevation), collected 6 October 2004 by Patrick K. Malonza & Joash O. Nyamache

Paratypes. NMK-L2702/1, adult female, same data as for holotype; NMK-L2744/1, adult male, Itiani Spring , Endau Hill , Kitui East , Kenya (01.24883° S, 38.54122° E; 772 m), collected 9 April 2005 by Victor D. Wasonga & Joash O. Nyamache; L2708/1, adult female, Itiani Stream Spring, Endau Hill, Kitui East, Kenya (01.23710° S, 38.54608° E; 800 m elevation), collected 13 October 2004 by Patrick K. Malonza & Joash O. Nyamache; L3559/1, adult male and L3559/5, adult female, Nzambani Rock, Kitui Central, Kenya (01.42645° S, 38.05622° E; 1145 m), collected 18 December 2014 by Patrick K. Malonza; L3780/ 1 adult male, Kaita Village , Mutomo in Kitui South , Kenya (01.77571° S, 38.34748° E; 846 m) collected 7 June 2016 by Victor Wasonga , Jacob M. Ngwava, Hesborn Nyambati & Daniel Kinaa Mutui; L3775/4, adult male, Mutomo Hill, Kitui South, Kenya (01.84515° S, 38.21529° E; 959 m), collected 9 June 2016 by Victor Wasonga, Jacob M. Ngwava, Hesborn Nyambati & Daniel Kinaa Mutui .

Diagnosis. A medium to large-sized Ancylodactylus with both sexes reaching about 50 mm SVL. Dorsal scalation heterogeneous, minute granular scales with enlarged, regularly-arranged, rounded tubercles in 8 to 9 longitudinal rows at midbody extending posteriorly from the nape or occiput. Limbs and digits long, with enlarged basal lamellae under and proximal to penultimate interphalangeal joint (4 under digit IV). Original tail slightly longer than SVL; dorsum of tail tuberculate, four rows of pointed, keeled tubercles proximally, becoming more rounded and reducing to only two rows distally; median subcaudal scales with alternating pattern of single enlarged scales and pairs of somewhat smaller scales. Male precloacal pores in a single continuous row of 8–13. Dorsal pattern of dark and light spots and yellowish lines on a gray-brown background; tail distinctly banded. Ventral coloration whitish with dark markings on throat and trunk and a yellow to orange tail venter.

Comparisons with Congeners. Ancylodactylus kituiensis sp. nov. may be distinguished from A. spinicollis and A. petrodroma in lacking an enlarged preaxial metatarsal scale and from these two species plus A. alantika in having a series of flattened, rectangular lamellae subtending the second and third phalanges of the pedal digits, rather than single enlarged, rounded scale (plaque of Perret 1986) at the penultimate joint of each digit. It is distinguished from A. africanus , A. elgonensis , A. barbouri , A. koehleri , A. dilepis , A. gigas , A. kenyaensis sp. nov., A. mathewsensis sp. nov., A. laikipiensis sp. nov., and A. chyuluensis sp. nov by bearing two or more rows of tubercles on the post-pygal (autotomic) portion of the tail dorsum. It has more longitudinal rows of dorsal trunk tubercles (8–9) than A. quattuorseriatus , A. dilepis , A. mathewsensis sp. nov., A. laikipiensis sp. nov., A. spawlsi , sp. nov., and A. chyuluensis sp. nov. (maximum four rows), and fewer than A. elgonensis (10–14) and A. kenyaensis sp. nov. (12–16). It possesses a lower number of precloacal pores (8–13) than A. barbouri (14) and A. gigas (15–16) and a higher number than A. mathewsensis sp. nov., A. laikipiensis sp. nov. and A. spawlsi , sp. nov. (6–7), It may also be distinguished in having an enlarged median series of subcaudals consisting of alternating single and paired scales from A. africanus , A. dilepis , A. gigas , A. alantika , A. mathewsensis sp. nov., A. laikipiensis sp. nov., A. spawlsi , sp. nov., and A. chyuluensis sp. nov. (all with a single median row of enlarged subcaudals) and from A. spinicollis , A. petrodroma , and A. occidentalis (irregular subcaudals). In having yellow on parts of the venter it differs from A. barbouri , A. uzungwae , A. quattuorseriatus , and A. gigas and from most other congeners it differs in having the trunk from the axillae to cloaca greyish or whitish, with only a yellowish tail, chest and neck. This difference applies to A. africanus ( Fig. 6 ), in which all but the throat is yellow, and with which A. kituiensis has been confused (see Spawls et al. 2018). At a maximum of 50 mm SVL A. kituiensis sp. nov. is smaller than A. kenyaensis sp. nov. (to 65 mm SVL) and A. elgonensis (to 61 mm SVL), but larger than A. barbouri (42 mm SVL), A. uzungwae (40 mm SVL), A. quattuorseriatus (41 mm SVL), A. dickersonae (41 mm SVL), A. dilepis (32 mm SVL), A. mathewsensis sp. nov. (40 mm SVL), A. laikipiensis sp. nov. (35 mm SVL), A. spawlsi , sp. nov. (30 mm SVL), and A. chyuluensis sp. nov. (28 mm SVL). Ancylodactylus kituiensis sp. nov. also has a single, conspicuous white or yellow tubercle on each side of the neck. This is prominent in some West African congeners, like A. spinicollis and A. alantika but, is less conspicuous in other East African taxa. In addition, the tail of Ancylodactylus kituiensis is banded, as in Hemidactylus mabouia (Moreau de Jonnès) and H. platycephalus Peters and the dorsum of both the trunk and tail lacks the chevron or fleur-de-lis type markings seen in other East African species of Ancylodactylus .

Description of holotype. Specimen generally in good condition. Body somewhat dorsoventrally flattened ( Figs. 4 , 5 ). Measurements: SVL = 51.7; TAL = 57.0; HL = 15.3; HW = 10.9; OD = 3.0; SE = 6.1. Head elongate (HL/SVL = 0.29), wide (HW/HL = 0.71), somewhat depressed, and distinct from the neck, loreal region flattened, canthus rostralis prominent. Scales on snout and loreal region domed to conical, much larger than scales of interorbital region and crown. Eyes small (OD/HL = 0.19), ear opening slit-like; two larger internasals separated in the midline by one small granular scale. 6 infralabials and 7 supralabials. Mental scale triangular, 3 postmentals, the outer pair larger than the central scale and in contact with the first infralabials and mental; 5 post-post mentals. A single prominent tubercle on lateral surface of neck anterior to each forelimb insertion.

Dorsal pholidosis heterogeneous; minute juxtaposed granules interspersed with enlarged tubercles, several times size of adjacent granular scales, arranged in about nine irregular longitudinal rows at midbody ( Fig. 4B ). Tubercles broad rounded, conical to weakly keeled; those on nape and shoulders smaller than on more posterior portions of trunk. Scattered tubercles on occipital and temporal regions smaller than those on body. Ventral scales larger than dorsal, smooth, imbricate, slightly larger in precloacal and femoral regions than on chest and belly; approximately 22 at midbody. Fore-and hind limbs relatively long, slender, covered by granular to slightly enlarged sub-imbricating scales, the latter chiefly on the preaxial surfaces. All digits moderately long and slender, strongly clawed; penultimate phalanx of all digits curved, arising angularly from distal portion of the distinctly wider basal toe pad; three wide basal lamellae, the distalmost much larger than the more proximal, and 13 narrow distal lamellae under digit IV of pes ( Fig. 4C ). Enlarged basal lamellae on digits of pes: I:1, II:3, III:4, IV:3, V:2.

Precloacal pores in a single continuous row of 12. Hemipenial bulge prominent ( Fig. 4E ), a single prominent, postcloacal spur on each side of the vent. Tail slightly depressed, slightly longer than SVL (TAL 110% SVL), tail dorsum covered in small, mostly uniform juxtaposed hexagonal to oval scales ( Fig. 4D ); distinctly segmented, especially proximally, each segment bearing near its distal margin a transverse row large, rounded tubercles. First segment posterior to hemipenial bulge with four tubercles, each drawn out into a point posteriorly and with a longitudinal midline keel along its posterior half ( Fig. 4D ). More distal tail segments with tubercles lacking distinct points and keels. From fourth segment distally only two tubercles per segment, these becoming irregular and disappearing in the distal third of the tail. Midventral subcaudal scales with a single enlarged scale alternating with a pair of smaller scales ( Fig. 4E ).

Coloration (in preservative). Dorsum light grayish-brown with dark blotches and a series of marks along the back ( Fig. 4A ). Dorsolateral tubercles brownish, darker than base color. Crown of head brown with some dark marks; infralabials and supralabials pale with dark stippling. Limbs brown with slightly darker transverse mottling or bands, digits also with dark banding. Tail grayish-brown with dark bands visible distally. Body venter creamwhite. Throat with a faded pattern of thin, mostly longitudinal, dark markings. Tail venter light cream.

Coloration (in life). Based on photographed paratypes (see Fig. 5 ). In life, during the day, the dorsal color is mainly shades of light gray-brown, with approximately six pairs of darker brown paravertebral markings from nape to tail base, these separated by thin, golden to pale lichenous, complete or broken transverse bands which extend on to the flanks ( Fig. 5C ). Either the paravertebral markings or the transverse bars may dominate and a vertebral stripe is sometimes present. In some individuals the two pairs of dark spots on the neck and shoulder are particularly dark and or prominent. The head is light grayish-brown with some small, dark scattered markings. Labial scales with alternating light (yellowish) and dark brown markings. Margins of orbits yellow. Prominent neck tubercle and surrounding granules whitish to very pale yellow ( Fig. 5A–C ). Limbs mottled to banded with alternating mustard colored and chestnut markings; digits with well-demarcated dark brown bands that are shorter than the intervening pale beige to brown interspaces. The tail is golden to mustard-colored with 6–7 reddish-brown to chestnut bands ( Figs. 5A, 5C ). Dorsal color may be affected by the substrate on which the gecko is resting and/or external stimuli, such as prevailing weather conditions. Ventral body color off-white with scattered pale yellowish scales. Neck and forebody to forelimb insertions up to shoulders and on to ventral surfaces of limbs a bright yellow or orange ( Figs. 5B, 5D ). Chin and throat bright white with thin brownish chevron marks which continue on to the yellow neck ( Fig. 5D ). Tail venter pale yellow, bolder on ventrolateral surfaces. Postcloacal tubercle yellow. In contrast, in Ancylodactylus africanus except for the throat, which may be mottled whitish, the underside, including the chest, belly, limbs and tail, is yellowish. ( Fig 5 ).

Variation. Mensural data for the type series is given in Table 2 . All paratypes generally resemble the holotype (see above and Fig. 5 for color variation). Comparative data for Ancylodactylus africanus is given in Table 3 . Males have a continuous series of 8 to 13 precloacal pores ( Fig 3 , Table 4 ).

Etymology. Named for Kitui County, the more inclusive locality within which the dryland rocky hills and outcrops occupied by this species occur.

Natural History. This is a diurnal arboreal gecko found on rock outcrops with crevices, as well as on tree trunks. It is alert and quick to retreat into rock crevices when disturbed. At Mutha Hill the species was found to be microsympatric with the Tropical House Gecko, Hemidactylus mabouia (Moreau de Jonnès) and at Mutomo Hill, with Hemidactylus platycephalus Peters. At Nzambani Rock and in Mutomo Hill rock outcrops they were found to occur in colonies of about ten individuals in the same rock caves. These rock outcrops also harbor the Northern Rainbow Skink or Five-lined Skink Trachylepis quinquetaeniata (Lichtenstein) , the Kenya Red-headed Rock Agama Agama lionotus Boulenger , and the Pancake Tortoise Malacochersus tornieri (Siebenrock) .

Habitat and Distribution. This is a dryland hilltop, montane forest, and rock outcrop species. It is known from Mutha Hill, Mutomo Hill, Endau Hill, and Nzambani Rock from elevations of about 800 m to about 1400 m. It is likely present on other dryland rocky hills and rock outcrops (kopjes) in the region with similar characteristics, such as Kanziku, Mutitu, Mbitini, and Nuu. Further north this species, or perhaps a different congener, could be present in the Mumoni Hills in Mwingi.

Figures

FIGURE 3. Ancylodactylus kenyaensis sp. nov., in life. A) Holotype (NMK-220L/2), adult male, dorsal view, note trombiculid mite infestation. B) Holotype venter showing lack of bright pigmentation. C) Adult female paratype (NMK-220L/1); D) Tree trunk microhabitat of A. kenyaensis in Chuka Forest, Meru South, Thiraka-Nithi County, Kenya.

FIGURE 4. Holotype of Ancylodactylus kituiensis sp. nov. (NMK-L2702/2). A) Dorsal view of the preserved specimen. Scale bar = 10 mm. B) Dorsal view of anterior trunk showing prominent rows of tubercles. C) Ventral view of left hind foot. D) Tail dorsum showing the enlarged tubercles. E) Subcaudal view showing irregular alternation of larger and paired smaller median scales at mid-venter of tail.

FIGURE 5. Ancylodactylus kituiensis sp. nov. A–B) Live adult male paratype NMK-L3559/1 inside rock cave at Nzambani Rock. C–D) Freshly dead male paratype NMK-L3775/1 from Mutomo Hill rock outcrops showing dorsal and ventral coloration, respectively. Photos A–B © P.K. Malonza, photos C–D © Domnick Victor Wasonga.

FIGURE 6A. Ancylodactylus africanus in life. A–B) Adult female, dorsum (NMK-L3622/3) and venter (NMK-L218L), respectively; Shimba Hills National Reserve. C) Male (NMK-L3924/L) on rock cave ceiling, Ngulia Hills. D) Ventral surface of specimen in image C. Photos: A–D © P.K. Malonza.