Brookesia desperata, Frank Glaw & Jörn Köhler & Ted M. Townsend & Miguel Vences, 2012

Frank Glaw, Jörn Köhler, Ted M. Townsend & Miguel Vences, 2012, Rivaling the World’s Smallest Reptiles: Discovery of Miniaturized and Microendemic New Species of Leaf Chameleons (Brookesia) from Northern Madagascar, PLoS ONE 7 (2), pp. 1-24 : 17-18

Brookesia desperata sp. n.

ZooBank LSID: urn:lsid:zoobank.org:act:C62B456C-CDA8- 4DDE-AE0A-66DF43C57F7E

Remark.—This species has been considered before as Brookesia sp. aff. karchei ‘‘Ambre’’ [ 7] and as Brookesia sp. nov. [ 41].

Holotype.— ZSM 2170/2007 ( FGZC 1250), adult male (hemipenes everted), collected at Forêt d’Ambre Special Reserve, ca. 5 km southwest of Sakaramy village, 12°28'0 0"S, 49°13'37" E, 470 m a.s.l., Antsiranana Province, northern Madagascar, on 12 March 2007 by F. Glaw, J. Köhler and A. Razafimanantsoa.

Paratypes.— ZSM 2171/2007 ( FGZC 1251), ZSM 2175/2007 ( FGZC 1258), ZSM 2176/2007 ( FGZC 1260), ZSM 2177/2007 ( FGZC 1263), ZSM 2179/2007 ( FGZC 1269), adult males (all with everted hemipenes), ZSM 2172–2174 /2007 ( FGZC 1252– 1254), ZSM 2178/2007 (FGZC 1265), adult females, all with same data as holotype; ZSM 1506/2008 ( FGZC 1880, female), and UADBA uncatalogued: FGZC 1700, FGZC 1879 (male), FGZC 3111–3112 , collected at Forêt d’Ambre Special Reserve , ca. 5 km southwest of Sakaramy village, 12°28'S, 49°13'E, 550 m a.s.l., Antsiranana Province, northern Madagascar, on 27 February 2008 by N. D’Cruze, F. Glaw and J. Köhler ; ZSM 791 /2009 ( ZCMV 13040 ), adult male (not examined morphologically), collected at Forêt d’Ambre Special Reserve , 12°28'18.0"S, 49°13'56"E, 438 m a.s.l., Antsiranana Province, northern Madagascar, on 16 November 2009 by A. Crottini, S. Hauswaldt, A. Lima, F. M. Ratsoavina and E. Rajeriarison.

Diagnosis.— A member of the Brookesia minima group based on small body size (SVL 25–30 mm) and molecular phylogenetic relationships. Brookesia desperata is distinguished from all other species in the group by the presence of three enlarged tubercles on lateral head surface (versus 0–2). In addition it differs as follows: from B. confidens by a larger adult body size (male SVL 25.0–26.7 vs. 18.3–20.1 mm), supranasal cone present (vs. absent), and hemipenis with two apical processes each with a distinct spine (vs. narrow hemipenis without apical ornaments); from B. dentata by presence of well-developed lateral spines on the tail (vs. absence); from B. exarmata by a larger adult body size (female SVL 27.3– 30.0 mm vs. 25.7–26.5 mm), and presence of well-developed lateral spines on the tail (vs. absence); from B. micra by a larger adult body size (male SVL 25.0–26.7 vs. 15.3–15.8 mm), presence of well-developed lateral spines on the tail (vs. absence), and hemipenis with two apical processes each with a distinct spine (vs. comb-like arranged papillae on apex); from B. minima by a larger adult body size (male SVL 25.0–26.7 vs. 15.0– 20.6 mm), presence of well-developed lateral spines on the tail (vs. indistinct), pelvic spine present (vs. absent or indistinct), and hemipenis with two apical processes each with a distinct spine (vs. balloon-like hemipenis without ornaments); from B. peyrierasi by a larger adult body size (male SVL 25.0–26.7 vs. 19.7–22.4 mm), presence of well-developed lateral spines on the tail (vs. indistinct), and hemipenis with two apical processes each with a distinct spine (vs. four spines on each lobe); from B. ramanantsoai by presence of welldeveloped lateral spines on the tail (vs. absence), and hemipenis with two apical processes each with a distinct spine (vs. balloon-like hemipenis without ornaments); from B. tristis by a larger adult body size (male SVL 25.0–26.7 vs. 18.0– 18.2 mm), and hemipenis with two apical processes each with a distinct spine (vs. small spinelike papillae on apex); and from B. tuberculata by a larger adult body size (male SVL 25.0–26.7 vs. 14.4–18.8 mm), presence of welldeveloped lateral spines on the tail (vs. absence), and hemipenis with two apical processes with a distinct spine (vs. a single crownlike structure on apex).

B. desperata is most similar to B. karchei in body size, number of dorsolateral pointed tubercles (12–13) and distinct lateral tubercles on tail ( Fig. 9B ). However, B. karchei differs from the new species by more pronounced supraocular and supranasal cones, more prominent and spiny posterior crest and only one enlarged tubercle at lateral side of head (three in B. desperata ).

Referencing a fragment of the 16S rRNA gene, B. desperata shows an uncorrected pairwise divergence of 6.4% to its sister species B. tristis , and divergences>6.6% to all other species of the B. minima group.

Description of holotype.— Adult male in good state of preservation ( Fig. 7 ; Supporting Information S1). Both hemipenes everted. Measurements in Table 2. Head with low lateral crest starting at median level at the posterior edge of eye; prominent orbital crests with distinctly developed supraocular cone directed anteriorly, and a crest at the posterior edge of the head, that form a weakly developed dorsal helmet; a pair of slightly curved parasagittal crests that start above the eyes and begin to converge slightly before terminating at the posterior crest; between the parasagittal crests there is a second pair of short parallel longitudinal crests; three pointed tubercles on each side of posterior helmet crest, one at termination point of lateral crest, one at termination point of parasagittal crest, and one between parasagittal and lateral crests; three pointed tubercles on lateral surface of head, one below lateral crest in temporal region, one at posterior edge of orbital crest below lateral crest, and one between lower edge of eye slightly anterior to angle of jaws; orbital crest with few enlarged conical tubercles; no supraocular cone recognizable; supranasal cone does not project beyond snout tip; head longer (6.4 mm) than wide; chin and throat without longitudinal rows of slightly enlarged tubercles. Dorsal surface of body without a vertebral ridge or keel; 13 dorsolateral pointed tubercles form a complete longitudinal line on the body; most posterior (13th) pointed dorsolateral tubercle being distinctly largest, slightly posterior to insertion point of hindlimb, projecting backwards; pointed dorsolateral tubercles almost equally spaced, 8th to 12th slightly smaller than others, pointing out almost perpendicularly from body; slightly enlarged, rounded tubercles form weakly elevated curved transversal crests on either side of the vertebral line between 1 st and 12th dorsolateral pointed tubercles; slightly enlarged tubercles on dorsal surface of tail, forming two weakly recognizable longitudinal parallel lines; barely defined dorsal pelvic shield in sacral area; lateral surface of body with densely scattered enlarged conical tubercles; venter without enlarged tubercles; scattered, conical tubercles on limbs; no pointed tubercles around cloaca; longitudinal row of distinctly enlarged tubercles lateroventrally on tail, forming a longitudinal row from tail base to three fourth of tail length; no enlarged tubercles on ventral surfaces of tail.

After almost four years in ethanol, flanks, dorsal surfaces of limbs and tail uniformly dark grey-brown; neck with distinct light grey spot; vertebral region mottled with brown and grey; throat grey, venter and ventral surfaces of tail grey-brown. Hemipenes whitish.

Variation.— For morphological measurements and proportions see Table 2 and Supporting Information S1. In life, dorsal colouration of head, dorsum and tail light grey. Lateral parts of the body beige, brown or dark brown, with few dark brown spots; limbs almost uniformly dark brown. This pattern is likely to refer to a stress colouration ( Fig. 9 ). When unstressed, most parts of the body beige, with a slightly lighter area on the head anterior to the eyes and in the vertebral region of the dorsum. In preservative, ZSM 2172/2007 is greyish with brown blotches and flecks on dorsum and flanks whereas the other paratypes are more or less uniformly dark brown. The tail base of the males is only slightly more thickened than in the females.

Genital morphology.— Everted hemipenes were available from the holotype (ZSM 2170/2007) and from four paratypes (ZSM 2171/ 2007, 2176–2177 /2007, 2179/2007). Structures were characteristic and concordant among all five specimens and are described based on the holotype. Hemipenis length is 3.2 mm. Hemipenis width in the fully turgid state is about 2.3 mm. The retractor muscle is visible through the transparent hemipenis integument and bifurcates after about 1/2 of the hemipenis length. From the wide apex, two narrow tubular processes (0.5 mm in width) extend about 1.1 mm distally, with each end of the retractor muscle ending at the tip of these processes. The end of each of the tubes bears a distinct spine. The apex processes with their large spines are easily recognizable also in incompletely everted hemipenes ( Fig. 6 ). When the hemipenis is everted but not turgid (in preserved specimens), the processes are very distinct and project much more distinctly from the apex.

Etymology.— The species epithet is an adjective derived from the Latin ‘‘desperatus’’ meaning ‘‘desperate’’. Although the known range of the species is within a nature reserve established decades ago, its habitat is in truth barely protected and subject to numerous human-induced environmental problems resulting in severe habitat destruction [ 41], thus threatening the survival of the species.

Distribution.— Only known from the southern edge of Forêt d’Ambre Special Reserve, northern Madagascar.

Natural History.— All individuals were found roosting at night on small branches or leaves about 5–100 cm above the ground in disturbed rainforest. Individuals occurred in apparently high abundance and were also found at the border of forest clearings on banana plants. One female laid two large eggs when kept in a plastic bag. When stressed, individuals can quickly change colour and display a broad pale vertebral stripe contrasting with the darker flanks ( Fig. 9A ).

Figures

Figure 6. Hemipenes of species in the Brookesia minima group. The photos show for each species, a general view of the organs and a close-up. For B. desperata, the inset picture shows a non-turgid everted hemipenis where the two apex projections are very prominent. Note that also several other of the shown preparations are not fully turgid, especially in B. ramanantsoai and B. micra. In two other species (B. confidens and B. tristis) the shown hemipenes might not be fully everted. doi: 10.1371 / journal. pone. 0031314. g 006

Figure 7. Dorsal, lateral and ventral views of preserved male holotypes of newly described species. Scale bar equals 5 mm. doi: 10.1371 / journal. pone. 0031314. g 007

Figure 9. Life history and morphology of Brookesia desperata. (A) Female (displaying stress colouration) with two recently laid eggs. (B) Figure showing well-developed pelvic spine (1) and lateral spines on tail (2). doi: 10.1371 / journal. pone. 0031314. g 009