A new leaf tailed gecko species from northern Madagascar with a preliminary assessment of molecular and morphological variability in the Uroplatus ebenaui group
Author
Ratsoavina, Fanomezana Mihaja
Author
Louis, Edward E.
Author
Crottini, Angelica
Author
Randrianiaina, Roger-Daniel
Author
Glaw, Frank
Author
Vences, Miguel
text
Zootaxa
2011
3022
39
57
journal article
46364
10.5281/zenodo.206497
14b73464-180e-40d0-a544-0f4d2886b466
1175-5326
206497
Uroplatus finiavana
sp. nov.
Holotype
.
ZSM
328/2004 (
FGZC
625, adult male, hemipenes partly everted) collected at Montagne d'Ambre,
700–1000 m
above sea level (a. s. l.) on
19–23 February 2004
by F. Glaw, M. Puente, R.D. Randrianiaina & A. Razafimanantsoa.
Paratypes
.
ZSM
1132/2003 (FG/MV
2002-2387
, adult male);
ZSM
1133/2003 (FG/MV
2002-2388
, adult male);
ZSM
1134/2003 (FG/MV
2002-2390
, adult female); and
ZSM
1135/2003 (FG/MV 2002-3083, adult male), all collected at Montagne d'Ambre, on
17–20 February 2003
by F. Glaw, R. D. Randrianiaina & A. Razafimanantsoa.
FIGURE 7.
Haplotype network reconstruction of a 400 bp fragment of the nuclear C-mos gene for the analysed lineages of the
Uroplatus ebenaui
group. Haplotypes were inferred using the PHASE algorithm. The haplotypes of
U. finiavana
are in yellow. In green, blue and red are those of
U. phantasticus
and
U. ebenaui
,
U. malama
,
respectively. Grey is used for the candidate species
U.
sp. 1–3 from Tsaratanana.
ZSM
322/2004 (
FGZC
619, adult female),
ZSM
323/2004 (
FGZC
620, adult female),
ZSM
324/2004 (
FGZC
621, adult female),
ZSM
325/2004 (
FGZC
622, adult female),
ZSM
326/2004 (
FGZC
623, adult male),
ZSM
327/ 2004 (
FGZC
624, adult male),
ZSM
329/2004 (
FGZC
626, adult male), all collected at Montagne d'Ambre,
700– 1000 m
a. s. l. on
19–23 February 2004
by F. Glaw, M. Puente, R. D. Randrianiaina & A. Razafimanantsoa.
Diagnosis.
Uroplatus finiavana
sp. nov.
differs from all other taxa of the
U. fimbriatus
species group (
U. fimbriatus
,
U. giganteus
,
U. henkeli
,
U. sikorae
and
U. sameiti
) and
U. lineatus
by its smaller size (adult SVL
52–65 mm
versus at least
85 mm
) and lack of lateral membranous fringes on any part of the body and limbs; and from
Uroplatus alluaudi
,
U. guentheri
,
U. pietschmanni
,
and
U. malahelo
by its smaller size (adult SVL
52–65 mm
versus
69–81 mm
), laterally compressed body with a vertebral keel, and more triangular head.
The new species is most similar to the other species of the
Uroplatus ebenaui
group (
U. ebenaui
,
U. phantasticus
and
U. malama
).
Uroplatus finiavana
differs from
U. malama
by its smaller body size (SVL
52–65 mm
versus
71–77 mm
); shorter (TaL/SVL 0.42–0.65 versus 0.61–0.72) and narrower tail (TaW/SVL 0.05–0.14 versus 0.18–0.24), an unpigmented oral mucosa (versus blackish oral mucosa), and the presence of spines on the body, head, limbs and tail base (versus their absence).
Uroplatus finiavana
differs from
U. ebenaui
by its slightly larger body size (SVL
52–65 mm
, mean
58.2 mm
versus
45–63 mm
, mean
54.3 mm
), longer tail (TaL/SVL 0.42–0.65 versus 0.22–0.40), longer forelimb (ForL/SVL mean 0.42 versus 0.38), posteriorly curved interorbital ridge (versus almost straight), the median posterior extension of the ridge (1.6–3.0 mm versus 0.0–
1.1 mm
), more extended neck triangle (neck-triangle length
7.3–14.2 mm
versus
1.7–3.4 mm
), and by its non-pigmented oral mucosa (versus blackish oral mucosa).
Uroplatus finiavana
differs from
U. phantasticus
in its slightly smaller body size (SVL
52–65 mm
, mean
58.2 mm
versus
52–76 mm
, mean
60.3 mm
), shorter (TaL/SVL 0.42–0.65 versus 0.62–0.76) and narrower tail (TaW/ SVL 0.05–0.14 versus 0.16–0.20), and its unpigmented oral mucosa (versus blackish oral mucosa).
In addition,
U. finiavana
differs from all other species of the
Uroplatus ebenaui
group (see
Figures 6
and
7
) and from all other species of
Uroplatus
(
Greenbaum
et al.
2007
;
Raxworthy
et al.
2008
) by its substantial degree of genetic differentiation.
Description of the
holotype
.
Male specimen in good condition, with original tail attached to the body and partially everted hemipenes. Measurements and counts of the
holotype
: snout-vent length 59.0 mm, tail length
35.3 mm
, maximum tail width
5.7 mm
, and right forelimb length
25.5 mm
. Head triangular in dorsal view, postorbital region (measured from posterior border of eye to anterior border of ear opening) of similar length to that of the snout (from anterior eye border to snout tip); snout sloping strongly and continuously downward anteriorly; snout depressed, short (1.3 times longer than eye diameter); canthus rostralis indistinct; eyes large, bulging slightly above dorsal surface of cranium, directed laterally, pupil vertical with crenate borders; ear opening very small (horizontal diameter
0.6–0.8 mm
), its opening facing posterolaterally, but also posteroventrally (ear opening clearly visible in ventral view); nares laterally oriented; body somewhat laterally compressed, without lateral fringes; limbs well developed, without fringes, forelimb reaches beyond tip of snout and almost to the groin (forelimb length/axillagroin distance 98%), hind limb reaches beyond axilla (hind limb length/axilla-groin distance 132%); tail 60% of snout-vent length, membranous borders of the tail narrow (maximum width on each side
1.6 mm
) and completely absent from the distal tip of the tail. Nares separated from each other by eight small granular scales, from the first supralabial by one scale, and from the rostral scale by two scales; first supralabial taller than others; rostral entire, much wider than tall; mental scale very small, not differentiated from infralabial scales (total series of infralabials, left and right, plus the intervening mental scale yields a count of 35); no enlarged postmental scales or chin shields; dorsal and ventral scales of head, neck, body, limbs, and tail small, granular, juxtaposed and largely uniform in size, except for the irregular lines on the head and body which consists of series of slightly enlarged scales. Two curved lines starting at the posterolateral parts of the head converge in the neck forming a V-shaped pattern (neck triangular line). A curved, moderately distinct and posteriorly directed line is present between the eyes and connects the supraciliary spines. Several spines on the posterior parts of the head, on hind limbs and a single pointed flap on the posterior portion of each upper eyelid; upper eyelid becomes broader as it approaches the parietal region of the head.
Coloration:
All dorsal surfaces are brown in color except the tail which is light brown mottled with greybrown and with few dark spots on the neck and one larger dark spot on the middle of the back after more than 6 years in alcohol. The mottling of the body is configured as a series of fine posteriorly directed markings along the dorsum. Tail is uniformly light brown. Two whitish spots present below each eye.
Chin
and throat beige with a distinct blackish wide V-marking that merges together to form an indistinct dark longitudinal line that fades on the throat. Venter is light grey with few scattered small darker spots. Lower hind limbs and feet are slightly darker than other ventral surfaces. Postpygal portion of tail is marked with a whitish spot. Oral mucosa unpigmented.
Variation.
The dorsal ground color varies from light beige (ZSM 323/2004, 325/2004, 326/2004, 327/2004) to reddish-brown (ZSM 324/2004), to dark-brown (ZSM 322/2004) and grey (ZSM 329/2004). Dark spots are most evident in those
paratypes
with light beige ground color, whereas the other specimens are largely uniform in coloration and lack prominent dark spots.
The ventral side of all
paratypes
is similar to that of the
holotype
except for two characters. First, the V-marking on the chin of the
holotype
is absent from two of the
paratypes
(ZSM 322/2004 and ZSM 329/2004) or is indistinct (ZSM 1135/2003 and ZSM 1132/2003) and also, the scattered dark spots are absent from three
paratypes
(ZSM 324/2004, ZSM 322/2004 and ZSM 329/2004). One of the
paratypes
(ZSM 327/2004) shows distinct lateral dark line starting slightly under the axilla and continues to the groin. The presence of a white spot in the postpygal area is not constant and is only found in three of the eleven
paratypes
.
Color photographs most likely showing
Uroplatus finiavana
have appeared in several publications, including those of
Andreone (1991)
,
Glaw & Vences (1994: color photo 252)
,
Böhme & Henkel (1995: Figures 11, 12, 13, 14)
, Svatek & van
Duin (2002)
, Glaw & Vences (2007: 378) and
Schönecker (2008: 125–126)
. The same pattern as those encountered in the preserved specimens is observed in living animals. In some specimens, the markings on the head and the dorsum are underlined with darker coloration. Whitish spots below each eye are sometimes absent or are reduced to a single one.
FIGURE 8
. Comparative pictures of the body and mouth pigmentation in living and preserved specimens of the different species of the
Uroplatus ebenaui
group. (a) female of
U. ebenaui
(ZCMV13013) from Nosy Be, November 2009; (b) male of
U. malama
(ZCMV12218) from Andreoky (Andohahela area), May 2010; (c) male of
Uroplatus
sp. 2 from Tsaratanana, June 2010; (d) female of
Uroplatus
sp. 3 from Tsaratanana, June 2010; (e) female of
U. finiavana
from Montagne d’Ambre, February 2003, live and preserved mouth pictures are not from the photographed animal; (f) male of
U. phantasticus
from Ranomafana, March 2004; (g) female of
Uroplatus
sp. 1 from Tsaratanana, June 2010.
FIGURE 9.
Map of Madagascar showing the distribution of the evolutionary lineages of the
Uroplatus ebenaui
group. Only selected localities: (1) those mentioned in the text, (2) those for which molecular data are presented herein or are available from us (unpublished), and (3) Andringitra Massif which is the southernmost record of
U. phantasticus
vouchered by a DNA sequence (Raxworthy
et al.
2008). The Zahamena locality for
U. phantasticus
bears a question mark due to the high genetic differentiation of this population, which leaves its actual specific identity in need of confirmation.
Hemipenis structure.
Because the
holotype
does not have a fully extruded hemipenis, we used one of the
paratypes
ZSM 1133/2003 with fully everted hemipenis for the description (
Figure 4
). In common with the other species of the
ebenaui
group, the hemipenis bears two lobes that become more obvious towards the apical region. The calyx displays a protuberance with a honeycomb appearance within which the sulcus spermaticus is concealed. The latter has a smooth surface. One to four folds separate the protuberance from the apex, which exhibits several papillae that wrap a single structured pedunculus in each side. A more in-depth description and comparisons with other taxa will be presented elsewhere.
Etymology.
The specific name is derived from the
Malagasy
word "
finiavana
" meaning initiative. We refer to the fact that we took the initiative to name the species following years of this taxon having been recognized as likely being distinct. The name is used as a noun in apposition.
Distribution.
In several herpetological surveys carried out in 1994, 2000, 2003, 2004,
2006 and 2009
, the new species was encountered in the rainforest of Montagne d’Ambre National Park between
700–1350 m
a.s.l. and in secondary forest fragments of lower elevation close to the town of Joffreville, where both
U. finiavana
and
U. ebenaui
occur sympatrically. This protected area is completely isolated from the major rainforest blocks of northern and eastern
Madagascar
and covers a surface area of
182 km
2 (
Nicoll & Langrand 1989
;
Raxworthy & Nussbaum 1994
). D’Cruze
et al.
(2008) reported encountering this new species in the adjacent forest (Réserve Spéciale Forêt d’Ambre) that has a lower elevation range of
400–850 m
a.s.l.; but we cannot exclude the possibility that these records may partly, or entirely, refer to
U. ebenaui
.
Records of
U. ebenaui
from the neighboring rainforest blocks (Anjanaharibe-Sud, Manongarivo, Marojejy, Tsaratanana and Makira) might be referable, by DNA sequences and morphology, to other taxa.
Habitat and habits.
The
holotype
was collected in primary forest in Montagne d’Ambre National Park during a night survey. The species is nocturnal, arboreal and is remarkably common within the national park, especially around
800–900 m
a. s. l., where it is possible to encounter 10 individuals during a single night’s walk (for instance on the path “Voie des mille arbres”). Remarkably, most of the encountered specimens have lost their original tail. One individual was observed feeding on a cockroach.
Morphometric differentiation.
Relative tail length and relative tail width were recorded as ratios relative to SVL; these values were calculated separately for males and females.
Figures 5
a and 5b show that the same pattern is evident in both sexes. The new species,
U. finiavana
, shows intermediate values of tail length and tail width relative to two other described species of its clade (
U. ebenaui
and
U. phantasticus
), and the differences are statistically supported (Mann-Whitney U test, pooling males and females; P <0.01).
Figures 5
c and 5d compare neck triangle (NTL) and medial posterior projection of the interorbital ridge length (IRPL), revealing only two clusters;
U. ebenaui
differs from
U. finiavana
and
U. phantasticus
in its smaller values for these two parameters. Significant differences only exist between
U
.
ebenaui
and
U
.
finiavana
for NTL, IRPL and relative ForL (P <0.01). There is no significant differentiation among the three species in relative hindlimb length.
Molecular differentiation and phylogenetic relationships.
The phylogenetic tree inferred from the Bayesian analysis of the mitochondrial ND4 gene is shown in
Figure 6
. We emphasize that this tree should be considered as preliminary as it is based on comparatively short sequences of a single gene. Rather than a reliable phylogeny, this tree wants to depict genetic similarities and differences among the specimens studied. On this basis, the morphological differences observed between the new species and
U. ebenaui
from the
type
locality (
Nosy
Be) and
U. phantasticus
are supported by molecular data. The tree displays a subdivision of the
U. ebenaui
group into seven deeply divergent clades, with
U. malama
occupying a basal position. Besides the described species, the tree contains additional deep genealogical lineages, which we here classify as candidate species according to the scheme of Vieites
et al.
(2009). First, based on our initial assessment of identity of the nominal species, we assume that four of these are included in the phylogram:
U. ebenaui
,
U. phantasticus
,
and
U. malama
,
plus
U. finiavana
sp
.
nov
.
as described herein. Secondly,
Uroplatus
sp. 4 from Anjanaharibe-Sud is an Unconfirmed Candidate Species (UCS) due to its high genetic divergence but insufficient morphological data to assess its status.
Uroplatus
sp. 1, 2 and 3 can be considered as Confirmed Candidate Species (CCS) because of their concordant divergence in both molecular and morphological data (e.g.: tail shape) (see
Figs. 5
and
8
).
Uroplatus finiavana
is the sister species of the clade consisting of high elevation CCS
Uroplatus
sp. 3–4, and this sister relationship is strongly supported [Bayesian Posterior Probability (BPP)= 1.00]. The cluster of
U. finiavana
and
Uroplatus
sp. 3 and 4 is the sister clade of
Uroplatus
sp. 2 (strongly supported relationship: BPP= 1.00).
The analyzed samples of
U. phantasticus
do not cluster as a monophyletic group.
Uroplatus phantasticus
from Anjozorobe and Ranomafana constitutes the sister species of
U.
sp. 1, although this sister-relationship is not strongly supported, and
U. phantasticus
from Zahamena is basal to the clade composed of
U. finiavana
and
U.
sp. 2–4, but also in this case the phylogenetic relationships are not reliably resolved. The monophyly of the clade consisting of
U. finiavana
,
U.
sp. 1–4 and
U. phantasticus
from Zahamena, Anjozorobe and Ranomafana is strongly supported (BPP= 0.98). The phylogenetic tree is somewhat concordant with altitudinal range data:
U. ebenaui
from the lowland occupies a basal position, followed by the CCS of
U. ebenaui
,
both
U. phantasticus
lineages and
U. finiavana
from mid-elevations, and by the UCS
U.
sp. 4 and the CCS
U.
sp. 3 from the high mountains in a deeply nested position.
Among the analyzed taxa, exceptionally large genetic distances (uncorrected pairwise distances shown in table 2) in the ND4 gene are evident. The highest observed value is 37.5% and is observed between
U. ebenaui
from
Nosy
Be and
U. phantasticus
from Ranomafana (individual URANO4.29), whereas the smallest value among major clades is found between the candidate species
U.
sp. 3 and
U.
sp. 4.
Uroplatus finiavana
is highly divergent from all other lineages of the
Uroplatus ebenaui
species complex. The uncorrected pairwise genetic distances of
U. finiavana
from
U.
sp. 1–4,
U. phantasticus
from Zahamena,
U. phantasticus
from Ranomafana and Anjozorobe,
U. ebenaui
and
U. malama
ranges from 20.8 to 34.5%. These large genetic distances corroborate the separation of the newly described species from all other lineages and known species included in this study. Moreover, relatively large genetic divergences are found between individuals assigned to the same species. For instance, the uncorrected genetic distance between
U. phantasticus
from Ranomafana and Anjozorobe is 6.6% and the uncorrected genetic distance between
U. ebenaui
from
Nosy
Be and Berara is 18.2%.
As our goal was not a detailed phylogenetic reconstruction but a test for concordant differentiation in two independent genetic markers for integrative taxonomic purposes (see
Padial
et al.
2010
), we analyzed the nuclear Cmos sequences separately from the mitochondrial ND4 sequences, and used a network analysis to better visualize the low degree of haplotype differentiation among the focal taxa. The haplotype network reconstruction based on the C-mos data revealed no evidence of haplotype sharing between
U. finiavana
and other species and candidate species of the
U. ebenaui
group (
Figure 7
). This congruence between mitochondrial and nuclear data supports the status of the new species as a separate evolutionary lineage and indicates the likely absence of gene flow among different lineages of the
U. ebenaui
group. Individuals from Tsaratanana assignable to
Uroplatus
sp.
1–3 in
the haplotype network (
Figure 7
) are in grey and haplotype sharing among some of these candidate species occurs. For instance,
Uroplatus
sp. 2 from Tsaratanana (ca
2000 m
a. s. l.), Marojejy and Makira’s western slope have the same haplotype as
Uroplatus
sp. 3 from the Andrevorevo part of the Tsaratanana massif (ca
1700 m
a. s. l.).