''Hyperolius thomensis'' 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 ...

in the family

Hyperoliidae The Hyperoliidae, or sedge frogs and bush frogs, are a large family of small to medium-sized, brightly colored frogs which contains more than 250 species in 19 genera. Seventeen genera are native to sub-Saharan Africa. In addition, the monotypic ...

. 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 island of São Tomé in

São Tomé and Príncipe São Tomé and Príncipe (; pt, São Tomé e Príncipe (); English: " Saint Thomas and Prince"), officially the Democratic Republic of São Tomé and Príncipe ( pt, República Democrática de São Tomé e Príncipe), is a Portuguese-speaking i ...

. Common names São Tomé reed frog, São Tomé giant reed frog, and Sao Tome giant treefrog have been coined for it. It is the largest ''

Hyperolius ''Hyperolius'' (commonly known as the African reed frogs or reed frogs) is a large genus of frogs in the family Hyperoliidae from Sub-Saharan Africa Sub-Saharan Africa is, geographically, the area and regions of the continent of Africa th ...

'' species.

Taxonomy and systematics

The species was named by

José Vicente Barbosa du Bocage José Vicente Barbosa du Bocage (2 May 1823 – 3 November 1907) was a Portuguese zoologist and politician. He was the curator of Zoology at the Museu Nacional de Lisboa in Lisbon. He published numerous works on mammals, birds, and fishes. In t ...

in 1886. It is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

of the genus ''Nesionixalus'' Perret, 1976. Its

sister taxon 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 ...

Hyperolius molleri ''Hyperolius molleri'' is a species of frog in the family Hyperoliidae. It is Endemism, endemic to São Tomé Island. Records from Príncipe now refer to ''Hyperolius drewesi'', species description, described as a distinct species in 2016. Taxon ...

'' has also been placed in ''Nesionixalus''. Together, these two species form a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

, but its recognition as a genus would render rest of ''Hyperolius''

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

. The two species can form hybrids.

Description

Adult males measure and adult females in

snout–vent length Snout–vent length (SVL) is a morphometric measurement taken in herpetology from the tip of the snout to the most posterior opening of the cloacal slit (vent)."direct line distance from tip of snout to posterior margin of vent" It is the most c ...

. The dorsum is uniform brown or green to blue-green. The venter is marbled in white, orange and black. The ventral surfaces of the limbs are richly marbled in orange and black. Males have their dorsum densely beset with small spines. The pupil is horizontal.

Habitat and conservation

''Hyperolius thomensis'' inhabits primary rainforest remnants usually at altitudes above , but occasionally as low as . Breeding takes place in tree holes where their

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 ...

s develop, and the same hole can be utilized by many individuals. The threats to this species are poorly known, but it is probably impacted 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 ...

caused by agriculture, livestock, wood extraction, and human settlements. Its range includes the

Parque Natural Obô de São Tomé The Obô Natural Park of São Tomé ( pt, Parque Natural Obô de São Tomé) is a natural park of São Tomé and Príncipe, covering of the island of São Tomé Island, São Tomé. It was established in 2006, but yet to be assigned an IUCN protec ...

Threats

Habitat Loss

Habitat loss, primarily driven by the conversion of land for agriculture and livestock, poses a significant threat to the São Tomé Giant Reed Frog. Additionally, the species faces challenges from habitat reduction due to activities such as wood extraction and the expansion of human settlements.

Amphibian Chytrid Fungus (Bd) Infection

A survey conducted for the presence of the amphibian chytrid fungus (Bd) revealed infections dating back to 2001. Despite the identification of the fungus, no instances of sick or deceased frogs have been reported in the field. However, the highly virulent strain of the pathogen (Bd-GPL) present on São Tomé Island raises concerns about its potential threat to the species.