Pelomedusa subrufa (Bonnaterre, 1789)

Common Names and Species Classification

This turtle species, Pelomedusa subrufa, is commonly known as the marsh terrapin or African helmeted turtle.

Carapace Size

Most individuals have a straight carapace length between 15 cm and 21 cm, with nearly all measuring less than 20 cm; one individual has been recorded at 32.5 cm.

Carapace Color

Its carapace is black or brown.

Limb, Tail, and Plastron Color

The tops of its tail and feet are grayish brown, and its plastron (underside of the shell) is yellowish.

Sexual Dimorphism

Males can be distinguished by their long, thick tails, while females have shorter tails and broader carapaces.

Hatchling Characteristics

Hatchlings have shells roughly 3 cm long, and are olive to black in color.

Distinctive Gland and Tubercle Traits

This species has two small tubercles under the chin, and musk glands on the sides of the carapace.

Genus-Specific Plastron Trait

As a member of the genus Pelomedusa, this species lacks a hinged plastron, a trait unique to the genus within the family Pelomedusidae.

Pelomedusidae Plastron Comparison

All other Pelomedusidae species have a hinged plastron that can be closed against the carapace using muscles to cover the head and front limbs.

Righting Ability

Unlike many other chelonians, African helmeted turtles can right themselves if flipped upside down using a vigorous flick of their long muscular neck.

Genus Taxonomy Revision

Recent genetic research indicates the genus Pelomedusa contains at least 10 distinct species, rather than the single species previously recognized; historically, physical differences between populations were not considered large enough to separate them into multiple species.

African Geographic Range

The geographic range of Pelomedusa subrufa covers a large portion of Africa, extending from Cape Town in the south to Sudan in the north and Ghana in the west.

Extra-African Range Records

It has also been recorded in Madagascar and Yemen.

General Habitat Type

Pelomedusa subrufa is a semiaquatic species that lives in rivers, lakes, and marshes, and also occupies rain pools and fertilized areas.

Preferred Habitat

It prefers standing water habitats including swamps, pans, dams, and lakes, and occurs less commonly along rivers.

Absent Habitats

It is generally absent from mountainous, forested, and desert regions.

Courtship Timing

Courtship occurs year round for Pelomedusa subrufa.

Male Courtship Behavior

Males follow females and nod their heads in front of the females' heads.

Unresponsive Female Behavior

Unresponsive females will nip, snap, and leave.

Receptive Female Behavior

Receptive females respond by nodding their heads or remaining still, allowing the male to mount.

Mating Behavior

Both turtles shake their heads during mating.

Clutch Size and Laying Period

Females lay an average of two to ten eggs, usually in late spring and early summer.

Nest Characteristics

They deposit eggs in a flask-shaped nest that is 10 to 18 cm (4 to 7 in) deep.

Egg Incubation Period

Eggs hatch between 75 and 90 days after being laid.