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Ansonia spinulifer

Ansonia spinulifer, also known as the spiny slender toad or Kina Balu stream toad, is a species of true toad native to the rainforests of northern Borneo. This toad is distinguished by its large, spinose warts, which give it its name, and its specialized breeding habits that occur near clear, rocky-bottomed streams.

Key Facts

  • Males measure 30–40 MM and females up to 45 MM in snout-to-vent length.
  • The dorsum features large, spinose warts, often with a light spot between the shoulders.
  • Found in lowland rainforests between 150–750 meters elevation.
  • Breeding requires small, clear, rocky-bottomed streams where tadpoles cling to rocks.
  • Males call at night from low vegetation near streams to attract females.
  • Threatened by habitat loss, deforestation, and stream siltation.
Ansonia spinulifer
Scientific Name
Ansonia spinulifer
Family
Bufonidae
Common Names

Spiny Slender Toad, Kina Balu Stream Toad

Description
Ansonia spinulifer is a species of true toad characterized by prominent, spinose warts on its dorsum, which are a key identifying feature. These warts possess keratinized projections, giving the toad a rough, spiky appearance. Males typically range from 30–40 mm in snout-to-vent length, while females can grow up to 45 mm. The tympanum is visible, and a light-colored spot is often observed between the shoulders. Its tadpoles possess a characteristic sucker mouth adapted for clinging to rocks in fast-flowing water.
Habitat Description
This toad is found in lowland rainforests at elevations ranging from 150 to 750 meters above sea level. Adults are wide-ranging, inhabiting the forest floor and herb stratum in areas with steep terrain. However, successful breeding is contingent upon the presence of small, clear, rocky-bottomed streams, which provide the necessary environment for their specialized tadpoles.
Breeding Behavior
During the breeding season, male Ansonia spinulifer call at night from low vegetation situated close to streams. These vocalizations are used to attract females. Reproduction is known to occur near streams, as indicated by the stream-dwelling nature of the tadpoles and the habits of related species. The tadpoles are adapted to torrents, clinging to rocks.
Vocalization
Males produce calls at night, typically from low vegetation adjacent to streams, to attract females for breeding.
Size Range Mm
30-45 mm
Habitat Type

Rainforest, Wetlands, Streams

Distribution States

Sarawak, Sabah, Kalimantan

Distinguishing Features

Large, Spinose Warts On the Dorsum, Keratinized Projections On Warts, Light Spot Between the Shoulders, Visible Tympanum

About Ansonia spinulifer

Ansonia spinulifer: The Spiny Stream Toad

Ansonia spinulifer, commonly known as the spiny slender toad or Kina Balu stream toad, is a species of true toad belonging to the Bufonidae family. This amphibian is native to the lush lowland rainforests of northern Borneo, with documented populations in Sarawak and Sabah (Malaysia), and presumed presence in Kalimantan (Indonesia).

Description and Habitat

The spiny slender toad is characterized by its distinctive appearance, featuring large, spinose warts on its dorsum that possess keratinized projections, which give the species its name. Males typically measure between 30 to 40 millimeters (1.2–1.6 inches) in snout-to-vent length, while females can reach up to 45 millimeters (1.8 inches). The tympanum is visible, and a notable light spot is often present between the shoulders. Its natural habitat consists of lowland rainforests at elevations ranging from 150 to 750 meters (490–2,460 ft) above sea level. Adults are found across the forest floor and herb stratum in areas with steep terrain.

Breeding and Life Cycle

Reproduction for Ansonia spinulifer is closely tied to its specific habitat requirements. Breeding necessitates the presence of small, clear, rocky-bottomed streams. During the breeding season, males actively call at night from low vegetation near these streams to attract females. The tadpoles of this species are adapted to torrent environments, possessing a typical sucker mouth that allows them to cling to rocks, where they feed on lithophytes. This specialized breeding behavior highlights the toad's dependence on undisturbed aquatic and riparian ecosystems.

Conservation Concerns

While Ansonia spinulifer is reported to be common in Sarawak, it demonstrates a limited ability to adapt to habitat modification. The primary threats to its survival are habitat loss, driven by deforestation and the subsequent siltation of streams. The expansion of plantations also contributes to the degradation of its specialized rainforest and stream habitats, posing a significant risk to the long-term viability of its populations.

Source: Wikipedia ↗

Frequently Asked Questions

What are the size ranges for Ansonia spinulifer?

Adult males typically measure between 30 to 40 millimeters (1.2 to 1.6 inches) in snout-to-vent length. Females are larger, reaching up to 45 millimeters (1.8 inches).

What does Ansonia spinulifer look like?

This toad is characterized by large spinose warts on its dorsum, which have keratinized projections. A distinctive light spot is often present between the shoulders. The tympanum is visible.

Where does Ansonia spinulifer live?

Its natural habitats are lowland rainforests in Sarawak and Sabah, northern Borneo (Malaysia), and it is presumed to also occur in Kalimantan, Indonesia. They inhabit areas with steep terrain.

How does Ansonia spinulifer reproduce?

Breeding requires small, clear, rocky-bottomed streams. Males call at night from low vegetation near these streams to attract females. The tadpoles are rheophilous, meaning they live in torrents and cling to rocks.

What are the threats to Ansonia spinulifer?

The species is threatened by habitat loss, primarily due to deforestation. Associated factors include the siltation of streams and the expansion of plantations, which negatively impact its specialized habitat requirements.