Ranacephala hogei (Hoge’s side-necked turtle)

Ranacephala hogei, also known as Hoge’s side-necked turtle, is a rare freshwater species native to Brazil. This turtle belongs to the Chelidae family and is distinguished by its habit of tucking its head sideways rather than retracting it fully into the shell. Due to habitat destruction and other threats, it is considered one of the most endangered turtles in South America.

Scientific Classification

Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Testudines
Family: Chelidae
Genus: Ranacephala
Species: R. hogei

Common Names

Hoge’s side-necked turtle
Hoge’s toadhead turtle

Identification

Description

Hoge’s side-necked turtle has an elongated, slightly flattened shell with a dark brown to black carapace. The plastron is lighter in color, often yellowish or cream with dark markings. Its head is broad and slightly flattened, resembling a toad, which is a defining feature of its genus. The skin is grayish with small black speckles.

Sexual Dimorphism

Males tend to be smaller than females but have longer and thicker tails. Females generally have a rounder, more robust shell to accommodate egg-laying.

Native Origin and Distribution

Geographical Range

This species is endemic to southeastern Brazil, primarily found in the Paraíba do Sul River basin. It has a very limited distribution, making it vulnerable to habitat changes.

Preferred Habitat

Hoge’s side-necked turtle inhabits slow-moving rivers, floodplains, and freshwater lagoons with sandy or muddy bottoms. It prefers areas with abundant aquatic vegetation and submerged logs, which provide cover and basking spots.

Behavior

Feeding Habits

This turtle is an omnivore, feeding on aquatic invertebrates, small fish, plant matter, and fallen fruits. It forages in shallow waters, using its long neck to reach prey in tight spaces.

Predators

Juveniles are vulnerable to birds, large fish, and mammals. Adult turtles have fewer natural predators due to their size and protective shell but may fall victim to larger carnivorous fish or human poaching.

Reproduction

Breeding Season

Mating occurs during the rainy season when water levels are higher, typically between October and January.

Reproductive Method

Females lay small clutches of eggs in sandy riverbanks, digging shallow nests to protect them from predators. Hatchlings emerge after several months, making their way to the water independently.

Conservation

Extinction Status

Critically Endangered (IUCN Red List)

Threats

Deforestation, pollution, and hydroelectric dam construction have severely fragmented its habitat. Illegal collection for the pet trade and accidental bycatch in fishing nets further threaten its survival.

Conservation Measures

Some conservation efforts include habitat protection, captive breeding programs, and restrictions on trade. Research and monitoring initiatives aim to better understand population dynamics and ensure long-term survival.

Economic Importance

Hoge’s side-necked turtle has limited economic significance but is occasionally collected for the exotic pet trade. However, its rarity and endangered status make such activities highly regulated.

Interesting Facts

• Unlike many turtles, it cannot retract its head fully into its shell, instead bending it sideways under the carapace.
• It is one of the least studied freshwater turtles due to its restricted range and elusive nature.
• Its name honors Brazilian herpetologist Alphonse Richard Hoge, who contributed significantly to reptile and amphibian research.