''Minervarya charlesdarwini'' (vernacular name: Charles Darwin's frog) is a species of

frog A frog is any member of a diverse and largely Carnivore, carnivorous group of short-bodied, tailless amphibians composing the order (biology), order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-f ...

s in the family

Dicroglossidae The frog family Dicroglossidae occurs in tropical and subtropical regions of Asia and Africa, with most genera and species being found in Asia. The common name of the family is fork-tongued frogs. The Dicroglossidae were previously considered to ...

. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the

Andaman Islands The Andaman Islands () are an archipelago in the northeastern Indian Ocean about southwest off the coasts of Myanmar's Ayeyarwady Region. Together with the Nicobar Islands to their south, the Andamans serve as a maritime boundary between th ...

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

, and is known from the

South Andaman Island South Andaman Island is the southernmost island of the Great Andaman and is home to the majority of the population of the Andaman Islands. It belongs to the South Andaman administrative district, part of the Indian union territory of Andaman an ...

Long Island Long Island is a densely populated island in the southeastern region of the U.S. state of New York (state), New York, part of the New York metropolitan area. With over 8 million people, Long Island is the most populous island in the United Sta ...

, and

North Andaman Island North Andaman Island is the northern island of Great Andaman of the Andaman Islands. It belongs to the North and Middle Andaman district, North and Middle Andaman administrative Districts of India, district, part of the Indian union territory o ...

Taxonomy

''Minervarya charlesdarwini'' was described in 1998 as ''Rana charlesdarwini'' by , but was moved to the genus ''Ingerana'' in 2006. However, this taxonomic placement was always considered uncertain. In 2022, a phylogenetic study found it to be a

sister species In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

to the Andaman frog (''M. andamanensis''), another endemic frog of the Andamans, and it was thus reclassified into the genus '' Minervarya''. Following the description of this species, specimens labelled as ''Rana doriae andamanensis'' collected by

Nelson Annandale Thomas Nelson Annandale CIE FRSE (15 June 1876, in Edinburgh – 10 April 1924, in Calcutta) was a British zoologist, entomologist, anthropologist, and herpetologist. He was the founding director of the Zoological Survey of India. Life The el ...

were found from the

Zoological Survey of India The Zoological Survey of India (ZSI), founded on 1 July 1916 by Government of India Ministry of Environment, Forest and Climate Change, as premier Indian organisation in zoological research and studies to promote the survey, exploration and r ...

. However, Annandale never formally described a taxon using that name, so it is an

unavailable name In zoological nomenclature, an unavailable name is a name that does not conform to the rules of the International Code of Zoological Nomenclature and that therefore is not available for use as a valid name for a taxon. Such a name does not fulfil th ...

Description

Adult males measure and adult females in snout–vent length. The snout is rounded and has a blunt tip. The tympanum is distinct and exposed; the supra-tympanic fold is well-developed and forms a thick, fleshy ridge. The fingers have no webbing whereas the toes are partially webbed. The finger and toe tips bear swollen discs, without circum-marginal grooves. Skin has minute granules scattered all over the dorsum; the venter is smooth. Colouration is variable with three different morphs: * The first morph is dull olive brown but has a bright orange butterfly-like marking on the dorsum behind the

occiput The occipital bone () is a cranial dermal bone and the main bone of the occiput (back and lower part of the skull). It is trapezoidal in shape and curved on itself like a shallow dish. The occipital bone overlies the occipital lobes of the cereb ...

, and a smaller spot of the same colour above the

sacral Sacral may refer to: *Sacred Sacred describes something that is dedicated or set apart for the service or worship of a deity; is considered worthy of spiritual respect or devotion; or inspires awe or reverence among believers. The property ...

region. Only very feeble black subocular spots are present, and the limbs lack barred pattern. * The second type is light tan and has very distinct black bars on the limbs. The dorsum has only a feeble W-like marking on the mid-dorsum and two indistinct orange spots. A mid-dorsal stripe might be present. Under moist conditions, the colour turns dark brown. Males have a dark

gular Gular is of or pertaining to the throat In vertebrate anatomy, the throat is the front part of the neck, internally positioned in front of the vertebrae. It contains the pharynx and larynx. An important section of it is the epiglottis, separatin ...

vocal sac The vocal sac is the flexible membrane of skin possessed by most male frogs and toads. The purpose of the vocal sac is usually as an amplification of their mating or advertisement call. The presence or development of the vocal sac is one way ...

. * The third morph, which is similar to the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

, is bright creamy white but with a dark brown patch on the dorsum as well as very thin, creamy white mid-dorsal stripe and two distinct, white subocular spots. Again, males have a dark gular vocal sac.

Habitat and conservation

''Minervarya charlesdarwini'' have been found in primary evergreen and secondary forests at elevations below . The eggs are laid in water-filled tree holes. It is threatened by

habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

(clear-cutting). The

type series In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes t ...

was collected in the

Mount Harriet National Park Mount Harriet National Park, officially renamed as Mount Manipur National Park, is a national park located in the Andaman and Nicobar Islands union territory of India. The park, established in 1969, covers about 4.62 km2 (18.00 mi2). ...

, and the species is also known from the

Saddle Peak National Park Saddle Peak National Park is a national park in the Andaman and Nicobar Islands in India. It was set up in 1979 on surrounding areas of Saddle Peak. Climate It covers an area of . The climate here is typically oceanic. Temperature usually varie ...

References

{{Taxonbar, from=Q1594589 charlesdarwini Frogs of India Endemic fauna of the Andaman Islands Amphibians described in 1998 Taxonomy articles created by Polbot