Two additional treefrogs of the Boophis ulftunni species group (Anura: Mantellidae) discovered in rainforests of northern and south-eastern Madagascar
Author
Köhler, Jörn
Author
Glaw, Frank
Author
Vences, Miguel
text
Zootaxa
2008
1814
37
48
journal article
10.5281/zenodo.182843
541e9a28-a278-46e7-8eaa-2dfce818cce3
1175-5326
182843
Boophis lilianae
sp. n.
Holotype
.
ZSM
201/2006 (field number
ZCMV
2864), adult male, from km 6 on road Ifanadiana–Tolongoina,
21°21'21'' S
,
47°36'47'' E
,
468 m
above sea level, Fianarantsoa Province, Southern Central East of
Madagascar
, collected on
22 February 2006
by L. Raharivololoniaina.
Paratype
.
ZSM
202/2006 (field number
ZCMV
2865), adult female, same data as
holotype
.
Remark.
This species was referred to as
Boophis
sp.
aff.
rappiodes
"South" by Glaw & Vences (2007: pages 174-175).
Diagnosis.
A species of the
B. ulftunni
species group (sensu
Wollenberg
et al.
2008
).
Boophis lilianae
is so far the smallest known species in the genus. It is distinguished from other species groups of
Boophis
containing green species as follows. From members of the
B. albilabris
and
B. microtympanum
species groups, the new species differs by green dorsal colouration with translucent shade in life (versus opaque green) and much smaller size. It mainly differs from all species in the
B. rappiodes
and
B. mandraka
groups by a pigmented ventral side (versus inner organs visible through transparent ventral skin) and smaller size.
Boophis lilianae
differs from all species of the
B. albipunctatus
and
B. luteus
groups by smaller size and lack of lateral dermal fringes along lower arm and tarsus. Furthermore,
B. lilianae
strongly differs from all the species contained in the mentioned groups by molecular characters. From the other two species in the
B. ulftunni
group,
B. lilianae
mainly differs as follows: From
B. ulftunni
by smaller size (SVL 18.3 versus
21-24 mm
in males, 20 versus
32–38 mm
in females), iris colouration (inner iris ring silvery grey versus purple) and mucronate snout shape in males. From
B. baetkei
by smaller adult male size (30.8 versus
18.3 mm
SVL), mucronate male snout shape in dorsal view (versus rounded) and a relatively smaller tympanum.
Boophis lilianae
furthermore differs from
B. baetkei
and
B. ulftunni
by the lack of prominent vomerine odontophores.
Description of the
holotype
.
Adult male, SVL
18.3 mm
. Body slender; head as wide as long, wider than body; snout mucronate in dorsal view, obtuse in lateral view; nostrils directed laterally, distinctly protruding, as close to tip of snout as to eye; canthus rostralis rounded, loreal region slightly concave; tympanum distinct, rounded, TD 30% of ED; supratympanic fold weak; tongue narrowly cordiform, posteriorly distinctly bifurcated and half free; vomerine odontophores not evident; choanae small, rounded. Arms slender, subarticular tubercles small, single, round, weakly developed; metacarpal tubercles not recognizable; fingers with basal webbing and lateral dermal fringes; webbing formula 1(1),
2i
(2), 2e(1),
3i
(2), 3e(1.5), 4(1); relative length of fingers 1<2<4<3; finger discs moderately enlarged; distinct, medium-sized nuptial pad on inner side of first finger, unpigmented. Hindlimbs slender; tibiotarsal articulation reaching snout tip when hindlimb is adpressed along body; lateral metatarsalia separated by webbing; inner metatarsal tubercle distinct, elongated; no outer metatarsal tubercle; webbing between toes well-developed, lateral dermal fringes present; webbing formula 1(1),
2i
(1), 2e(0.25),
3i
(2), 3e(0),
4i
(0.75), 4e(0.75), 5(0.5); relative length of toes 1<2<5=3<4; toe discs moderately enlarged. Skin smooth on dorsal surface with widely scattered minute tubercles, smooth on throat and chest, coarsely granular on belly, glandular around cloacal opening; no distinct enlarged tubercles in the cloacal region.
Measurements (in mm): SVL 18.3, HW 6.5, HL 6.5, ED 2.7,
END
1.0, NSD 1.0, NND 1.9, TD 0.8, TL 9.4, HAL 5.4, FOL 7.0, FOTL 12.2.
FIGURE 3.
Male holotype of
Boophis lilianae
sp. n.
(ZSM 201/2006) in life.
A
. Dorsolateral view,
B
. Ventral view. SVL 18.3 mm.
After nineteen months in preservative, ground colour of flanks, dorsal and ventral surfaces creamy yellow. A pink canthal stripe running from tip of snout to upper eyelid. Nostril encircled by thin brown line. Upper eyelid covered by brown blotch, bordered by pink spot posteriorly. Triangular brown fleck between eyes, its tip directed posteriorly. Thin pink supratympanal line continuing as thin dorsolateral line, fading at level of urostyle. Two fine longitudinal parallel stripes on mid-dorsum formed by rows of pink spots, extending from behind scapular region to level of sacral vertebra. Few minute pink spots irregularly scattered on dorsum. Small pink fleck on knee.
In life, ground colour of upper surface of head, dorsum and flanks translucent yellowish green, slightly transparent in groin. A reddish canthal stripe running from tip of snout to upper eyelid. Thin reddish supratympanic line continuing as fine red dorsolateral line and fading at level of urostyle. Upper eyelid covered by reddish brown blotch. Weak brownish triangular fleck between eyes, its tip directed posteriorly. Two fine longitudinal parallel stripes on mid-dorsum formed by rows of reddish to pink spots, extending from behind scapular region to level of urostyle. Between these stripes, some irregular pink marbling on mid-dorsum. Few minute irregularly scattered reddish brown spots on dorsum. Irregular reddish brown spots on heel and knee. Dorsal surfaces of fingers, toes and terminal discs yellowish green. Ventral surfaces of limbs, chest and posterior half of throat translucent turquoise green, anterior half of throat translucent yellowish green. Belly white with a turquoise shade. Bones green. Inner iris silvery grey, with a fine brownish circular line. Outer iris golden yellowish, with a black triangular fleck median above and below pupil, respectively. Posterior iris periphery black, followed by light blue (
Fig. 3
).
FIGURE 4. A
. Female paratype of
Boophis lilianae
sp. n.
(ZSM 202/2006) in life, dorsolateral view. Note eggs visible through transparent skin. SVL 20.0 mm.
B
. Male and female of
Boophis lilianae
sp. n.
in amplexus, showing the minimal sexual dimorphism in body size.
Variation.
Measurements (in mm) of the female
paratype
are as follows: SVL 20.0, HW 7.2, HL 7.1, ED 2.7,
END
1.5, NSD 1.3, NND 1.9, TD 1.0, TL 11.0, HAL 5.8, FOL 8.3, FOTL 13.6. The snout is rather truncate in dorsal view in the
paratype
, compared to the distinctly mucronate shape in the
holotype
. In preservative, the
paratype
exhibits more extensive pink colour on dorsum, formed by several irregular blotches and flecks on mid-dorsum. The pink dorsolateral lines are partly interrupted, generally wider and more irregular in outline. The brown flecks on upper eyelids contain a layer of pink colour. Two distinctly separated pink middorsal spots are present posteriorly to the triangular brown fleck between eyes. In life, the red dorsolateral stripes are bordered by bold silvery white blotches. Minute white spots are scattered on dorsal surfaces of limbs. The skin in groin and posterior dorsum is almost completely transparent (
Fig. 4A
). Tentatively judging from the two available specimens, a difference of only 8.5% in the SVL between the adult male and adult female, sexual dimorphism in body size is less pronounced than usually observed in species of green
Boophis
(see
Fig. 4
B).
Molecular differentiation.
A 16S rRNA sequence (462 bp) of the
holotype
of
B. lilianae
has been deposited in Genbank (accession number
EU314953
). This sequence had an uncorrected sequence divergence of 8.7% (40 substitutions) as compared to the
holotype
of
B. baetkei
, and of 10.0% (46 substitutions) to
B. ulftunni
.
FIGURE 5.
Schematic map of Madagascar showing the known distribution of species in the
Boophis ulftunni
group.
Distribution and natural history.
So far only collected from the
type
locality. The two
type
specimens were collected at night in amplexus. They were sitting on low vegetation in a swampy area formed by a slowly moving stream that flooded large parts of a small patch of dense palm forest next to highly degraded rainforest. The female contains yellowish eggs (each approximately
1.6 mm
in diameter) in its oviducts as visible through the transparent skin on flanks, indicating that reproduction was taking place at the time of collecting (during the rainy season).
Boophis lilianae
occurs in sympatry with
B. madagascariensis
,
B. opisthodon
, and
B. pyrrhus
. Despite intensive searches at the
type
locality, on the same day the amplecting specimens were collected, and on at least 5 other occasions, no further specimens could be found and no calls potentially assignable to this species were heard. In 2007, we collected, at the
type
locality, tadpoles assignable to this species which will be described elsewhere. One further pair in amplexus, tentatively assignable to this species, has been observed and photographed by A. Strauß and J. Glos on
22 January 2008
at a site locally known as Imaloka in the Ranomafana National Park (
21°14’32’’ S
,
47°27’55’’ E
, approximately
900-1000 m
a.s.l.). The specimens were sitting about
1.5 m
high on leaves of a shrub above a small, rather slow moving stream with sandy substrate. According to our observations,
B. lilianae
may either be very secretive or seasonal in its calling behaviour.
Etymology.
This species is dedicated to Liliane Raharivololoniaina who collected the two
type
specimens, in recognition of her contribution to the study of Madagascan amphibians and her continuous help during our field expeditions. The terminal "e" in "Liliane" has intentionally been omitted in the species name for easier pronunciation.