''Anstisia vitellina'', commonly known as the orange-bellied 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 ...

in the family

Myobatrachidae Myobatrachidae, commonly known as Australian ground frogs or Australian water frogs, is a family of frogs found in Australia and New Guinea. Members of this family vary greatly in size, from species less than long, to the second-largest frog in ...

. It is endemic to a 20 hectare area near

Margaret River The Margaret River is a river in southwest Western Australia. In a small catchment, it is the eponym of the town and tourist region of Margaret River. The river arises from a catchment of just 40 square kilometres in the Whicher Range. The ...

Southwest Australia Southwest Australia is a biogeographic region in Western Australia. It includes the Mediterranean-climate area of southwestern Australia, which is home to a diverse and distinctive flora and fauna. The region is also known as the Southwest Aus ...

. It is vulnerable to extinction due to fire and the destruction of habitat caused by feral pigs.

Taxonomy

It was formerly classified in the genus ''

Geocrinia ''Geocrinia'' is a genus of frogs in the family Myobatrachidae. These frogs are endemic to Australia. Two species are known from southeastern Australia (Victoria and Tasmania), while one is known from southeastern Western Australia. All the spe ...

'', but was reclassified into the new genus ''

Anstisia ''Anstisia'' is a genus of frogs in the family Myobatrachidae. These frogs are endemic to southern Western Australia. Prior to 2022, these species were classified in the genus ''Geocrinia''. However, a study split four ''Geocrinia'' species into ...

'' in 2022.

Description

''G. vitellina'' is very similar in appearance to the white-bellied frog (''A. alba''); having spots of dark brown on a light brown or grey back, with has a

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 ...

of 17–24 mm." Cophixalus hosmeri (SVL = 17 mm) and Geocrinia vitelline (SVL = 18 mm), with mean clutch sizes of only 6 and 11 eggs, respectively." The underparts, however, are paler and vivid orange in the front.

Environment and ecology

The species occupies an area of 20 ha, the smallest of any

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

n mainland vertebrate, across a range of 6.3 km² around

Witchcliffe Witchcliffe is a small town in the South West (Western Australia), South West region of Western Australia, located a few kilometres south of Margaret River, Western Australia, Margaret River on the Bussell Highway. The name originates from a cav ...

. This narrow range is confined to swampy areas near

creek A creek in North America and elsewhere, such as Australia, is a stream that is usually smaller than a river. In the British Isles it is a small tidal inlet. Creek may also refer to: People * Creek people, also known as Muscogee, Native Americans ...

lines. Six creeks on the Blackwood River, Western Australia have been found to provide appropriate habitat. Populations are isolated due to breeding behaviour and a small individual range—unusual for frog species. A call is given in spring and early summer with a series of 9–15 pulses only just discernible. Eggs are laid in depressions, surrounded by a jelly mass. Without feeding or swimming, the tadpoles progress to an adult stage.

Threatened status

The small range of this species has made it vulnerable to threats such as fire and 'wild pigs', water pollution through agricultural runoff, and changes to the

hydrology Hydrology () is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and environmental watershed sustainability. A practitioner of hydrology is calle ...

of the riparian habitat through land-use.

References

* * {{Authority control Anstisia Amphibians of Western Australia Vulnerable fauna of Australia Amphibians described in 1989 Frogs of Australia Endemic fauna of Southwest Australia Warren bioregion