Ranitomeya cyanovittata, Perez-Peña, Pedro E., Chavez, German, Twomey, Evan & Brown, Jason L., 2010

Perez-Peña, Pedro E., Chavez, German, Twomey, Evan & Brown, Jason L., 2010, Two new species of Ranitomeya (Anura: Dendrobatidae) from eastern Amazonian Peru, Zootaxa 2439, pp. 1-23 : 12-16

Ranitomeya cyanovittata sp. nov.

Figures 8 , 10

Holotype. CORBIDI 0 2266 ( Fig. 10 A), an adult female collected by Diego Vasquez in the Rio Blanco Basin near the Zona Reservada Sierra del Divisor, Departamento Loreto, Peru; 6º55’12”S, 73º50’45W, 206 m elevation; September 2008.

Paratype. CORBIDI 0 2991 ( Fig. 10 B), an adult male collected by Diego Vasquez in the Rio Blanco Basin near the Zona Reservada Sierra del Divisor, Departamento Loreto, Peru; 6º54’57”S, 73º50’45”W, 257 m elevation; December 2008.

Etymology. The specific epithet, an adjective, means ‘blue striped’ and is formed from the combination of the ancient Greek noun “κυανοσ” (or “ cyanos ”) for “a blue substance used to adorn armor in the Heroic age” and the Latin adjective “ vittatus ” for “banded.”

Definition and diagnosis. Assigned to the genus Ranitomeya due to the combination of the following characteristics: small size (<18 mm SVL), first finger distinctly shorter than second, dorsal coloration conspicuous and bright, dorsal skin smooth, toe webbing absent, maxillary and premaxillary teeth absent, pale limb reticulation present. Ranitomeya cyanovittata is a relatively small species of Ranitomeya , adult SVL of approximately 13.8–17.3 mm. Bicolored pattern bright blue and black; teeth absent; finger I shorter than finger II; disc of third finger 1.9–2.2 times wider than finger width.

Ranitomeya cyanovittata can be distinguished from all other dendrobatids by its distinctive bicolored pattern of a black background with turquoise-blue lines or reticulations over the entire body (dorsal and ventral side). Six other species of Ranitomeya have a bicolored pattern. Ranitomeya fulgurita ( Silverstone, 1975) ranges from Panama to Northwestern Colombia and is bicolored dorsally and ventrally, but this pattern consists of a greenish-yellow body with black stripes or spots ( Lötters et al., 2007). Ranitomeya abdita from southern Ecuador ( Myers & Daly, 1976) has a solid dark bronze to black body with orange spots on the posterior areas of the upper arm and thigh ( Lötters et al., 2007). Ranitomeya altobueyensis from the Serrania de Baudó in Colombia ( Silverstone, 1975) has a uniform yellow or golden metallic body (sometimes with a greenish hue), occasionally with small black spots on the dorsum and often on the venter ( Lötters et al., 2007). Ranitomeya dorisswansonae from the Cordillera Central in Tolima, Colombia ( Rueda-Almonacid et al., 2006) has a dark brown or reddish brown background with irregular red to yellowish-orange spots that may be absent on the limbs ( Lötters et al., 2007). Ranitomeya sirensis from the Cordillera El Sira in Central Amazonian Peru ( Aichinger, 1991) has a red dorsum with turquoise-green legs and arms, a turquoise-green venter with a red patch on the belly, and lacks dorsal reticulations or spots ( Lötters et al., 2007). Finally, Ranitomeya summersi from Central Amazonian Peru has a black ground color with orange stripes on the dorsum and venter (Brown et al., 2008).

Ranitomeya cyanovittata is most similar in appearance to the following species: Ranitomeya biolat , R. flavovittata , R. imitator , R. lamasi , and R. ventrimaculata . Ranitomeya biolat and most lowland populations of R. imitator possess yellow dorsal stripes (vs. blue stripes in R. cyanovittata ); R. flavovittata has broken, irregular, yellow dorsal stripes (vs. unbroken blue stripes in R. cyanovittata ); R. lamasi has dorsal stripes which can be green, yellow, orange, or red (but never blue as in R. cyanovittata ) and typically has a yellow patch on the belly (vs. patch absent in R. cyanovittata ). Ranitomeya ventrimaculata has yellow dorsal stripes that are not parallel (vs. blue stripes parallel in R. cyanovittata ).

Measurements (in mm) of holotype. The female holotype ( Fig. 10 A) has SVL 17.3; FL 6.5; TL 6.8; KK 13.3; FoL 6.4; HaL 4.2; HL 5.1; HW 5.6; BW 6.4; UEW 1.2; IOD 2.6; IND 2.0; TD 0.46; ED 1.7; DET 0.48; L1F 1.77; L2F 2.28; W3D 1.09; W3F 0.53. Paratype measurements ( Fig. 10 B): SVL 13.8; FL 5.5; TL 6.1; KK 11.7; FoL 5.09; HaL 3.6; HL 3.6; HW 3.9; BW 3.9; UEW 0.94; IOD 2.0; IND 1.7; TD 0.35; ED 1.3; DET 0.35; L1F 1.28; L2F 1.85; W3D 0.56; W3F 0.26.

Description of holotype. Widest part of head at jaw articulations. Head slightly narrower than body. Tongue ovoid; teeth absent. In life, head black with blue spot in pit of snout, transverse blue stripe between eyes extending through upper eyelid anterior to upper insertion point of thigh; labial stripe extends to upper insertion of arm. Dorsum black with a vertebral line from posterior region of head to vent. Weakly-defined spot present on dorsal surface of axilla. Arms, legs, and toes are covered in a pale reticulations on a black background color, creating round black spots. Underside of head with lateral gular spots, creating the appearance of an hourglass. Venter black with blue irregular reticulation, creating black spots, much like the limbs.

In life, skin texture nearly smooth on the dorsal surfaces of the body and head; limbs and rump weakly granular. Venter weakly granular on limbs and body, ventral surface of head nearly smooth. Snout sloping and rounded in lateral profile, round or slightly blunted in dorsal profile. Nares situated at tip of snout and directed laterally; both nares visible from ventral and anterior view but not from dorsal view. Canthus rostralis rounded, loreal region flat and nearly vertical. Upper eyelid approximately equal in width to interorbital distance; internarial distance roughly equal to eye width. Tympanum round, partially concealed posterodorsally.

Hands relatively large, length 24.5 % of SVL. Relative length of appressed fingers III> IV> II> I; first finger 77.6 % length of second; finger discs moderately expanded, width of disc on finger III 2.05 times width of adjacent phalanx. An unpigmented median metacarpal tubercle is present on base of palm; inner metacarpal tubercle present near base of finger I; unpigmented proximal subarticular tubercle present on base of each digit, except on finger I, where tubercle is part-way up the digit; distal subarticular tubercle visible only on fingers III and IV. All tubercles raised above level of hands; scutes present on dorsal surface of fingers.

Hind limbs moderate length, with heel of appressed hind limbs reaching level of eye. Femur and tibia roughly equal in length, tibia 99.1 % length of femur; knee–knee distance 77 % of SVL. Relative lengths of appressed toes IV> III> V> II> I; first toe short with unexpanded disc; second toe with slightly expanded disc, discs on toes III–V moderately expanded. Two unpigmented metatarsal tubercles present on base of foot, one situated medially near base of toe I, the other situated laterally at the base of the fifth metatarsal. Proximal subarticular tubercles present at base of each toe but most notable on toes I and II due to their lack of pigmentation. Toes III and V with two subarticular tubercles, toe IV with three subarticular tubercles. A tarsal keel is present starting below the knee and turning into the medial metatarsal tubercle at the foot. Tarsal tubercle absent; feet and hands lacking webbing and lateral fringing.

Color in life: Dorsal body, legs, and head are black with blue longitudinal irregular stripes; a longitudinal, bright blue stripe is present from the tip of the labial region to the insertion point of the arms, a blue lateral stripe is present from the armpit to the groin. There is a weakly-defined pale blue spot on the dorsal surface of the axilla. The arms, legs, and toes are covered in pale blue reticulations on a black background color, creating round black spots; toes are blue-black. Underside of head blue with lateral black gular spots, creating appearance of a blue hourglass. Lower lip blue. Venter black with blue irregular spots, creating black spots, much like the limbs. Limbs are brownish. Iris black.

Color in preservative. In preservative, coloration is identical to color in life, with the exception of blue coloration being grey.

Distribution and natural history. Ranitomeya cyanovittata is known only from two sites near Nueva Capanahua community, in the Rio Blanco basin near the Sierra del Divisor, between 200 and 300 m elevation ( Figs. 1 and 11 ). This species inhabits undisturbed upland forests near small streams and rivulets ( Fig. 12 ). The vegetation consists principally of the following trees: Moronobea spp., Cedrella spp., and Cedrelinga cateniformis . Lianas are common but were not noted to occur in dense tangles. At ground level, vegetation was sparse, with some ferns and other large, herbaceous plants (such as Heliconia spp.). Bromeliads were not recorded. The leaf litter was sparse and appeared dry after several rainless days. The two individuals observed were foraging in leaf litter ( Pers. Comm. Diego Vasquez): this is notable because other members of Ranitomeya vanzolini group are almost always found within or upon some sort of plant (e.g. Heliconia, Xanthosoma , or Dieffenbachia ). Both specimens were encountered during the day and were sympatric with Ameerega ignipedis and A. cf. hahneli : of these species, Ameerega ignipedis was abundant and was frequently observed during the day in the leaf litter ( Pers. Comm. Diego Vasquez). Neither courtship nor other behavioral characteristics were observed in R. cyanovittata .

Conservation status: Following the IUCN Red List criteria ( IUCN 2001), this species should be listed as Data Deficient (DD). Being known from only from two localities that are less than 1 km apart, its extent of occurrence is unknown.

Figures

FIGURE 1. Map of study areas. Lago Preto, the type locality of R. yavaricola sp. nov., is depicted by a yellow dot. Nueva Capanahua community, the type locality of R. cyanovittata sp. nov., is depicted by a blue dot.

FIGURE 8. Distributions of Ranitomeya that occur within the forests bordered by the Ucayali, Amazon, Yavarí, and Blanco rivers. The blue color depicts areas that are prone to flooding or that are permanently flooded. These areas likely act as barriers to gene flow for most Ranitomeya species. Each colored circle represents the corresponding species at each site. The white dot depicts the only known locality of the R. cyanovittata. The area that becomes seasonally flooded was calculated from two data sources: areas classified as Várzea by the World Wildlife Foundation (Olson et al. 2001) and spatial calculations in Environmental Systems Research Institute’s GIS ArcView 9.2 that estimated the seasonally flooded areas. The latter was done by calculating the feet above sea-level of major streams that seasonally flooded throughout the area. These values were kriged to create a raster that accounted for elevation changes relative to level of the major rivers. The resulting raster was subtracted from a digital elevation model, and areas below 10 meters were classified as “ seasonally flooded ”.) Both the Varzea and “ floodable ” areas were summed to create the blue layer area depicted here. Ten meters is an average the annual fluctuation in river levels for the lower Ucayali, upper Amazon, and lower Yavari rivers (Goulding et al. 2003).

FIGURE 10. Left column (A), dorsal and ventral view of the female Ranitomeya cyanovittata (CORBIDI 0 2266, holotype, SVL 17.3 mm); Right column (B), dorsal and ventral view of the male Ranitomeya cyanovittata (CORBIDI 0 2991, paratype, SVL 13.8 mm). Photographs by Diego Vasquez.

FIGURE 11. View of the Rio Blanco basin near the type locality of R. cyanovittata, Loreto, Peru. Photograph by Diego Vasquez.

FIGURE 12. Habitat of Ranitomeya cyanovittata. Photograph by Diego Vasquez.