New records and distribution extensions of centrolenid frogs for Venezuela

: We report the first record of Centrolene notostictum for Venezuela, the first records of Centrolene venezuelense and Hyalinobatrachium pallidum for Zulia state, and extend the distribution of Hyalinobatrachium tatayoi and Espadarana andina based on specimens coming from the eastern versant of the Sierra de Perijá in northwestern Venezuela. The altitudinal ranges of all species are extended, and comments and notes on natural history provided.

The morphology of the specimens of Hyalinobatrachium pallidum from Perijá agrees with the original description (Rivero 1985), except for the color of the pericardium and the relative length of fingers I and II. Rivero (1985) defines the pericardium as "no blanco" (not white) in the diagnosis and description; subsequently, in the same paper (p. 360) comments that "el corazón del animal vivo se ve rojo y pulsante" (the heart of the live animal looks red and pulsating). However, in the redescription provided by Señaris and Ayarzagüena (2005), based on the type series and an additional topotype, the color of the pericardium was described as light golden in life. All specimens from Perijá have light golden pericardium in life ( Figure 6B), and nacreous in preservative. Rivero (1985) states that fingers I and II are similar in length; nevertheless in the section of variation Rivero mentions that the specimen UPR-M 5561 (now MHNLS 15117), a topotype tentatively assigned to H. pallidum, has finger I slightly larger than II. Señaris and Ayarzagüena (2005), redefine this character as: finger I = II, or slightly longer than II. Specimens from Perijá have finger I slightly longer than finger II. Señaris and Ayarzagüena (2005) refer to H. pallidum as a mediumsized frog, with snout-vent length (SVL) in adult males 21.9-22.4 mm (females unknown). The specimens of Perijá reach slightly greater sizes: males 21.2-25.0 mm (23.0 ± 0.9; n = 26) and females 23.0-24.8 mm (23.8 ± 0.7; n = 4). Finally, in addition to the typical densely punctuated dorsal pattern of H. pallidum (Rivero 1985;Señaris and Ayarzagüena 2005), most of the specimens from Perijá also exhibit irregular black flecks (dark purple in preservative) on the dorsum, head, and dorsal surfaces of the limbs. This condition is very variable, ranging from numerous flecks (e.g. MHNLS 18832 and 18881) to no flecks (e.g. MHNLS 19219, 19221). Also, MHNLS 18880 shows an atypical color pattern, with some dark flecks and several light blotches on the dorsum (seen under magnification to correspond to areas without melanophores). The descriptions of Rivero (1985) and Señaris and Ayarzagüena (2005) do not mention the presence of dark flecks and/or dorsal light blotches in the specimens examined but they are present in the photograph of a topotype provided in Guayasamin et al. (2009). We consider that this color variation is due to intraspecific variation. It is evident that morphological variation in H. pallidum is greater than previously described, and therefore this species will require a new redescription. The two localities in the Cerro Las Antenas ( Figure  6C) and Campamento Guacharaca ( Figure 2B) are small fast-flowing creeks surrounded by primary cloud forest, with abundant stream-side vegetation (ferns, Heliconiaceae, Araceae and Cyclanthaceae). In these localities Hyalinobatrachium pallidum was abundant, and besides the specimens collected numerous males were calling from the underside and upper side of leaves, and guarding their egg masses on the undersides of the leaves of Heliconiaceae, Araceae and Cyclanthaceae plants. The locality of Manastara is a small creek in secondary forest with shaded coffee plantations. In this locality, H. pallidum was scarce while other syntopic centrolenids (Centrolene daidaleum and Espadarana andina) were abundant.
Hyalinobatrachium pallidum is classified as Endangered in the IUCN Red List of Threatened Species (La Marca and Manzanilla 2004), because its extent of occurrence was less than 5,000 km 2 (previously known from a single locality), and there is continuing decline in the extent and quality of its habitat at the type locality (La Marca and Manzanilla 2004). However, the new localities in the Venezuelan Sierra de Perijá significantly increase its distribution.   San Isidro (08°50'05" N, 70°34'41" W; 1,500 m), Estado Barinas, Venezuela. The specimen could not be examined but if it is H. pallidum, this would indicate that the species is also present on the eastern versant of the Cordillera de Mérida, and its range is much greater than previously known. Additionally, two populations (Manastara and Campamento Guacharaca) occur inside the PN Sierra de Perijá, so a reassessment of the conservation status of this species is required.
Hyalinobatrachium tatayoi (Figures 7A-B) is only known from its type locality, a stream near El Tokuko,  Castroviejo-Fisher et al. (2007) also comment on the abundance of the species at the type locality (several km downstream on the same river) during July 2005. At Ipika, in September 2008, two months after a heavy rainy season that caused major flooding and landslides, which devastated almost all stream-side vegetation and modified the physiography of the river, only three specimens of H. tatayoi were detected during nocturnal surveys. These natural disasters have increased in frequency and intensity as consequence of the deforestation of watersheds in the piedmont of Perijá and can severely affect the population dynamic of this riparian species, perhaps even causing local extirpations.
Hyalinobatrachium tatayoi is distinguished from H. fleischmanni (Boettger, 1892) almost exclusively by the presence in the former, of enamelled glands in the skin covering the jaw and the lower part of the upper lip (Castroviejo-Fisher et al. 2007). Recent genetic analysis indicated that these two species are closely related  and that H. tatayoi is probably a synonym of H. fleischmanni ); however, the datasets were insufficient to resolve this problem. To this respect Castroviejo-Fisher et al. (2009) mentioned that the taxonomy of these species should be reevaluated using a large and geographically widely distributed sample to detect lineage divergence. Hyalinobatrachium tatayoi is categorized as "Least Concern" by the IUCN Red List (Castroviejo-Fisher 2008); however, its known extent of occurrence is restricted to the piedmont of the Venezuelan versant of Perijá (less than 5,000 km 2 ), and part of its habitat is affected by deforestation, so its conservation status could change in the near future. Clarifying the taxonomic uncertainty of H. tatayoi is crucial in order to properly reassess the conservation status of this species and to design management and conservation measures as required.
With the new records, the number of glassfrog species known from Perijá increases to six, making this region the most rich in centrolenids in the Venezuelan Andes. Only five glassfrogs are know from other mountain systems of the Venezuelan Andes (Cordillera de Mérida and Macizo del Tamá): C. altitudinale (Rivero, 1968), C. venezuelense, E. andina, H. pallidum and H. duranti (Rivero, 1985) (Señaris and Ayarzagüena 2005). Of the six species present in Perijá, only one (16.7%) is endemic (H. tatayoi), two (33.3%) are shared with the rest of the Venezuelan Andes (H. pallidum and C. venezuelense), two others are shared with the Cordillera Oriental of the Colombian Andes (C. daidaleum and C. notostictum), and one (16.7%) is shared with both Colombian and Venezuelan Andes (E. andina). Thus, the Sierra de Perijá shows affinities with both neighboring mountain systems regarding centrolenids frogs (Table  1). Curiously, Perijá does not share any glassfrog species with the nearby Serranía de Santa Marta, from which it is separated by the narrow valley of the Ranchería river.
The Sierra de Perijá remains poorly explored; however, our discoveries and others (Barrio-Amorós et al. 2007;Infante-Rivero et al. 2008;Rojas-Runjaic et al. 2010;2011) document the diverse amphibian fauna in this region. New expeditions undoubtedly will result in the discovery of new species, and consequently, in a better understanding of the diversity of the Sierra de Perijá, and its biogeographical affinities with neighboring bioregions. Figure 9. Richness, composition and altitudinal distribution of the glassfrog communities at ten localities in the Sierra de Perijá, ordered from north (left) to south (right).