Ranitomeya tolimense, Bernal, Manuel Hernando, Luna-Mora, Victor Fabio, Gallego, Oscar & Quevedo, Alonso, 2007

Bernal, Manuel Hernando, Luna-Mora, Victor Fabio, Gallego, Oscar & Quevedo, Alonso, 2007, A new species of poison frog (Amphibia: Dendrobatidae) from the Andean mountains of Tolima, Colombia, Zootaxa 1638, pp. 59-68 : 60-66

Ranitomeya tolimense sp. nov.

( Fig. 1 , 2 )

Holotype: ICN 53372, an adult male, collected by Oscar Gallego, Victor Luna and Manuel H. Bernal on 19 May 2007 near “Finca La Lulera”, vereda el Llano, Departamento del Tolima, Municipio de Falan, Cordillera Central of Colombia, elevation 1852 m above sea level (5º01’08”N, 75º02’31”W) ( Fig. 3 ).

Paratypes: ICN 53373, adult female; CZUT-A 988-989, adult females; CZUT-A 990-991, adult males; collected along with the holotype.

Etymology: The specific epithet means “from Tolima”, the department of Colombia where the new species was found.

Definition and diagnosis: Ranitomeya tolimense is a dendrobatid having an adult SVL of 17.66–18.92 mm. Dorsal surfaces in life brown or dark brown, anteriorly with a moderate metallic yellow-bronze color that ends posterior to the head and gradually after the midbody. Ventral surfaces in life overall brown dark, with or without bluish green spots or speckling on belly, undersides of thighs and groins. The skin is granular on the dorsum, flanks, venter and the dorsal surface of the limbs, and comparatively less granular on the forelimbs. A brown dark stripe extends from the outer border of the eyes, crossing the tympanum, to the forelimbs insertions, which contrasts with the yellow color of the upper jaw. The proximodorsal surface of the upper arm is yellow. Fingers are webless; adpressed first finger shorter than second; third finger disc of adults about 1.5– 2.0 times wider than distal end of adjacent phalanx, discs on fingers notably expanded. Digits of feet lacking webbing or lateral fringe; toe I shorter than toe II, and unexpanded toe discs.

Ranitomeya tolimense is considered to be related to R. abdita , R. bombetes , R. opisthomelas and R. virolinensis based on shared larval characters, proposed to represent synapomorphies by Myers & Daly (1980). The character state is the median gap that interrupts the papillae fringe on the lower edge of the oral disc. The new species can be distinguished from these four species by the dorsal color: R. abdita is unicolor dark bronzy brown with orange flash marks proximally on the arms and legs adjacent to axilla and groin; R. bombetes is black with dorsolateral stripes yellowish or orange golden; R. opisthomelas and R. virolinensis are largely red turning gray distally on limbs and dark brown after two-third of body, respectively. R. tolimense is syntopic with R. dorisswansonae , but readily distinguished by color pattern and morphology since the latter is dark brown or black with irregular red blotches, and the toes I and II are partially or totally fused (not so in the new species described herein).

Measurements of holotype (mm): SVL 17.66; TL 7.98; GBW 8.13; greatest HW 5.97; IOD 2.35; HL 5.04; TSCN 1.55; NED 1.36; IND 2.52; EL 2.32; HDT 1.18; MTD 1.02; HaL 4.65; WTFD 0.80; WTF 0.40; WTTD 0.64; WTT 0.61; WFTD 0.50; WFT 0.45.

Description of the type series (3 adult males, 3 adult females): Size small, with maximum SVL of 18.91 ( Table 1 ); females slightly larger than males ( Table 2 ). Head narrower than body; greatest HW 73 % of GBW in males, and 79 % in females. Greatest HW averaging about 30 % of SVL ( Table 2 ). Males with defined vocal slits, but with little or not external indication of the subgular vocal sac. Snout weakly pointed to truncate in dorsal and ventral aspects. Nares situated near tip of snout and visible from front and from below but not from above. Canthus rostralis rounded, loreal region flat, inclined slightly outward to lip. Eye longer than snout length; distance from center of naris to eye 65 % of EL in males and 64 % in females ( Table 2 ). Tympanum vertically oval, smaller than eye.

Hand ( Fig. 4 A) moderately large, its length (proximal edge of metacarpal tubercle to tip of longest finger) about 23.5–26.7 % of SVL. Relative length of adpressed fingers III> IV> II> I; adpressed finger I shorter than finger II and its tip just reaching disc of second. Discs slightly expanded on finger I, but notably expanded on fingers II, III and IV; third finger disc in females and males averaging 1.59–1.86 times wider than distal end of adjacent phalanx. A large circular outer metacarpal tubercle on median base of palm, an smaller inner metacarpal tubercle on base of finger I, and one tubercle on base of fingers I and II, and two tubercles on fingers III and IV.

Hind limbs relatively long; tibia 40–45 % of SVL. Relative lengths of adpressed toes IV> III>V>II> I; toe I short ( Fig. 4 B), reaching bottom of subarticular tubercle of toe II, and with unexpanded disc. Other toe discs slightly expanded. One to three nonprotuberant subarticular tubercles, one on toes I, II, two on toes III and V, and three on toe IV. Small outer and moderately-sized inner metatarsal tubercles. Feet lacking webbing or lateral fringes.

Coloration: In life ( Fig. 1 ), head yellow-bronze, upper jaw and anteroproximal part of the upper arm bright yellow; venter, throat, chest, sides of the body, hind limbs and hands brown or black brown. A dark stripe extends from the eyes to the arm insertion. Throat and venter with or without small bluish green blotches; flanks, groin and thighs (anterior and ventral) with or without a few bluish spots. Iris dark brown.

In 70 % alcohol the dark or dark brown surfaces of the body maintain their color, as well as the bluish green of blotches or spots of ventral surfaces. However, the bronze color of head become dark whereas the yellow color of the upper arm and jaw change to a pale white and later to a dark gray.

Sexual dimorphism: The most remarkable external characteristics to differentiate adult males and females are the presence of vocal slits. Also, a wider disc on finger III and a smaller SVL was found in males ( Table 2 ); however, there are a few data to be confident with this sexual difference. Testes and eggs are dark brown.

Distribution and natural history: So far, R. tolimense is known only from the type locality on the eastern flank of the Cordillera Central, Municipio de Falan, Departamento de Tolima, Colombia. Specimens were collected at an elevation of about 1852 m above sea level. They were found during day and the onset of night time in May 2007 on the forest floor. On 19 May 2007, at 18:00 h (relative humidity: 75 %, air temperature: 20.4 ºC), we found a male nurse frog carrying a tadpole on his back on the ground near bromeliads and heliconias. When captured the frog expelled a milky secretion over his body ( Fig. 2 ).

The type locality of R. tolimense is a small patch of a secondary forest dominated by trees with a maximum height of 4 to 6 m, covered by epiphytic plant, mainly of the families Araceae , Bromeliaceae and Orchidaceae . The canopy is dense allowing for little penetration of light. Humidity in the area is maintained by the constant cloud cover and frequent rainfall. The forest floor is covered by leaf litter, fallen tree branches and trunks, house to fungi, mosses and lichens. There are also smaller trees, palms and tree ferns. The mean temperature is about 19 ºC and the annual precipitation is between 2500–3000 mm per year ( Gallego, 2003).

The general area is dominated by farms with coffee plantations, most likely not suitable habitat for R. tolimense . We recommend further studies to assess the distribution of this species and its conservation status.

Tadpole: The following description is based on a larva (CZUT-A: 991) obtained from the back of a nurse frog male ( Figs. 2 , 5 ). The larva is in stage 25 sensu Gosner (1960).

Measurements in millimeters are: head-body length 4.4; total length 13.1; tail length 8.7; greatest depth from upper edge dorsal fin to lower edge ventral fin 1.3.

The tadpole has a globular shape when viewed from above, with maximum body width of 61 % of head body length. The head and body are depressed, width much greater than depth; eyes and nostrils are dorsal, directed dorsolaterally; the spiracle is sinistral and low and the anus dextral ( Fig. 5 A). The tail is 64 % of the total length and its maximum tail height is only 9.9 % of total length. The tip of the tail is rounded ( Fig. 5 A).

The mouth is directed anteroventrally. There are two upper and three lower tooth rows, with the second upper row being broadly broken above the beak ( Fig. 5 B). The other rows are complete, although the third posterior one row is weakly pronounced, probably due to an ontogenetic difference with respect to other tadpoles found in the locality. The beak is massive, with serrate cutting edges. The oral disc is laterally indented and its posterior edge has a broad median gap ( Fig. 5 B). This gap is shared with other related species of the genus Ranitomeya as mentioned above and perhaps represents a synapomorphy ( Myers & Daly, 1980), although R. bombetes has a somewhat broader median gap and larger and fewer labial papillae than R. abdita , R. opisthomelas ( Myers & Daly, 1980), R. virolinensis ( Ruiz-Carranza & Ramirez-Pinilla, 1992) and R. tolimense . Furthermore, R. tolimense shares with R. virolinensis one to two rows of labial papillae ( Figure 5 B), whereas the illustrations of the other species shown apparently just one.

Life coloration was brown to dark brown, lighter on ventral side, turning clear towards the tail tip. In 10 % formalin, the body and tail are pale brown, uniformly pigmented, including fins. The tail tip is somewhat transparent and the venter translucent.

Vocalization: The advertisement call of R. tolimense ( Fig. 6 ) is a series of short buzzes of 0.84–0.99 seconds (N = 6). The call is pulsed throughout its length with a dominant frequency of about 4.73–5.22 kHz. The call is heard as a short, soft cricket-like buzz and sounds similar to the syntopic Ranitomeya dorisswansonae , although not as loud as it.

The buzz call (sensu the defined of Lötters et al., 2003) as described herein for R. tolimense is similar to buzz calls described to species considered sharing larval characters with the new species, i.e. R. bombetes , R. opisthomelas ( Myers & Daly, 1980) , R. virolinensis ( Amézquita, 1995) , and likely R. adbita ( Myers & Daly, 1980) . We will not rule out but can’t claim here that similarities in advertisement calls are due to close phylogenetic relationships. First, buzz calls have been reported in other dendrobatid frog species (see Lötters et al., 2003), and second, anuran vocalizations are considered highly adaptive traits.

Remarks: According to the possible larval synapomorphy suggested by Myers & Daly (1980) and perhaps morphological and vocalization characters, R. tolimense is expected to be a member of an Andean monophyletic dendrobatid clade including R. abdita , R. bombetes , R. opisthomelas and R. virolinensis . Larvae of other Ranitomeya lack a median gap in the papillae fringe on the lower edge of the oral disc (e.g. R. minuta , R. fulgurita , R. altobuyensis ) or remain unknown ( R. viridis , R. daleswansoni , R. dorisswansonae ).

Figures

FIGURE 1. Ranitomeya tolimense, new species. Lateral view showing color pattern. CZUT-A 989 adult female, SVL 17.94 mm. Photo: Manuel H. Bernal.

FIGURE 2. Male nurse frog (CZUT-A 990) with a tadpole over his back at the type locality. Photo: Victor Luna.

FIGURE 3. Map of Colombia showing (arrow) the type locality of Ranitomeya tolimense.

FIGURE 4. Ventral view of hand and foot of Ranitomeya tolimense (CZUT-A 989). Scale = 1 mm.

FIGURE 5. Tadpole of Ranitomeya tolimense (CZUT-A 991). (A) Lateral view, stage 25 (Gosner, 1960). Scale equals 5 mm. (B) Mouth parts. Scale equals 1 mm.

FIGURE 6. Advertisement call of Ranitomeya tolimense. A. Audiospectrogram of a call with three notes. B. Oscillogram of the three notes showing the pulses.

Tables

TABLE 1. Measurements (in mm) for the type series of Ranitomeya tolimense, new species.

	ICN 53373 Adult female	CZUT-A 988 Adult female	CZUT-A 989 Adult female	ICN 53372 Adult male	CZUT-A 990 Adult male	CZUT-A 991 Adult male
SVL	18.91	17.82	18.11	17.66	17.95	18.02
TL GBW	7.94 8.16	7.14 6.93	7.53 7.08	7.98 8.13	7.22 7.35	7.73 6.52
HW	5.86	5.42	5.64	5.97	5.81	5.35
IOD HL	2.27 5.65	2.25 4.97	2.36 5.14	2.35 5.04	2.16 5.08	2.19 5.46
TSCN	1.74	1.31	1.57	1.55	1.38	1.89
NED IND	1.52 2.40	1.44 2.22	1.35 2.34	1.36 2.52	1.65 2.33	1.38 2.19
EL	2.23	2.19	2.24	2.32	2.20	2.20
HDT MTD	1.44 0.85	1.13 0.64	1.27 0.87	1.18 1.02	1.10 0.91	1.33 0.94
HaL	4.57	4.30	4.22	4.65	4.52	4.10
WTFD WTF	0.73 0.48	0.64 0.40	0.65 0.39	0.80 0.40	0.75 0.46	0.78 0.40
WTTD	0.60	0.58	0.56	0.64	0.60	0.71
WTT WFTD	0.55 0.64	0.50 0.48	0.44 0.46	0.61 0.50	0.54 0.44	0.54 0.38
WFT	0.48	0.42	0.36	0.45	0.40	0.32

TABLE 2. Size and proportions of adult Ranitomeya tolimense, New species sensu Myers & Daly (1980).

Measurements	N	Mean (+/- S.E.)	Stand dev.	C.V. (%)	Range
SVL	3 males 3 females	17.87 (0.11) 18.28 (0.22)	0.190 0.564	1.06 3.06	17.66–18.02 17.82–18.91
TL/SVL	3 males 3 females	0.42 (0.02) 0.41 (0.01)	0.010 0.005	4.76 2.42	0.45–0.40 0.40–0.41
HL/SVL	3 males 3 females	0.30 (0.00) 0.30 (0.01)	0.011 0.002	3.66 0.66	0.28–0.32 0.30–0.31
NED/EL	3 males 3 females	0.65 (0.04) 0.64 (0.02)	0.0.8 0.04	12.30 6.25	0.58–0.75 0.60–0.68
WTFD/WTF	3 males 3 females	1.86 (0.11) 1.59 (0.04)	0.20 0.07	10.75 4.40	1.63–2.00 1.52–1.66