''Alcalus'' is a small genus of frogs in the family

Ceratobatrachidae The Ceratobatrachidae are a family of frogs found in the Malay Peninsula, Borneo, the Philippines, Palau, Fiji, New Guinea, and the Admiralty, Bismarck, and Solomon Islands. Taxonomy Ceratobatrachidae was formerly treated as a subfamily (i.e ...

. It is the only member of the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

Alcalinae. 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 ...

is Ceratobatrachinae. Common name Alcala's dwarf mountain frogs has been proposed for the genus. They are found in

Palawan Island Palawan is the largest island of the province of Palawan in the Philippines and fifth-largest by area and tenth-most populous island of the country, with a total population of 994,101 as of 2020 census. The north west coast of the island is alon ...

(the Philippines),

Borneo Borneo (; id, Kalimantan) is the third-largest island in the world and the largest in Asia. At the geographic centre of Maritime Southeast Asia, in relation to major Indonesian islands, it is located north of Java, west of Sulawesi, and eas ...

, and the

Malay Peninsula The Malay Peninsula (Malay: ''Semenanjung Tanah Melayu'') is a peninsula in Mainland Southeast Asia. The landmass runs approximately north–south, and at its terminus, it is the southernmost point of the Asian continental mainland. The area ...

. They prefer semi-aquatic microhabitats.

Etymology

The genus is named in honour of

Angel Alcala Angel Chua Alcala, , (born March 1, 1929) is a Filipino biologist who was named a National Scientist of the Philippines in 2014. Alcala is known for his fieldwork to build sanctuaries and to promote biodiversity in the aquatic ecosystems of the P ...

, a Filipino biologist who has worked with Southeast Asian amphibians.

Description

Compared to the closely related genera ''

Cornufer ''Cornufer'' is a genus of frogs in the family Ceratobatrachidae. It has been greatly expanded by Brown, et al. (2015) to include most Australasian frogs in the family Ceratobatrachidae. Species are found in Melanesia and Polynesia Polynesi ...

'' and ''

Platymantis ''Platymantis'' is a genus of frogs in the family Ceratobatrachidae. They are commonly known as wrinkled ground frogs, ground frogs, and forest frogs. As currently defined, ''Platymantis'' is a large genus with up to as many as 60 species foun ...

'', ''Alcalus'' have an intermediate body size (based on '' Alcalus baluensis'' and '' A. mariae'', males measure and females in snout–vent length). The head is broad. Skin is coarsely textured, shagreened, or ‘wrinkled’ in appearance. The toe discs are widely expanded; inter-digital webbing is extensive. Males have nuptial pads but lack

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 o ...

Species

There are five species: * '' Alcalus baluensis'' (Boulenger, 1896) * '' Alcalus mariae'' (Inger, 1954) * '' Alcalus rajae'' (Iskandar, Bickford, and Arifin, 2011) * '' Alcalus sariba'' (Shelford, 1905) * '' Alcalus tasanae'' (Smith, 1921)

References

{{Taxonbar, from=Q19901049 Ceratobatrachidae Amphibian genera Amphibians of Asia Taxa named by Rafe M. Brown Taxa named by David C. Cannatella Taxa named by Arvin Cantor Diesmos Taxa named by Stephen J. Richards