Corsican brook salamander

The Corsican Brook Salamander

The Corsican brook salamander, scientifically known as Euproctus montanus, is a unique amphibian endemic to the island of Corsica in the Mediterranean Sea. This species is a member of the Salamandridae family and is distinguished by its habitat preference, primarily residing in rocky streams, springs, and rivers at altitudes generally above 600 meters. Its terrestrial skin texture differs from its smooth aquatic form, and it exhibits specific sexual dimorphism.

Description and Habitat

Corsican brook salamanders are relatively small, typically reaching about 10 cm in length, though some individuals can grow up to 13 cm. They possess a long head with a rounded snout and a tail that is oval in cross-section and roughly equal to their body length. Distinct parotoid glands are present on their necks. Males are identifiable by spurs on their hind legs and a conical cloaca that points backward, while females have a cloaca with a ventral opening. The skin is smooth when the salamander is in water but becomes more granular when it ventures onto land. Their coloration is usually brown or olive, often with orange, red, or brown mottling, especially along the spine, and a paler, uniform underside that may have white flecks but lacks spots on the throat.

This species is mainly aquatic, favoring lakes, ponds, and the slower sections of streams, often concealed beneath stones. When on land, it remains close to water sources, inhabiting maquis shrubland and woods, where it can be found undergrowth or beneath fallen logs and rocks. It is not found in eastern lowland areas or much of the coast, preferring higher elevations ranging from 600 to 1,500 meters, and can be found up to 2,250 meters.

Biology and Behavior

The Corsican brook salamander thrives in well-oxygenated waters, relying on cutaneous respiration as its lungs are either absent or vestigial. Despite this, it is capable of terrestrial movement and hibernates underground during winter. Following its breeding period, it enters a terrestrial phase and is primarily nocturnal. Its diet consists of insects and small invertebrates.

Reproduction

Breeding patterns vary with altitude. Near the coast, mating may occur twice annually, in spring and early autumn. At higher elevations, breeding takes place in midsummer. The mating ritual involves the male grasping the female with his jaws and encircling her with his tail while depositing spermatophores into her cloaca. The female then lays approximately 30 large, yolky eggs in secluded crevices or under stones. She actively guards these eggs until they hatch, which occurs about 50 days later. The larval stage, or tadpole phase, lasts for about nine months before metamorphosis into juveniles.

Conservation Status

The Corsican brook salamander is currently listed as 'Least Concern' on the IUCN Red List of Threatened Species. This status is due to its common presence in suitable habitats within its restricted range and the absence of evidence for a significant population decline. However, potential threats exist, including pollution of its aquatic environments, the introduction of competing or predatory species like trout, and habitat destruction which can lead to population fragmentation.