Black-bellied salamander

The Black-bellied Salamander

The Black-bellied salamander, historically known as Desmognathus quadramaculatus, is a species of salamander native to the Appalachian Mountains in the southeastern United States. It is the largest member of the Desmognathus genus, commonly referred to as dusky salamanders, which is the second-largest genus of plethodontid salamanders in the eastern U.S. While once considered a single species, recent scientific research has reclassified the Black-bellied salamander group into multiple distinct species, rendering Desmognathus quadramaculatus a synonym.

Description and Distribution

These salamanders are medium-sized, typically measuring between 10 to 18 centimeters (3.9 to 7.1 inches) in length. They possess a sturdy build and a long tail. Their coloration is generally dark brown to black, often featuring two rows of small, pale spots along their backs. The underside is predominantly black, though younger individuals may display pale flecks. Coloration can be highly variable, ranging from light gray to deep black, and has been observed to be influenced by specific habitat characteristics such as shade, leaf litter, and the color of surrounding rocks. The species is found in the Appalachian Mountains, with its range extending through West Virginia, Virginia, Tennessee, North Carolina, South Carolina, and Georgia.

Habitat and Behavior

The Black-bellied salamander is a largely aquatic species, favoring cold mountain streams, rivers, and freshwater springs at elevations between 375 and 1,725 meters. It spends more time in the water compared to most other Desmognathus species, with the exception of the shovelnose salamander. While they forage primarily on land, they maintain a small home range close to the stream, rarely venturing more than 30 centimeters away. Within this territory, they utilize crevices or burrows as refugia, ambushing passing invertebrates. Their diet is diverse and changes with age, encompassing insect nymphs, aquatic and aerial prey, and even other salamanders in adulthood. They are known to aggressively defend these refugia, sometimes leading to cannibalism among conspecifics.

Reproduction and Ecology

Breeding occurs in the late spring. Females deposit between fifteen to forty eggs at the base of submerged boulders. The eggs typically hatch after about three months, and the larval stage is prolonged, with metamorphosis into juveniles taking around three and a half years. Research indicates that these larval salamanders can distinguish between different fish species, recognizing predators. In their ecosystem, Black-bellied salamanders interact with other salamander species, sometimes displacing or preying upon species like the dusky salamander. They also appear to actively avoid seal salamanders, possibly through chemical cues. Defense strategies include warning coloration, immobility, biting, and tail autotomy. Despite its defenses, the species is sometimes preyed upon by garter snakes and shrews.

Conservation Status

Listed as 'Least Concern' by the IUCN Red List, the Black-bellied salamander is considered to have a stable population of at least 10,000 individuals. However, potential threats include localized declines due to stream acidification from mining activities and capture by fishermen for use as bait.