On the brink of extinction: two new species of Anomaloglossus from French Guiana and amended definitions of Anomaloglossus degranvillei and A. surinamensis (Anura: Aromobatidae)
Author
Antoine, Fouquet
Author
Vacher, Jean-Pierre
Author
Courtois, Elodie A.
Author
Villette, Benoit
Author
Reizine, Hugo
Author
Gaucher, Philippe
Author
Jairam, Rawien
Author
Ouboter, Paul
Author
Kok, Philippe J. R.
text
Zootaxa
2018
2018-02-13
4379
1
1
23
journal article
30762
10.11646/zootaxa.4379.1.1
fb2cc09e-5c36-4abb-b316-8e447e68fcba
1175-5326
1172286
31A398C2-9973-4666-B201-F37B98608CA4
Anomaloglossus dewynteri
sp. nov.
Anomaloglossus
sp.
“
Itoupé”
Vacher
et al.
2017
Holotype
.
MNHN2017.0111
(field no. AF3644/APA-973-23-2), an adult male, collected by
Antoine Fouquet
,
11 January 2016
, near base camp on
Mont Itoupé
,
French Guiana
,
3.0230 N
53.0955 W
, elevation ca. ~
600 m
(
Figure 7
).
Paratopotypes.
Three
specimens:
MNHN2017.0112
(field no. AF0574; not measured because badly preserved), an adult male, collected by
Maël Dewynter
, 0
5 April 2010
, near base camp on
Mont Itoupé
,
French Guiana
,
3.0230 N
53.0955 W
, ~
600 m
elevation
. MNHN2017.0113–4 (field no. AF3686/APA-973-23-1, AF3645/ APA-973-23-3), two adult males, collected by Antoine Fouquet, with the holotype.
Etymology.
This species is dedicated to our friend Maël Dewynter for his invaluable contribution to the herpetology of
French Guiana
.
Adult definition and diagnosis.
We assigned the new species to the genus
Anomaloglossus
based on previous studies (Fouquet
et al.
2012;
Vacher
et al.
2017
) and the presence of a median lingual process. The new species belongs to the
A. degranvillei
clade according to
Vacher
et al.
(2017)
.
(1) Medium-sized
Anomaloglossus
(average male SVL=
19.9 mm
[19.4–20.4, n=3], female unknown) (
Table 1
); (2) body robust; (3) skin tuberculate on dorsum (particularly the posterior half) and legs, with a larger tubercle on each eyelid, ventral skin smooth; (4) conspicuous dark brown to black glandulous supratympanic fold flanked anteroventrally by a discontinuous stripe (orange in life, cream in preservative) running from the ventroposterior edge of the eye and extending onto the upper arm; (5) tympanum indistinct; (6) snout short and acute in lateral view; (7) nares oriented ventrolaterally, situated near tip of snout; (8) Finger II shorter than Finger I when fingers adpressed; (9) tip of Finger IV not reaching distal subarticular tubercle on Finger III when fingers adpressed; (10) distal subarticular tubercle on Finger III and IV indistinct; (11) Finger III not distinctly swollen in males; (12) fingers with fringes particularly developed on preaxial edges of Fingers II and III; (13) toes moderately webbed, with well-developed fringes (
sensu
Grant
et al.
2006
; keel-like lateral folds
sensu
Myers & Donnelly 2008
); (14) tarsal keel well-defined, curved, slightly tuberclelike; (15) no black arm gland in males (
sensu
Grant & Castro 1998
. see also
Grant
et al.
2006
); (16) cloacal tubercles present; (17) paracloacal mark inconspicuous; (18) dorsolateral stripe absent or inconspicuous, dorsal part of flanks darker than dorsum; (19) ventrolateral stripe sometimes present as a broken, poorly defined pale brown blotch, ventral part of flanks with flecks white or bluish (in life); (20) sexual dichromatism in throat colour pattern unknown (although likely because present in other species of the clade), throat solid black in reproductive males; (21) abdomen and ventral side of legs dark grey with small ill-defined white dots; (22) iris with metallic pigmentation and pupil ring interrupted ventrally by transversal black pigmentation; (23) median lingual process longer than wide, tapered, bluntly pointed, smooth (nonpapillate), reclined in pit; (24) single note call of 0.221–
0.237 s
length and dominant frequency at 3.45–3.59 kHz (n=3) (
Table 2
;
Figure 3
).
TABLE 2.
Acoustic measurements summary statistics for the four species of the
Anomaloglossus degranvillei
clade.
Note length (s) |
Internote length (s) |
Dominant Frequency (kHz) |
A. blanci
sp. nov.
(N=6)
|
X |
0.09 |
1.41 |
4.75 |
sd |
0.01 |
0.27 |
0.37 |
A. dewynteri
sp. nov.
(N=3)
|
X |
0.23 |
0.76 |
3.52 |
sd |
0.01 |
0.15 |
0.07 |
A. degranvillei
(N=2)
|
X |
0.16 |
1.44 |
3.61 |
sd |
0.00 |
0.07 |
0.01 |
A. surinamensis
(N=20)
|
X |
0.03 |
0.57 |
4.89 |
sd |
0.00 |
0.10 |
0.20 |
Morphological comparisons with other lowland
Anomaloglossus
.
The only other species group cooccurring with the
Anomaloglossus degranvillei
species group is the
A. stepheni
species group, represented by
A
.
baeobatrachus
in
French Guiana
, which is readily distinguishable by conspicuous dorsolateral stripes, swollen third fingers in males and absence of webbing and fringes on toes.
Within the
Anomaloglossus degranvillei
group,
A. dewynteri
can be distinguished from
A. surinamensis
(
Figure 4
) by (1) a shorter snout, acute in lateral view (vs. rounded in
A. surinamensis
); (2) a larger body size in males (
X¯
=
19.9 mm
, range
19.4–20.4 mm
in
A. dewynteri
[n=3] vs.
X¯
=14.75, range 14.0–
15.3 mm
in
A. surinamensis
[n=8]); (3) more developed fringes on fingers and toes; (4) presence of a large tubercle on the top of the eyelid (inconspicuous in
A. surinamensis
); (5) belly dark grey with small white spots (vs. cream with irregular grey blotches less abundant posteriorly in
A. surinamensis
); (6) ventral surface of thigh dark grey (vs. cream with dark spots on the edges in
A. surinamensis
); (7) larger MLP (>
0.5 mm
vs <
0.5 mm
in
A. surinamensis
; (8) call characterized by much longer pulsed notes (pulsed note
X¯
=0.228, range 0.221–
0.237 s
[n=3] in
A. dewynteri
vs. tonal note
X¯
=0.032, range 0.028–
0.037 s
in
A. surinamensis
[n=20]) emitted between longer intervals (
X¯
=0.76, range 0.60–
0.88 s
in
A. dewynteri
[n=3] vs.
X¯
=0.573, range 0.372–
0.825 s
in
A. surinamensis
[n=20]) and with lower dominant frequency (
X¯
=3.52, range 3.45–3.59 kHz in
A. dewynteri
[n=4] vs.
X¯
=4.89 kHZ, range 4.55–5.35 kHz in
A. surinamensis
[n=20]).
Anomaloglossus dewynteri
can be distinguished from
A. blanci
(
Figure 2
) by (1) its larger size in males (X=
19.9 mm
, range
19.4–20.4 mm
in
A. dewynteri
[n=3] vs.
X¯
=16.9, range
15.9–18.8 mm
in
A. blanci
[n=8]); (2) belly from solid black to dark grey with abundant small conspicuous white spots (pale grey with small white illdefined spots in
A. blanci
); (3) ventral surface of thighs dark grey (yellowish in life and cream in preservative in
A. blanci
); (4) strong metacarpal ridge (inconspicuous in
A. blanci
,
Figures 2F
,
7F
); (5) call with longer notes (X=0.228, range 0.221–
0.237 s
[n=3] in
A. dewynteri
vs.
X¯
=0.094, range 0.090–
0.103 s
in
A. blanci
[n=6]) and higher dominant frequency (
X¯
=3.52, range 3.45–3.59 kHz in
A. dewynteri
[n=4] vs.
X¯
=4.75, range 4.48–5.41 kHz in
A. blanci
[n=6]).
Anomaloglossus dewynteri
can only be distinguished from the most similar
A. degranvillei
(
Figure 5
) by its call consisting of longer notes (
X¯
=0.228, range 0.221–
0.237 s
[n=3] in
A. dewynteri
[n=4] vs.
X¯
=0.158, range 0.157–
0.160 s
in
A. degranvillei
[n=2]) (
Figure 3
;
Table 2
). Molecular data provided by
Vacher
et al.
(2017)
demonstrated that these two species harbour well-differentiated mtDNA lineages (2.3% on 16S) and our phylogenetic analysis indicates that
A. dewynteri
is not the sister species of
A. degranvillei
(see below).
Anomaloglossus dewynteri
could possibly be distinguished from
A. degranvillei
by its more tuberculate skin and by its darker dorsal and lateral colouration. However, these two features should be taken with caution given the small number of specimens available and the paucity of available data from living specimens.
Description of the
holotype
(
Figure 7
).
An adult male
19.9 mm
SVL; body robust; head wider than long, HL 85% of HW; HL 32% of SVL; dorsal skin tuberculate, large tubercle on eyelids, snout large, rounded to nearly truncate in dorsal view, acute in lateral view, extending past lower jaw, SL 56% of HL. Nares located anterolaterally; canthus rostralis rounded but well defined, loreal region concave; IN 40% of HW; EN 31% of HL, 77% of ED. Tympanum indistinct; supratympanic fold present, extending from ventrodorsal corner of the eye onto the upper arm; choanae round, small, located anterolaterally.
Forelimb slender, skin tuberculate; metacarpal ridge present; HAND 25% of SVL; Finger I longer than Finger II when fingers adpressed; fingers large and flattened without webbing, lateral fringes present on preaxial edges of Fingers II and III; Finger III not distinctly swollen; tip of Finger IV not reaching distal subarticular tubercle on Finger III when fingers appressed; finger discs expanded, wider than long, about 1.5X width of digit; width of disc on Finger III
0.8 mm
. Relative lengths of adpressed fingers III> IV> I> II; palmar tubercle large, quadrangular. 1.0 mm in diameter (larger than Finger III disc), thenar tubercle small (equal to Finger III disc), elliptic, half the size of palmar tubercle, well separated from palmar tubercle. Only basal subarticular tubercles of Fingers III and IV are conspicuous; Finger I subarticular tubercle largest followed by Finger II subarticular tubercle, basal subarticular tubercle on Finger III and IV smaller, subequal. The
holotype
has a missing left hand (all the individuals collected in 2016 had some atrophied or missing fingers/toes).
Hind limb robust, skin tuberculate; TL 47% of SVL; heels not in contact when hind limbs are flexed at right angle to sagittal plane of body; FL 42% of SVL; relative length of adpressed toes IV> III> V> II> I; Toe I very short, its tip reaching the base of subarticular tubercle on Toe II when toes adpressed; discs on toes larger than width of toes; disc on Toe I only slightly larger than width of digit. Size of disc on Toe IV 1.0 mm. Feet moderately webbed, webbing present between Toes I–IV, webbing without melanophores; lateral fringes present on all toes. Toe webbing formula
I
0- -1-
II
1
½-2-
III
1
- -3
IV
3
- -2+
V
. One to three subarticular tubercles on toes as follows: one on Toes I and II, two on Toes III and V, three on Toe IV. Inner metatarsal tubercle protuberant elliptical,
0.7 mm
in length, outer metatarsal tubercle round, protuberant,
0.5 mm
in diameter. Tarsal keel well defined, tubercle-like and strongly curved at proximal end, extending distally to the fringe on preaxial edge of Toe I. Metatarsal fold strong.
Colour of
holotype
in life (
Figure 7
).
Dorsal colour dark brown, faint dorsolateral stripe, upper flanks black becoming slightly lighter ventrally with a few white-blue freckles. Supratympanic fold black bordered by a discontinuous orange postocular stripe. Upper lip brown, loreal and internarial region black. Throat solid black becoming slightly paler posteriorly, belly and ventral parts of legs dark grey with light blue freckles. Iris with reddish metallic pigmentation and pupil ring interrupted ventrally by transversal pigmentation.
Upper and posterior surfaces of arm pale orange, black anteriorly (same colour as throat). Dorsal surfaces of thigh, shank and tarsus with diffuse combination of orange, pale brown and two wide poorly defined dark brown cross bands; more cross bands on tarsus. Paracloacal marks inconspicuous. Toes and digits with small light blue dots. Palms and soles black.
Colour of
holotype
in preservative
. After one year in preservative (70% ethanol), the specimen faded and he dorsal colouration now varies from brown to grey. The bluish freckles turned cream as well as the orange and reddish marks.
Variation among
type
specimens.
Measurements (range, mean, and standard deviation) of the
type
series are provided in
Table 1
. There is only slight variation among specimens of the
type
series. However, specimens photographed in 2010 displayed a dorsal colouration going from brown with black blotches to uniform brick; flank colouration black with various pattern of brown ventroposterior marks as well as white and bluish dots (
Figure 6
).
Advertisement call (
Figure 3
).
Three specimens (one uncollected) calling from the leaf litter near a stream were recorded from a distance of about
1 m
and at temperatures ranging from 21 to 24°C. They emitted single pulsed notes (note length
X¯
=0.228, range 0.221–
0.237 s
[n=3]) at a regular pace (inter-note interval
X¯
=0.761, range 0.600–
0.883 s
). The spectral structure of the note has a developed harmonic structure and the dominant frequency is 3.52 kHz on average (range 3.45–3.59 kHz) with a slight upward modulation (ca. 0.2 kHz).
Distribution and ecology.
Anomaloglossus dewynteri
is only known from two rocky streams close to each other at
600 m
elevation, on the slope of the Itoupé massif, an isolated mountain reaching
800 m
elevation in the south-eastern part of
French Guiana
. Males call from the banks of these streams during the day and their activity seems fostered by rainfall. Many individuals were observed during the first exploration of the massif in 2010. However, only four individuals were detected in 2016 despite eight days of searching by four herpetologists, and despite any obvious perturbation of the habitat. This species co-occurs with
A. surinamensis
on the massif, but the two species were not found together along the same streams.
Anomaloglossus dewynteri
has the same reproductive mode as
A. blanci
and
A. degranvillei
, with endotrophic tadpoles carried by the male until metamorphosis. In 2010, one individual carrying six metamorphs at similar stages (Gosner stages 42–43) was observed. We cannot exclude that these metamorphs are not from two different clutches of smaller size.
Comparison with the
type
series of
Anomaloglossus degranvillei
.
Our examination of the original
type
series used by
Lescure (1975)
to describe
Anomaloglossus degranvillei
shows that it included three distinct species of the
A. degranvillei
clade occurring in
French Guiana
. Based on the original description and according to the characters observed in the
holotype
, we restrict the
type
series to the
holotype
and three of the original
paratypes
(MNHNP1973-
1656–58
) from Atachi Bakka (
3.5455 N
53.9068 W
).
Paratypes
MNHNP
1659–63
and MNHNP
1667–70
from Eaux Clément (
4.6556 N
52.2480 W
) and MNHNP
1665-66
from Cacao (
4.5610 N
52.4629 W
) correspond to
A. blanci
based on the following combination of characters: (1) body size comprised between
15.9–18.8 mm
in males; (2) belly pale grey with small white freckles; and (3) protruding snout in lateral view.
Paratype
MNHNP1973-1672 from Galbao (
3.600 N
53.2833 W
), MNHNP1664 from Saül (
3.62556 N
53.2072 W
) and MNHNP1676 from Crique Grégoire (
5.0975 N
53.0506 W
) correspond to
A. surinamensis
as inferred from the following combination of characters: (1) small body size (between 14.0–
15.3 mm
in males 16.0–
17.1 mm
in females); (2) snout short and rounded in lateral view; (3) toes moderately webbed, with fringes (4) abdomen and ventral side of legs cream with brown freckles.
Unfortunately, we could not examine LACM44211-12 from Crique Ipoussing (
4.1307 N
52.5760 W
), LG870–873 from Eaux Clément (
4.6556 N
52.2480 W
) and LACM44213–23 from Montagne Tortue (
4.300 N
52.3667 W
), but these localities lie within the range of
Anomaloglossus blanci
and, to our knowledge, no other species of the group occur there. These
paratypes
are thus excluded from the
type
series of
A. degranvillei
.