Another puzzle piece : new record of the Fringed Leaf Frog , Cruziohyla craspedopus ( Funkhouser , 1957 ) ( Anura : Phyllomedusidae ) , in the eastern Amazon Rainforest

We report new occurrence of Cruziohyla craspedopus (Funkhouser, 1957) in the eastern Amazon Rainforest. This is only the second record from the state of Pará, Brazil and represents the easternmost known point of this species’ range.

Cruziohyla craspedopus (Funkhouser, 1957) is an Amazonian phyllomedusid frog with a remarkable external morphology, presenting a bicolored iris, narrow dermal fringes on lower jaw and on the outer edge of the forearm, and well-developed fringes on the outer edge of tarsus, with three pointed flaps.The dorsal surface of the head, body and limbs is dark green punctuated with grayish white irregular blotches, and the ventral surfaces are bright orange, having six to eight vertical green bars in the flanks on a yellow background color (Funkhouser 1957;Hoogmoed & Cadle 1991).
On 2 October 2013, during a long-term search for amphibians and reptiles in the middle Tapajós River region, we found an amplectant pair of C. craspedopus with typical external morphology.The female was laying his eggs above a plastic bucket lid filled with rain water, which was part of a pitfall trap (04.7077° S, 056.4414°W, 70 m a.s.l., in the municipality of Itaituba, Pará).This site is located in a wellpreserved Terra Firme forest, never flooded by large rivers, inside the limits of a federal conservation unit, the Parque Nacional da Amazônia (in English, Amazon National Park).Specimens were collected under the Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis (IBAMA) collection permits #066/2012.We obtained their morphometric data based on measurements traditionally considered in anuran taxonomy, using calipers to the nearest 0.1 mm.We deposited the specimens in the Collection of Amphibians and Reptiles (INPA-H) of the Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, Amazonas, Brazil (accession numbers INPA-H 37436 and 37437).
The specimens were morphologically identified as C. craspedopus with the aid of the original description, taxonomic guides, and other geographic distribution notes for the Brazilian Amazon (Funkhouser 1957;Lima et al. 2003;Meneghelli et al. 2011;Rodrigues et al. 2011;Venancio et al. 2014;Bitar et al. 2015).We also compared our specimens with voucher specimens from the Brazilian Amazon (INPA-H 10936 and 10937, male and female, respectively).In addition, the reproductive behaviour observed by us is exactly as previously described (Hoogmoed and Cadle 1991;Block et al. 2003;Turell et al. 2016).
This new record of C. craspedopus (male specimen in Figures 1-3) provides additional morphometric information on Brazilian specimens (Table 1).It extends the geographic range of this species in eastern Amazonia: ca.2,250 km east from the type locality (municipality of Chicherota, Ecuador, 02.36° S, 076.63°W); 1,702 km northeast from the occurrence in Acre (Venancio et al. 2014); 860 km northeast from the occurrence in Rondônia (Meneghelli et al. 2011); 603 km northeast from the occurrence in Mato Grosso (Rodrigues et al. 2011); 408 km southeast from the occurrence in Amazonas (Lima et al. 2003); and 207 km northeast from the first record in Pará (Bitar et al. 2015).This record represents the easternmost known occurrence of the species (Figure 4).
This species may have a wider distribution in the Amazon than expected (Hoogmoed & Cadle 1991).The difficulty to locate C. craspedopus is strictly correlated with its life mode, as individuals of this species mainly inhabit the upper branches of tall trees or in the forest canopy and only descend to lower branches to reproduce; however, reproductive periods are unpredictable and may occur at different times throughout the year (Hoogmoed & Cadle 1991;Block et al. 2003).Furthermore, this species seems to have a high specificity of breeding habitats (Turell et al. 2016), which also influences its geographic range and abundance.Therefore, individuals of C. craspedopus are more easily found during the reproductive period (and rarely reported in short-term studies), or where they are most abundant.
Geographic distributions are indistinct for species inhabiting the upper strata of the Amazon Forest, such as the lizard Uracentron flaviceps (Guichenot, 1855) (de Freitas et al. 2011) or milk frogs of the genus Trachycephalus Tschudi, 1838 (Gordo et al. 2013), and the lack of knowledge is amplified for inconspicuous species, such as some small frogs of the Pristimantis lacrimosus group (Guayasamin et al. 2006).The increasing access to unexplored areas, long-term field inventories, and artificial breeding habitat studies (Turell et al. 2016) in the Amazon Rainforest may reveal additional localities of occurrence to C. craspedopus and clarify its conservation status in Brazil.Table 1.Measurements (in mm) of Cruziohyla craspedopus specimens recorded in the middle Tapajós River region: snout-vent length (SVL), forearm length from distal edge of hand to outer edge of flexed elbow (FAL), hand length from distal edge of hand to tip of finger III (HA), tibia length from proximal edge of flexed knee to heel (TL), foot length from proximal edge of inner metatarsal tubercle to tip of Toe IV (FL), head width at level of angle of jaw (HW), head length from angle of jaw to tip of snout (HL), eye diameter (ED), internarial distance (IN), interorbital distance (IO), eye-nostril distance (EN), snout length (SL), tympanum diameter (TD), finger III disc width (WFD), toe IV disc width (WTD), and thigh length (THL).