Description

DESCRIPTION:

DIAGNOSIS: (How this species is differentiated from similar species)

COLORATION: (In life and/or in preservative)

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).

VARIATION: (if known)

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).

Larva
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
Urbanization
Drainage of habitat
Dams changing river flow and/or covering habitat
Local pesticides, fertilizers, and pollutants

Comments

PHYLOGENETIC RELATIONSHIPS:

ETYMOLOGY (Origin or explanation of scientific name):

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

OTHER INTERESTING INFORMATION:

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).

References
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.

Species Account Citation: AmphibiaWeb 2023 Didynamipus sjostedti: Four-digit Toad <https://amphibiaweb.org/species/332> University of California, Berkeley, CA, USA. Accessed May 14, 2025.

Citation: AmphibiaWeb. 2025. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 14 May 2025.

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