Black marsh turtles are also commonly kept as pets and as sacred animals in Southeast Asian Buddhist temples.

They are classified as endangered by the IUCN, being one of the several Southeast Asian turtle species heavily exploited for the international wildlife trade, particularly for food and traditional medicine in the Chinese markets.

[6] Black marsh turtles used to be monotypic within the genus Siebenrockiella until Diesmos et al. (2005) showed based on genetic studies and morphology, that the recently rediscovered and critically endangered Philippine forest turtles, until that time known as Heosemys leytensis, were actually very closely related.

[10] The ovoid carapace (the dorsal shell) is widest just behind the middle portion, with a strongly serrated posterior margin.

[10] The plastron (the ventral shell) is not hinged and has a shallow U-shaped notch in the pair of anal scutes.

Both the bridge and the plastron can be entirely black, dark brown, or yellowish with splotches or patterns of darker colors.

The necks of black marsh turtles are characteristically thick, forming a collar around the head when it is retracted into the shell.

[11] The markings around the eyes and throat, present in all juveniles, disappear among males upon reaching adulthood while they are retained in females.

[10] They are also notable for being the first turtle shown to exhibit an XX/XY system of chromosomal sex determination, specifically with macrochromosomes.

As their common name implies, black marsh turtles are primarily aquatic and prefer to stay buried in soft mud when not feeding.

[18] They prey on insects, worms, molluscs, amphibians, crustaceans, and small fish, though they will occasionally scavenge rotting plants, fruits, or carcasses of larger animals that fall into the water.

[18] When threatened, black marsh turtles excrete a foul-smelling secretion from their cloaca to ward off would-be predators.

[21] Captive bred black marsh turtles are preferable as pets, being healthier and more acclimated to handling than individuals captured from the wild and illegally exported.

Black marsh turtles are classified as endangered by the International Union for Conservation of Nature.

[30] Each representing just a small fraction of the actual number of wild turtles being caught and sold in the Asian markets.

In addition to this, black marsh turtles are increasingly being threatened in its native range by habitat loss.