genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
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
Eleutherodactylidae
The Eleutherodactylidae are a family of direct-developing frogs native to northern South America, the Caribbean, and southernmost North America. They are sometimes known under the common name rain frogs. Formerly the subfamily Eleutherodactylina ...
.Hedges, S. B., W. E. Duellman, and M. P. Heinicke . 2008. New World direct-developing frogs (Anura: Terrarana): molecular phylogeny, classification, biogeography, and conservation. Zootaxa 1737: 1-182. Many of the 200 species of the genus are commonly known as "rain frogs" or "robber frogs", due to their sharp, high-pitched, insect-like calls.
The best-known species is the common coquí (''E. coqui''), which is both a national symbol of
Puerto Rico
Puerto Rico (; abbreviated PR; tnq, Boriken, ''Borinquen''), officially the Commonwealth of Puerto Rico ( es, link=yes, Estado Libre Asociado de Puerto Rico, lit=Free Associated State of Puerto Rico), is a Caribbean island and Unincorporated ...
and a notorious
invasive species
An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...
in
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...
. Two ''Eleutherodactylus'' species, '' E. limbatus'' and '' E. iberia'', are among the smallest known frogs, measuring only 8.5 mm in length (only slightly larger than ''
Paedophryne amauensis
''Paedophryne amauensis'' is a species of microhylid frog endemic to eastern Papua New Guinea. At in snout-to-vent length, it is considered the world's smallest known vertebrate. (See also Ecological guild.)
The species was listed in the '' ...
'', which measures around 7.7 mm).
Etymology
The name "Eleutherodactylus" is derived from the
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
words for ‘free-toed’, composed of the Ancient Greek ' (, ‘free, unbound’) and ' (, ‘finger, toe’).
Most species are small, slender, and cryptically colored, with three to five free toes. A few, such as the
web-footed coquí
The web-footed coqui, stream coqui, Puerto Rican stream frog or Karl's robber frog (''Eleutherodactylus karlschmidti''), is a possibly extinct Puerto Rican frog species in the family Eleutherodactylidae. It was first described by Chapman Grant ...
(''E. karlschmidti'') of Puerto Rico, do have completely webbed feet.
Distribution and habitat
Species of ''Eleutherodactylus'' are found throughout the Neotropics, including the southern United States, Mexico, Central America, and the Caribbean. Additionally, the common coquí (''E. coqui'') has been introduced to several islands in the
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...
an archipelago, as well as elsewhere in the Pacific.
They can be terrestrial, arboreal, or aquatic, typically living in forests or
riparian
A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks ar ...
areas, and feeding primarily upon
arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...
s. Many ''Eleutherodactylus'' species have highly restricted ranges and are found on only one island or in one or a few localities. Even some of these restricted species can occur at very high densities.
Reproduction and development
All species of ''Eleutherodactylus'' are characterized by direct development, in which eggs hatch directly into small frogs, completely bypassing the
tadpole
A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found i ...
stage. This adaptation may be largely responsible for their ecological and evolutionary success. Most species are characterized by parental behaviors, such as egg-guarding by either the male or female parent. In some cases, even young froglets are attended by parents. Another extinct Puerto Rican species, the golden coquí (''E. jasperi''), gave birth to live young. Many species (for example, Cook's robber frog, ''E. cooki''), also of Puerto Rico, exhibit
sexual dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...
in size and color.
Study on ''Eleutherodactylus'' and ''
Lithobates
''Lithobates'' is a genus of true frogs, of the family Ranidae. The name is derived from '' litho-'' (stone) and the Greek ' (, one that treads), meaning one that treads on rock, or rock climber.
The name was defined by Hillis and Wilcox (2005) ...
'' amphibians shows that number of offsprings instead of body size may help to find which species require conservation from being extinct.
Phylogenetics
The basis of forming this genus has been morphological, but sequence comparisons of
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
mitochondrial
A mitochondrion (; ) is an organelle found in the cells of most Eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is use ...
DNA, and
ribosomal
Ribosomes ( ) are macromolecular machines, found within all cells, that perform biological protein synthesis (mRNA translation). Ribosomes link amino acids together in the order specified by the codons of messenger RNA (mRNA) molecules to fo ...
RNA
Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...
have shown geographic range is a much more consistent predictor of
cladistics
Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived char ...
for this group of frogs. The climbing habits of many species have
evolved independently
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...
. All true members of the genus have been clustered into
subgenera
In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus.
In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between t ...
, but many less-related species require more genetic data before they are to be officially classified elsewhere. The theory that the eleutherodactyline colonization of
Central America
Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...
and the
Caribbean
The Caribbean (, ) ( es, El Caribe; french: la Caraïbe; ht, Karayib; nl, De Caraïben) is a region of the Americas that consists of the Caribbean Sea, its islands (some surrounded by the Caribbean Sea and some bordering both the Caribbean Se ...
from their origins in South America occurred during the
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
has fallen out of favor. The
fossil record
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...
, combined with
molecular clock
The molecular clock is a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged. The biomolecular data used for such calculations are usually nucleoti ...
analyses, indicate the subgenera were probably founded by small groups of individuals by
flotsam
In maritime law, flotsam'','' jetsam'','' lagan'','' and derelict are specific kinds of shipwreck. The words have specific nautical meanings, with legal consequences in the law of admiralty and marine salvage. A shipwreck is defined as the rema ...
dispersal during the
Eocene
The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...
or
Oligocene
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...
epochs.
Land bridge
In biogeography, a land bridge is an isthmus or wider land connection between otherwise separate areas, over which animals and plants are able to cross and Colonisation (biology), colonize new lands. A land bridge can be created by marine regre ...
s would have been limited to facilitating dispersal between
West Indian
A West Indian is a native or inhabitant of the West Indies (the Antilles and the Lucayan Archipelago). For more than 100 years the words ''West Indian'' specifically described natives of the West Indies, but by 1661 Europeans had begun to use it ...
islands, however, the Oligocene division of
Hispaniola
Hispaniola (, also ; es, La Española; Latin and french: Hispaniola; ht, Ispayola; tnq, Ayiti or Quisqueya) is an island in the Caribbean that is part of the Greater Antilles. Hispaniola is the most populous island in the West Indies, and th ...
and
Cuba
Cuba ( , ), officially the Republic of Cuba ( es, República de Cuba, links=no ), is an island country comprising the island of Cuba, as well as Isla de la Juventud and several minor archipelagos. Cuba is located where the northern Caribbea ...
resulted in further speciation. The distribution of the subgenus '' Syrrhopus'' is most likely due to a secondary dispersal to Central America from the
Greater Antilles
The Greater Antilles ( es, Grandes Antillas or Antillas Mayores; french: Grandes Antilles; ht, Gwo Zantiy; jam, Grieta hAntiliiz) is a grouping of the larger islands in the Caribbean Sea, including Cuba, Hispaniola, Puerto Rico, Jamaica, and ...
during the
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...
. The formation of the
Panama Isthmus
The Isthmus of Panama ( es, Istmo de Panamá), also historically known as the Isthmus of Darien (), is the narrow strip of land that lies between the Caribbean Sea and the Pacific Ocean, linking North and South America. It contains the country ...
during the
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58 ''
Sensu stricto
''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular co ...
'', however, it should exclude clades with distributions south of the
Panama Canal
The Panama Canal ( es, Canal de Panamá, link=no) is an artificial waterway in Panama that connects the Atlantic Ocean with the Pacific Ocean and divides North and South America. The canal cuts across the Isthmus of Panama and is a conduit ...
.
Fossil record
Frog remains referred to ''Eleutherodactylus'' have been reported from
Dominican amber
Dominican amber is amber from the Dominican Republic derived from resin of the extinct tree '' Hymenaea protera''.
Dominican amber differentiates itself from Baltic amber by being nearly always transparent, and it has a higher number of fossil inc ...
.
Species
The following species are recognised in the genus ''Eleutherodactylus'':
* '' Eleutherodactylus aporostegus'' Schwartz, 1965
* ''
Eleutherodactylus bothroboans
''Eleutherodactylus'' is a genus of frogs in the family Eleutherodactylidae.Hedges, S. B., W. E. Duellman, and M. P. Heinicke . 2008. New World direct-developing frogs (Anura: Terrarana): molecular phylogeny, classification, biogeography, and co ...
'' Schwartz, 1965
* ''
Eleutherodactylus campi
''Eleutherodactylus cystignathoides'', also known as the Rio Grande chirping frog, Mexican chirping frog, or lowland chirping frog, is a small Eleutherodactylidae, eleutherodactylid frog. It is found from the southern United States in Texas, and ...
Eleutherodactylus feichtingeri
''Eleutherodactylus'' is a genus of frogs in the family Eleutherodactylidae.Hedges, S. B., W. E. Duellman, and M. P. Heinicke . 2008. New World direct-developing frogs (Anura: Terrarana): molecular phylogeny, classification, biogeography, and co ...
Eleutherodactylus melatrigonum
''Eleutherodactylus'' is a genus of frogs in the family Eleutherodactylidae.Hedges, S. B., W. E. Duellman, and M. P. Heinicke . 2008. New World direct-developing frogs (Anura: Terrarana): molecular phylogeny, classification, biogeography, and co ...
'' Schwartz, 1966
* ''
Eleutherodactylus notidodes
South Island telegraph frog (''Eleutherodactylus audanti'') is a species of frog in the family Eleutherodactylidae Endemism, endemic to Cuba. It occurs in the Massif de la Hotte and Massif de la Selle, Cuba, and in the Sierra de Baoruco, the Domi ...
Eleutherodactylus rucillensis
''Eleutherodactylus'' is a genus of frogs in the family Eleutherodactylidae.Hedges, S. B., W. E. Duellman, and M. P. Heinicke . 2008. New World direct-developing frogs (Anura: Terrarana): molecular phylogeny, classification, biogeography, and co ...
West Indian
A West Indian is a native or inhabitant of the West Indies (the Antilles and the Lucayan Archipelago). For more than 100 years the words ''West Indian'' specifically described natives of the West Indies, but by 1661 Europeans had begun to use it ...
(subgenus ''
Eleutherodactylus
''Eleutherodactylus'' is a genus of frogs in the family Eleutherodactylidae.Hedges, S. B., W. E. Duellman, and M. P. Heinicke . 2008. New World direct-developing frogs (Anura: Terrarana): molecular phylogeny, classification, biogeography, and c ...
West Indian
A West Indian is a native or inhabitant of the West Indies (the Antilles and the Lucayan Archipelago). For more than 100 years the words ''West Indian'' specifically described natives of the West Indies, but by 1661 Europeans had begun to use it ...
Hispaniola
Hispaniola (, also ; es, La Española; Latin and french: Hispaniola; ht, Ispayola; tnq, Ayiti or Quisqueya) is an island in the Caribbean that is part of the Greater Antilles. Hispaniola is the most populous island in the West Indies, and th ...
North
North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating Direction (geometry), direction or geography.
Etymology
T ...
/
Central America
Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...
n and
Cuba
Cuba ( , ), officially the Republic of Cuba ( es, República de Cuba, links=no ), is an island country comprising the island of Cuba, as well as Isla de la Juventud and several minor archipelagos. Cuba is located where the northern Caribbea ...