Introduction

Ecuador has the biggest number of amphibian species per unit of area in the world (425 species in 276,840 km2). In the last decade several sources of data suggest that a significant proportion of this biodiversity is endangered. Conservative estimates indicate that at least 26 species of Ecuadorian amphibians have declined or gone extinct. The reasons for this crisis are not clear but have been related to habitat destruction, climate change, and/or disease such as Chytridiomycosis.

The Río Palenque Science Center (RPSC) was among the last remnants of tropical rainforest in the western lowlands of Ecuador. 20 year ago, investigations done by R. McDiarmid & K, Miyata lead to the discovery of an amazing herpetofauna, including undescribed species (e.g. Lepidoblepharis grandis Miyata 1985). However, the expansion of the agricultural frontier and transformation of the forest remnants into oil palm and banana plantations destroyed this site. Among the species identified from RPSC were five species of glass frogs (Family Centrolenidae). Glass frogs belong to the Neotropical family Centrolenidae, which currently comprises the genera Centrolene, Cochranella, and Hyalinobatrachium. Most of them are small frogs (20-30 cm) and differ from other Anura by the fusion of the astragalus and calcaneum, T-shaped terminal phalanges, and a process on the third metacarpal. Currently, there are 31 species of glass frog registered in Ecuador, nine of which are endemic.

Two species of Centrolenidae from RPSC are undescribed. This research analyzed the morphological characters and natural history of the five glass frogs of RPSC in order to describe one of the new species of the genus Centrolene from RPSC which is critically endangered, if not extinct.

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Materials & Methods

Standard measurements of all specimens were made to the nearest 0.1 mm using dial calipers. Webbing formula notation follows Savage & Heyer (1967) as modified by Myers & Duellman (1982). The nuptial pad terminology follows Flores (1985) and Lynch & Ruiz-Carranza (1996). Calls were analyzed with the CANARY program in the sound laboratory of the Division of Amphibians and Reptiles, National Museum of Natural History, where the tapes recordings are deposited. The specimens are deposited at the National Museum of Natural History (USNM) and at the Museum of Comparative Zoology, Harvard University (MCZ).

The analysis of the conservation status was based on the categories and criteria proposed by IUCN (2001) to determine the degree of threat of the species and following the basic format established in the book "Threatened birds of the world" (BirdLife International 2001).

The data presented in a study of priority areas for the conservation of biodiversity in Ecuador (Sierra et al. 1999) were used to evaluate the conservation status at the ecosystemic/vegetal formation level. Four of the five criteria used by Sierra et al. (1999) for each vegetal formation were used: level of representation in the Ecuadorian national system of protected areas (SNAP), level of human pressure, percent of remnant ecosystem, and ecosystemic diversity. These four criteria were based on the excellent work about a preliminary classification of the vegetal formations of Ecuador (Sierra 1999) along with a geographical information approach, which led them to give useful data about the current status of the ecosystems/vegetal formation of Ecuador.

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Study Area

Rio Palenque Science Center

Rio Palenque Science Center is located in the Province of Los Rios, Ecuador. It lies on the at 300 m over the sea level. This locality is in the contact zone of the Northwestern and Southwestern Tropical zoogeographic floors (Albuja et al. 1980), and Central Coast Lowlands Evergreen Forest vegetal regimen (Valencia et al. 1999).

Centrolenidae of Rio Palenque Science Center

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Hyalinobatrachium fleischmanni

This species is still fairly common in suitable habitats. It was found at RPSC living in the surrounds of ravines and streams. There is still some confusion among the systematic position and separation among this species and H. petersi.

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Centrolene prosoblepon

A species that is still seen frequently in the lowland Ecuadorian streams. It is polymorphic, with a black-spotted and a yellow-dotted form sympatric at RPSC. Aggressive behavior due to strong territoriality is shown by the males, mostly because its reproductive mode require limited resources.

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Cochranella spinosa

A particular species, it was previously thought the only one with an exposed prepolicall spine. However with the description of Centrolene litoralis and the discovery of C. miyatai sp. nov., this character seems to be much extended.

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Hyalinobatrachium sp. nov.

This beautiful glass frog was initially confused with H. valerioi, however the color in life of the dorsum and the presence of a bare pericardium (vs. white pericardium in H. valerioi) let us to differentiate these species.

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Centrolene sp. nov.

A Critically Endangered Species

Diagnosis. This new species of Centrolene is easily distinguished from other glass frog species by a combination of the following features:

1) presence of an exposed prepollical spine

2) presence of a humeral spine in the males

3) presence of a distinctive glandular nuptial pad at the base between the I and II finger

4) coloration in life with two yellow dorsolateral stripes over a greenish dorsum, some scattered black spots, and yellow discs of fingers and toes.

The conservation status analysis of this species lead us to believe that Centrolene sp. nov. should be classified as Critically Endangered.

This unique glass frog seems to be restricted to the Central Coast Lowlands Evergreen Forest. In 1996, just 19.06% of the original area of this habitat was left, being the most endangered habitat in Ecuador. It is very fragmented, so the human pressure over the last remains of forest is very high, as witnessed in RPSC, which now is a banana plantation.

Characteristic features of Centrolene sp. nov.: A) humeral spine, B) prepollical spine, K) developed process on the 3rd metacarpalIMAGE 14
IMAGE15

The IUCN category and criteria that we use on this assessment are: CRITICALLY ENDANGERED: CR A2c+3ce; B2ab(ii,iii,iv)

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Significance

The Neotropical region and its amazing biodiversity is a world-wide treasure, and countries like Ecuador have been classified Megadiverse. However, much of this diversity is endangered by habitat loss due to unsustainable development, global climate change, diseases, illegal trade, environmental pollution, among others.

The current knowledge of Ecuadorian herpetofauna still does not let to develop an adequate conservation assessment for most populations of amphibians and reptiles in the country. Several glass frogs seem to be more or less endangered, for example the highland species Centrolene buckleyi has not been recorded since 1996. We urgently encourage conservation actions, prioritizing on endemic and key areas, as well as increase the support to the research of the amphibian and reptiles and the ecosystems in which they live.

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Acknowledgments

We are especially thankful to Ken Tighe, Ronald Heyer, Steve Gotte and George Zug for providing support and imparting knowledge to Diego F. Cisneros-Heredia (DFCH) on his work at the Division of Amphibians and Reptiles, NMNH, Smithsonian Institution. We appreciate the comments of William Duellman and John Lynch about our research. DFCH's work was done as an intern of the Research Training Program 2002 of the Smithsonian Institution, through a grant from the Smithsonian Women's Committee. DFCH would like to express his deepest gratitude to his advisor Roy McDiarmid for the time, patience, and knowledge that he gave him; as well as, to Maria Elena Heredia and Laura Heredia who provided love, support and financial assistance. We also thank Mary Sangrey, Nina Buttler and DFCH's partners of the RTP 2002 for helping in so many ways!

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ENTOMOLOGY

Sarah Garrett
"An Inventory of Leafroller Species of Moths of the Great Smoky Mountains National Park"

Abstract / Summary

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