AmphibiaWeb - Didynamipus sjostedti


(Translations may not be accurate.)

Didynamipus sjostedti Andersson, 1903
Four-digit Toad
family: Bufonidae
genus: Didynamipus
Species Description: Andersson, L. G. (1903). Neue Batrachier aus Kamerun, von den Herren Dr. Y. Sjöstedt und Dr. R. Jungner gesammelt. Verhandlungen des Zoologisch-Botanischen Vereins in Wien 53: 141–145.

© 2006 Vaclav Gvozdik (1 of 2)
Conservation Status (definitions)
IUCN Red List Status Account Vulnerable (VU)
National Status None
Regional Status None



View distribution map in BerkeleyMapper.


Didynamipus sjostedti is a toad with a snout-vent length of 15 - 18 mm. The triangular head is broad, flat, and has a width of 4.8 - 5.8 mm. The snout length is 2.7 - 3.0 mm, which is as long as the eye diameter. The nostrils are below the canthus rostralis, and they are slightly closer to the snout tip than they are to the eye. The canthus rostralis is prominent. The interorbital space is much wider than the eyelid. The forearm is 4.0 - 4.3 mm. The finger formula is I < IV < II < III. The tibia is 6.8 - 7.8 mm, and is longer than the thigh, which is 6.2 - 7.0 mm. The foot length is 4.6 - 5.0 mm. The toe formula is I < II or V < III < IV. No subarticular protuberances are present, but the metatarsal tubercle is rounded. The tibiotarsal articulation reaches the eye. The skin is covered in fine granulations, and a triangular area below the vent is covered in flat warts (Andersson 1903).

The dorsum is yellowish brown with small, dark spots. The ventrum is whitish. There is a black stripe extending from the eye to the snout tip, below the canthus rostralis. It is unclear whether this is in life or preservative (Andersson 1903).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Cameroon, Equatorial Guinea, Nigeria


View distribution map in BerkeleyMapper.
The species distribution ranges from southwest Cameroon, Africa, across the border between Nigeria and the Republic of Cameroon, to Bioko Island, Equatorial Guinea (IUCN 2022). Cameroon has highly diverse herpetofauna, hosting over 3% of global species diversity. Didynamipus sjostedti inhabits moist forest clearings and forest edges in the lowlands and submontane regions of the Cameroon Volcanic Belt. Individuals have been found in leaf litter and on low-lying vegetation. Individuals have been seen in disturbed areas, such as one individual observed crossing a road in an area composed of secondary forest and farmland (Gonwouo et al. 2013).

Life History, Abundance, Activity, and Special Behaviors
Didynamipus sjostedti has often been found in groups of as many as 40 individuals consisting of both sexes at various life stages. Oviposition is suspected to be terrestrial and the species is likely direct-developing (Gonwouo et al. 2013).

The species is likely direct-developing (Gonwouo et al. 2013).

Trends and Threats
Didynamipus sjostedti was previously listed as endangered. Its current IUCN assessment status is "Vulnerable" due to suspected population declines caused by land conversion and agriculture (IUCN 2017).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
Drainage of habitat
Dams changing river flow and/or covering habitat
Local pesticides, fertilizers, and pollutants


The species is the only member of its genus, based on morphology (Grandison 1981).

The species epithet “sjostedti” is in honor of Bror Yngve Sjöstedt, a Swedish naturalist who collected the type specimen (Andersson 1903).

Didynamipus sjostedti was once considered the rarest bufonid in Africa. This was in part due to the lack of sampling in the region, and observations have since shown that the species has a larger range than initially believed (Gonwouo 2013).

Andersson, L. G. (1903). Neue Batrachier aus Kamerun, von den Herren Dr. Y. Sjöstedt und Dr. R. Jungner gesammelt. Verhandlungen des Zoologisch-Botanischen Vereins in Wien 53: 141–145.

Gonwouo, Ndeh, A., Tapondjou, W., & Noonan, B. (2013). Amphibia, Bufonidae, Didynamipus sjostedti Andersson, 1903: new records and a review of geographic distribution. Check List (9, Issue 4, 780–782). [link]

Grandison, A.G. (1981). Mophology and Phylogenetic Position of the West African Didynamipus Sjostedti Andersson, 1903 (Anura Bufonidae). Monitore Zoologico Italiano - Italian Journal of Zoology, 15, 187-215.

IUCN SSC Amphibian Specialist Group. 2017. Didynamipus sjostedti. The IUCN Red List of Threatened Species 2017: e.T54811A16272990. [link] Accessed on 18 April 2023.

Originally submitted by: Madeline Ahn (2023-04-26)
Description by: Madeline Ahn (updated 2023-04-26)
Distribution by: Madeline Ahn (updated 2023-04-26)
Life history by: Madeline Ahn (updated 2023-04-26)
Larva by: Madeline Ahn (updated 2023-04-26)
Trends and threats by: Madeline Ahn (updated 2023-04-26)
Comments by: Madeline Ahn (updated 2023-04-26)

Edited by: Ann T. Chang (2023-04-26)

Species Account Citation: AmphibiaWeb 2023 Didynamipus sjostedti: Four-digit Toad <> University of California, Berkeley, CA, USA. Accessed Feb 29, 2024.

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Citation: AmphibiaWeb. 2024. <> University of California, Berkeley, CA, USA. Accessed 29 Feb 2024.

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