''Glandirana susurra'' 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 Ranidae, the "true frogs". 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 ...

Sado Island is a city located on in Niigata Prefecture, Japan. Since 2004, the city has comprised the entire island, although not all of its total area is urbanized. Sado is the sixth largest island of Japan in area following the four main islands and Ok ...

, Japan. It is the only endemic amphibian of the island. It is genetically close to the widespread '' Glandirana rugosa'', but it is morphologically distinguishable and postzygotically isolated from the latter species.

Etymology

The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

''susurra'' is derived from the Latin ''susurrus'' meaning "whispering" and refers to the relatively quiet advertisement call of this species compared to those of other sympatric anuran ('' Hyla japonica'' and '' Rhacophorus arboreus'').

Evolution

Both ''Glandirana rugosa'' and ''Glandirana susurra'' are present on Sado Island, but their ranges do not overlap: ''G. susurra'' occurs on the central part of the island while ''G. rugosa'' in the south and in the north. Together with the fact that the race of ''G. rugosa'' on Sida Island is only distantly related to ''G. susurra'', this suggests that ''G. susurra'' speciated on Sato Island before the invasion of the present ''G. rugosa'' lineage. Experiments suggest that the postzygotic reproductive isolation between these lineages is nearly perfect, although it remains to be confirmed that this also applies to specimens originating from areas near the species boundary.

Description

Adult males measure and adult females in snout–vent length. The snout is rounded. The tympanum is distinct and the supratympanic fold is well-developed. The fingers and the toes are slender with slightly depressed tips; no webbing is present between the fingers while the toes have well-developed webbing. Dorsal skin has many dermal ridges of varying size. The dorsum is khaki-colored, whereas the abdomen is almost whitish anteriorly and yellow posteriorly. A mid-dorsal stripe is present in some individuals. Males 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 ...

(present in ''G. rugosa'').

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 of

stages Stage or stages may refer to: Acting * Stage (theatre), a space for the performance of theatrical productions * Theatre, a branch of the performing arts, often referred to as "the stage" * ''The Stage'', a weekly British theatre newspaper * S ...

41–42 measure about in body length.

Habitat and conservation

''Glandirana susurra'' occurs near various bodies of water, such as rice fields, small streams, and ponds. It is known from elevations between

above sea level Height above mean sea level is a measure of the vertical distance (height, elevation or altitude) of a location in reference to a historic mean sea level taken as a vertical datum. In geodesy, it is formalized as ''orthometric heights''. The comb ...

. Spawning occurs in ponds from middle May to early August. Adult frogs and at least some tadpoles spend their winter in the mud under water. As of late 2019, this species has not been included in the

IUCN Red List of Threatened Species The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biologi ...

References

{{Taxonbar, from=Q3108497 susurra Frogs of Asia Amphibians of Japan Endemic fauna of Japan Amphibians described in 1979