Description of a new flat gecko (Squamata: Gekkonidae: Afroedura) from Mount Gorongosa, Mozambique
Author
William R. Branch
Author
Jennifer A. Guyton
Author
Andreas Schmitz
Author
Michael F. Barej
Author
Piotr Naskrecki
Author
Harith Farooq
Author
Luke Verburgt
Author
Mark-Oliver Rödel
text
Zootaxa
2017
2017-09-26
4324
1
142
160
journal article
31986
10.11646/zootaxa.4324.1.8
4de1fb75-1a31-4228-bc0c-6ad2f4b99c45
1175-5326
997117
B4Ff9A5F-94A7-4E75-9Ec8-B3C382A9128C
Afroedura gorongosa
sp. nov.
(
Figs. 4–5
)
Afroedura transvaalica
(part)
Broadley 1966
, p. 111.
Holotype
.
ZMB
83293 (GNP 484), adult male, western flank of
Mount Gorongosa
,
Gorongosa National Park
,
Sofala Province
,
Mozambique
(
1038 m
a.s.l.
, 18˚28’04.3”S, 34˚02’53.2”E), collected by M.-
O. Rödel
and
M.F. Barej
,
11 December 2015
.
Paratypes
(three specimens). ZMB 83290 (GNP 438), adult female, with incision in left thigh; PEM R22220 (GNP 439, previously ZMB 83291), adult female, with incision in left thigh;
ZMB
83292 (GNP 440; will later be deposited in the zoological collection of the
E.O.
Wilson Laboratory
in Gorongosa National Park), adult male, with everted hemipenes and incision in left thigh; collected on
22 May and 21 July 2015
by
J.A. Guyton
and
P. Naskrecki
from gallery forest near
Murombodzi Waterfall
,
Mount Gorongosa
,
Gorongosa National Park
,
Sofala Province
,
Mozambique
(
842 m
a.s.l;
18°29'0.1''S
,
34°2'34.6''E
).
Additional material
(two specimens). ZMB 83288 (GNP 433), adult male,
ZMB
83289 (GNP 434), adult female; both collected in
April 2015
by
H. Farooq
,
P. Naskrecki
and
J.A. Guyton
from the top of Bunga Inselberg, Gorongosa National Park,
Sofala Province
,
Mozambique
(approx.
200 m
a.s.l.
, 18˚35’58.1”S, 34˚20’34.8”E).
Etymology.
The specific name refers to Mount Gorongosa and Gorongosa National Park in Central
Mozambique
, to which the species is endemic. We suggest Gorongosa Flat Gecko is a suitable common name.
Afroedura
, based on
Oedura
, is feminine and the specific epithet is treated as a noun in apposition.
Diagnosis.
A member of the
A. transvaalica
-complex in possessing two pairs of enlarged scansors per digit and a strongly verticillate and flattened tail (
Jacobsen
et al.
2014
). Differs from other members of the complex by having 97–102 midbody scale rows (less than
95 in
A. bogerti-
complex, 113–120 (= 117) in
A. loveridgei
and
102–119 in
A. transvaalica
(102–118, =
109 in
South Africa—Jacobsen
et al.
2014; 108–119, =
114 in
Zimbabwe
adjacent to Mount Gorongosa); by the rostral bordering the nostril (nostril excluded from rostral in
A. loveridgei
); by the anterior nasals being separated by 1–3 granules (always in broad contact in
A. loveridgei
; usually in broad contact in
A. transvaalica
-
<3% in
South Africa
populations, 18% separated by a single granule in
Zimbabwe
adjacent to Mount Gorongosa); in having 19–22 scales between the anterior borders of the eyes (
15–19 in
A. loveridgei
;
17–20 in
South African
A. transvaalica
,
and
15–19 in
Zimbabwe
populations adjacent to
Mozambique
); and in having a higher average number of precloacal pores in males (8–13, = 10; 6–10, =
8 in
A. transvaalica
; 8–10, =
9 in
A. loveridgei
).
Holotype
description.
Morphology
. Adult male; SVL
50.8 mm
; tail
52.2 mm
(partly regenerated), with a small incision in the left thigh for the removal of muscle tissue. Head and body dorsoventrally depressed; HL
12.3 mm
, HW 9.0 mm, broadest at mid-eye and 1.37x longer than wide. Eye large (
3.7 mm
wide), pupil vertical with indented margins; circumorbital scales small and granular, becoming elongate, almost ciliate, at upper posterior margin. Snout rounded,
4.9 mm
long, longer than distance between eye and ear openings (
3.6 mm
). Scales on top of snout granular, rounded and convex, the largest being 2/3rds the width of the scales on the back, which are granular and juxtaposed, with no intervening minute granules. Scales on snout almost twice as large as those on crown and throat. Scales on belly flattened, imbricate, more-or-less ovate at mid-ventrum, and twice the size of lateral granules and 1.5x those along backbone. Ear opening deep, oblique and roughly oval, only half as high as wide.
Limbs well developed, hindlimbs slightly longer than forelimbs, both without obvious mite pockets at posterior margin of limb insertions. All digits with a large pair of distal scansors, separated by a large, curved claw, and followed after a large gap (twice length of terminal scansor) by a smaller pair of scansors; infero-median row of digital scales enlarged transversely, particularly towards the scansors, where the terminal scale adjoining the first pair of scansors may be medially constricted, swollen and scansor-like; 12 scale rows under 4th toe.
Nostril pierced between rostral, 1
st supralabial
and three nasal scales; the supranasal being much larger than the subequal postnasals and separated by a granule bordering the rostral, followed behind by two smaller granules. Rostral roughly rectangular but with its upper edges elongated due to extensions into the nostril. Nine supralabials on each side, the labial margin flexing dorsad at the rictus, with 1–2 minute scales proximal to the flexure. Nine infralabials on either side, with a small scale proximad to the flexure. At the lip, mental slightly narrower than adjacent infralabial, only 2/3rds the width of rostral, and in contact with two distinctly elongate postmental scales.
Approximately 20 scales across crown at level of front of eye; 13 scales between nostril and front of eye; 23 scales from front of ear to back of eye; 99 scales around midbody.
FIGURE 4.
Afroedura gorongosa
sp. nov.
a) male holotype (ZMB 83293, Mount Gorongosa, Mozambique; photo: M.-O. Rödel); b) female paratype (ZMB 83292, Mount Gorongosa, Mozambique; photo: P. Naskrecki) showing dorsal pattern and regenerated tail; c)
Afroedura gorongosa
(ZMB 83289, Bunga Inselberg, Gorongosa National Park, Mozambique; photo: C. Dorse).
FIGURE 5.
Afroedura gorongosa
sp. nov.
female paratype (PEM R22229, previously ZMB 83291, Mount Gorongosa, Mozambique; photos: P. Naskrecki); a) general habitus and dorsal coloration; b) close up of nasal region showing diagnostic features of: presence of internasal granules, and posterior projection of rostral to border the nostril; c) close up of lower side of left forelimb; and d) close up of right hind foot showing two paired scansors.
A roughly V-shaped row of 13 precloacal pores occurs eight scale rows anterior to the cloacal lip, with these scales more imbricate and triangular adjacent to the precloacal pores. Original portion of tail slightly dorsoventrally flattened and indistinctly verticillate, without obvious lateral constrictions; each verticil comprising 6–7 imbricate rows of scales dorsally and 5 imbricate scale rows ventrally, and with ventral scales approximately twice the size of those on dorsal surface. Hemipenal pouches well-developed, with an angular, ventro-lateral series of 3 enlarged tubercular scales on each side (largest nearest cloaca), and with two openings of the cloacal sacs on the posterior lip of the cloaca.
Colour in life
(from photographs,
Fig. 4a
and unpublished). Dark black-brown above with a series of five white dorsal spots (4–5 scales across) between the fore- and hind-limb insertions, that are surrounded by a chocolate brown zone that encompasses a series of 2–4 laterally arranged smaller pale spots (2–3 scales wide), and posteriorly by a diffuse pale region that forms an irregular band across the mid dorsum. Top of head, flanks and upper surfaces of limbs with small, scattered pale spots. Head with a dark brown band across the posterior edge of crown encompassing a small central pale spot; a vague, thin pale canthal stripe, extends on both sides from the nasal region to front of eye; upper and lower labials grey-brown with diffuse yellowish bars; iris reddish brown with a heavy dark brown reticulation, and pupil with crenulated edge. Original segment of tail mottled in dark brown and pale blotches; regenerated tail grey with vague darker blotches. Ventrum mottled grey-cream.
Colour in preservative.
Dark black-brown above with irregular markings on back, comprising four equally spaced dark bars, each with a central white spot 4–5 scales wide, and an irregular, paler brown bar behind; top and sides of head, flanks and upper surfaces of limbs with small, irregular pale spots; ventral surface of throat, neck, belly, limbs and tail uniform dark grey. Side of head and labials dark brown, with a few scattered pale spots on upper labials, and vague pale edges to lower labials.
Variation in
paratypes
and additional material
(
Figs. 4b, 4c
,
5
;
Tables 3–4
).
Morphology.
SVL from
54.6 mm
(
ZMB
83289) to
61.2 mm
(
PEM
22220); head length 1.24–1.38 times head width (max. in
paratypes
1.38); snout only 1.5 times diameter of eye in one specimen. The supranasals always separated by granules, usually with a single large granule in contact with the rostral between the supranasals, followed by 2–3 smaller granules in lateral contact; the first upper labial and rostral always enters the nostril, and the width of the rostral at the lip margin is always wider than that of the mental (except in
ZMB
83290 were they are subequal); always two postmental scales; supralabials more than in
holotype
(10–11), infralabials (9–10); scales between anterior edge of eye 19–21; scales between nostril and anterior edge of orbit 12–13; scales between anterior edge of ear and rear margin of orbit 21–24; scales around mid-body 97–101; subdigital lamella beneath 4th toe 10–11; dorsal scales per tail verticel 7–8; ventral scales per tail verticel 5.
In one female (
ZMB
83290) the terminal, medially-constricted subdigital lamella of the 3rd toe of left foot is swollen and scansor-like, bearing small setae. Precloacal pores
8–13 in
males, females without dimples in precloacal scales (as in
A. transvaalica
,
but unlike
A. loveridgei
where five females had 5–9 dimpled precloacal scales, that lacked secretory activity, and only one had none).
Colour in life
(based on female
paratype
PEM
R22229). Boldly patterned, with six dorsal dark transverse bands, posteriorly edged with cream, the first on the neck, the second and sixth at the fore- and hindlimb insertions, respectively, and with three thin bands equally spaced between them on the body; background colour of body, head and upper surfaces of limbs flecked on light brown and cream with occasional pale spots 2–4 scales wide; a dark canthal stripe runs through the rostral to the front of the eye, with a paler zone above; the scales of the anteriordorsal region of the orbital rim are bright yellow, with a faint yellowish infusion of the crown scales between the eyes; the original tail is boldly barred dorsally with seven, subequally-spaced, dark brown-black bars with a yellow posterior edge; belly uniform cream with scattered yellowish scales, greyer on ventral surfaces of limbs and tail.
Colour in preservative.
Similar to
holotype
, but dorsum pale brown to grey; larger dorsal markings usually reticulated, occasionally forming irregular transverse bands (6–7 from occiput to between hindlimbs); smaller dorsal markings vary from vague to distinct. A few specimens have irregular pale blotches along the posterior edges of the darker dorsal patches/bands, and also scattered on the dorsal surfaces of the limbs and back. Dorsal surface of regenerated tails usually with irregular pale and dark blotches that may form wavy bands, and which become flecks or grey blotches below.
Size.
Largest male (ZMB 83288)—SVL
56.5 mm
, tail (partially regenerated)
55.7 mm
; largest female (PEM R22220)—SVL
61.2 mm
, tail (original) 64.0 mm. It is thus intermediate in size between
A. transvaalica
(malemax. SVL
72 mm
, female—max. SVL
64 mm
) and
A. loveridgei
(male—max. SVL
59 mm
, female—max. SVL
58 mm
). Only one of six specimens had an original tail (105% SVL).
Hemipenis
(based on ZMB 83292). Approximately
5 mm
long, with a simple, smooth, possibly longitudinally flounced pedicel; capped with two large cups covered with fine calyculate ornamentation; sulcus simple and draining into the conjoined base of the distal cups.
Distribution.
Known from only three localities in the Mount Gorongosa region (
Fig. 2
). The
holotype
and
paratypes
, plus various non-collected individuals, have been found on the western flanks of Mount Gorongosa between about 900 and
1100 m
a.s.l. (
Figs. 6a–c
). Access to further potential areas on the mountain, i.e. rock faces at the eastern slopes, was not possible due to security concerns. The additional material and various non-collected specimens have been observed at a lower altitude on the Bunga Inselberg (about
212 m
a.s.l.) in the north-western corner of the National Park, approximately
40 km
from the
type
locality (
Fig. 6d
). No tissue samples from the Bunga individuals were available, and the assignment of these individuals to the new species was thus based on morphological similarity.
Natural history.
The Gorongosa National Park is situated in Central
Mozambique
approx.
100 km
south-west of the
Zambezi River
, and is in the southern part of the great African Rift Valley. Mount Gorongosa is an isolated granite mountain massif rising to
1863 m
a.s.l., north-west of the National Park’s plains. At its highest elevations the massif’s plateau is covered with montane grasslands and forest patches dominated by cypresses (
Widdringtonia nodiflora
); the upper slopes of the mountain (
900–1600 m
) support a belt of moist evergreen forest. The
type
series was collected in an area between 900 and
1100 m
on the western flanks of the mountain (
Figs. 6a–c
,
7
). The
paratypes
were collected in a small alcove beneath a boulder pile in the closed-canopy riverine forest beside the Murombodzi Waterfall, and thus in comparatively cool and moist microclimates (
Figs. 6c
,
7
). Some rocks with lizards present were located within the splash zone of the waterfall. Other specimens were observed but not collected at this site. The
holotype
was collected from a deep narrow crack in a large granite rock (i.e.
8 m
³) in highly degraded grassland below the edge of the rainforest and almost fully exposed to the sun (
Fig. 6b
). It was the only specimen seen at that site. At both sites the new species lived in syntopy with the cordylid
Smaug mossambicus
(FitzSimons, 1958)
.
The additional non-type material comes from the Bunga Inselberg (
Fig. 6d
), a partly eroded inselberg composed mostly of trachyte in the north-western corner of the national park, covered and surrounded by dense Miombo woodland at a relatively low altitude (approx.
212 m
a.s.l.). Here the geckos were observed during the day and at night in several places in deep cracks between very large boulders. No geckos were observed outside of these cracks. Syntopic lizards were
Smaug mossambicus
,
the skink
Trachylepis margaritifera
(Peters, 1854)
and the gecko
Hemidactylus platycephalus
Peters, 1854
. Further sympatric, but not syntopic geckos were:
Lygodactylus
cf.
capensis
(Smith, 1849)
,
Pachydactylus punctatus
Peters, 1854
and
Chondrodactylus turneri
(Gray, 1864)
.
FIGURE 6.
Habitats of
Afroedura gorongosa
sp. nov.
on Mount Gorongosa (a–c); a) edge of rainforest on Mount Gorongosa, the holotype was collected in a rock-crack of an isolated boulder in an open area close to the rainforest at 1038 m a.s.l. (b) and in rocky areas of the Murombodzi river (c; compare Fig. 7); d) rocky habitat on the top of Bunga Inselberg, Gorongosa National Park, Mozambique (photos: M.-O. Rödel).
FIGURE 7.
Habitat of
Afroedura gorongosa
sp. nov.
paratypes around Murombodzi waterfall, Mount Gorongosa; inset figure: J.A. Guyton collecting one of the paratypes (photos: J. Poole).
TABLE 4.
Museum accession numbers and measurements (mm) for the type series and additional material (AM) of
Afroedura gorongosa
sp. nov.
Mus. No |
Status |
Sex |
SVL |
Tail |
Head length |
Head width |
Snout |
Eye |
Ear-eye |
Internostril distance |
ZMB 83293 |
Holotype |
M |
50.8 |
52.2 |
12.3 |
9.0 |
4.9 |
3.7 |
3.6 |
PEM R22220 (ZMB 83291) |
Paratype |
F |
61.2 |
64.0 |
14.8 |
11.2 |
6.1 |
3.8 |
4.4 |
2.2 |
ZMB 83290 |
Paratype |
F |
61.1 |
49.3 |
15.0 |
10.9 |
6.1 |
3.9 |
4.7 |
2.1 |
ZMB 83292 |
Paratype |
M |
56.4 |
45.6 |
13.0 |
10.3 |
5.2 |
3.5 |
4.1 |
1.9 |
ZMB 83288 |
AM |
M |
56.5 |
55.7 |
14.2 |
11.1 |
6.0 |
4.2 |
4.3 |
1.6 |
ZMB 83289 |
AM |
F |
54.6 |
na |
13.8 |
10.7 |
5.5 |
3.8 |
4.4 |
1.8 |
The new species was observed regularly between
April and December 2015
. Like
A. transvaalica
,
it is tolerant of conspecifics and frequently several specimens, and sometimes as many as over 20, were observed sheltering in deep rock crevices. One adult female (ZMB 83290) contained two eggs of approximately 11.5 x
7.5 mm
.
Conservation Status.
The population of the new gecko present on the lower slopes of Mount Gorongosa is threatened by illegal deforestation taking place within the riverine forest adjacent to Murombodzi Waterfall. Slashand-burn removal of tall, old growth trees around the rocks may cause changes to the humidity and water availability in these currently very moist, shaded microhabitats that seem to be preferred by the lizards. Reforestation efforts led by Gorongosa National Park and introduction of shade-grown coffee as an alternative to slash-and-burn agriculture still practiced around the mountain will hopefully slow or halt the loss of the native riverine and evergreen vegetation in that area. On Bunga Inselberg the population of
A. gorongosa
is currently protected within the core area of the National Park and no immediate threat to its survival exists, though deforestation for agriculture is slowly encroaching on the area. However, based on the existence of only a few known sites and small area of occupancy, i.e. the presumed restriction to a fragmented range on Mount Gorongosa and potentially some rocky areas surrounding the mountain, as well as the ongoing high rate of habitat degradation and conversion on the mountain, the species may be considered highly threatened, potentially justifying an assessment as Endangered or even Critically Endangered. Further surveys and formal IUCN Red List assessment are required to confirm this.