Rana lenca: A new species of Leopard Frog from the central Honduran highlands.

Leopard Frogs, Rana spp., are found throughout North and Central America, where they are common in most damp environments. Despite their ubiquity, their taxonomy is not as well understood as might be expected, with new species being described regularly not just from the tropical regions of Central America, but from densely populated areas of North America (a new species was described from New York City in 2014).

In a paper published in the journal Systematics and Biodiversity on 4 January 2018, Ileana Luque-Montes of the Department of Wildlife Ecology and Conservation at the University of Florida, and the Department of Biology at the Indiana University of Pennsylvania, James Austin, also of the Department of Wildlife Ecology and Conservation at the University of Florida, Kayla Weinfurther, also of the Department of Biology at the Indiana University of Pennsylvania, Larry David Wilson of the Centro Zamorano de Biodiversidad at the Escuela Agrícola Panamericana Zamorano, and Erich Hofmann and Josiah Townsend, again of the Department of Biology at the Indiana University of Pennsylvania, describe a new species of Leopard Frog from the Chortís Highlands of central Honduras.

The majority of Leopard Frogs in Honduras have long been considered to belong to two species, Rana brownorum, which is found in river basins draining north into the Caribbean, and Rana forreri found in river basins draining south into the Pacific. There are also known to be morphologically distinct Leopard Frogs in the Chortís Highlands of central Honduras, that separate the two drainage zones. These have long been considered to be hybrids of the two lowland populations, found along the zone that separates the species. However, this does not fit well with our current understanding of species boundaries in Frogs and Amphibians, which suggests two lowland species are unlikely to hybridise to form produce a highland species, rather species are typically restricted to (often quite narrow) altitude bands, and topology often delineating the boundaries between populations of different species.

Luque-Montes et al. sampled the DNA of Leopard Frogs from across Honduras, and used these to establish that the Frogs of the Chortís Highlands are in fact a separate species. This species is named Rana lenca, in honour of the Lenca people of southwest Honduras. This species is slightly smaller than Rana brownorum and Rana forreri, with adult males reaching 46.6–64.3 mm, and females 43.7–76.3 mm, but have relatively larger heads than either of these species. They are greenish in colour, with well-defined dorsal spots and a paler underside. 

Rana lenca, adult female from the Reserva Biologica Cerro Uyuca. Josiah Townsend in Luque-Montes et al. (2018).

See also...

Follow Sciency Thoughts on Facebook.

A new species of Leopard Frog from New York City.

Cryptic species are species that closely resemble other species, and cannot be separated by simple, non-invasive examination. While taxonomists have known about cryptic species for a long time, it was not realised how numerous such species were until taxonomists began to use genetics to determine relationships between species, about twenty years ago. The presence of cryptic species can have a profound influence on conservation efforts, as ‘species’ thought to be wide ranging with large populations and broad environmental tolerances can turn out to be complexes of closely related but reproductively isolated species, each with a smaller population and distribution, and narrower range of environmental tolerances.

In a paper published in the journal PLoS One on 29 October 2014, a team of scientists led by Jeremy Feinberg of the Department of Ecology, Evolution,and Natural Resources at Rutgers University describe a new, cryptic, species of Leopard Frog from New York City and the surrounding areas of the American East Coast.

The new species is named Rana kauffeldi, after the herpetologist Carl Kauffeld, who studied Leopard Frogs in the eastern United States in the 1930s, and concluded that there might be an undescribed species in the New York/New Jersey area. Fienberg et al. recommend that it be given the common English name ‘Atlantic Coast Leopard Frog’

Rana kauffeldiwas first identified on Staten Island, where it was noticed due to its distinctive call, which differs from that of the two other Leopard Frogs found in the northeastern United States, the Northern Leopard Frog, Rana pipiens, and the Southern Leopard Frog, Rana sphenocephala, by its call (Rana pipiens and Rana sphenocephala are themselves cryptic, and can only be readily separated by their calls, though these two species have long been known to science). It was subsequently confirmed as a separate species by genetic analysis, and subsequently found to be distributed in coastal areas from Connecticut to North Carolina. The species favours coastal freshwater wetlands, including tidally influenced waterways, marshes and wet meadows.

Rana kauffeldi, male specimen in dorsolateral view. Fienberg et al. (2014).

Rana kauffeldi is only the second species of Frog discovered in North America north of Mexico since 1986. It is also the first new species of Frog discovered in New England since 1882, and only the seventh species of Amphibian ever discovered in New York State. Its presence in one of the world’s largest and most densely populated metropolises is therefore somewhat of a surprise, particularly as it is a fairly large and conspicuous species. While the detection of new Frog species by genetic data is new, the detection of such species by their calls is a long established procedure; for example the Gray Treefrogs Hyla versicolor and Hyla chrysoscelis, small, tree-dwelling and inconspicuous species from the eastern United States, have been recognised as separate species for over 60 years.

See also…

A new cryptic species of Microhylid Frog from Espírito Santo State, Brazil.

Cryptic species are species which resemble one-another physically, and which cannot generally be separated using traditional taxonomic methodology, but which are nevertheless genetically and reproductively isolated. Genetic studies of many groups of...

Four new species of Treefrog from South America.

Many species of Amazonian Amphibians are considered to be highly threatened due to habitat loss, with the potential for the situation to become much worse due to climate change in the near future. This has led to increased efforts to understand the ecology and...

Frogs and Toads from the Early Eocene of Gujarat State, India.

The Cambay Shale formation from the Vastan Lignite Mine to the northeast of Surat in Gujarat State, India, has produced a diverse and significant Vertebrate...

Follow Sciency Thoughts on Facebook.