(Conger cinereus) is an intriguing eel species that belongs to the Congridae family, which consists of conger and garden eels found in tropical and temperate waters around the world. Moustache Congers are native to the Eastern Atlantic Ocean, from the Bay of Biscay to South Africa, and throughout the Mediterranean Sea.

Moustache Congers typically grow up to 3-4 feet (90-120 cm) in length, with some exceptional individuals reaching lengths of up to 6.5 feet (200 cm). This makes them one of the larger members of the Congridae family.

The basic shape and features of the Moustache Conger resemble those of other conger eels, with a long, cylindrical body that tapers towards the tail. The head is large and slightly flattened, with a wide mouth equipped with sharp teeth for capturing and holding onto prey. The eel's most distinguishing feature is the presence of a pair of elongated, fleshy barbels located at the corners of the lower jaw, resembling a mustache, which gives the species its common name. These barbels serve as sensory organs that help the eel locate food.

The body coloration and pattern of the Moustache Conger is predominantly brownish-gray to dark gray on the dorsal surface, transitioning to a lighter gray or cream color on the ventral surface. This relatively simple coloration provides the eel with effective camouflage against the rocky and sandy substrates it inhabits. Juvenile Moustache Congers may exhibit faint bands or blotches on their bodies, which fade as they mature.

Socially, Moustache Congers are solitary and somewhat secretive. They are primarily nocturnal, spending their days concealed in caves, crevices, or under rocks and emerging at night to hunt for food. Their diet mainly consists of fish, crustaceans, and cephalopods. During the breeding season, Moustache Congers congregate in groups to spawn, after which the adults usually perish, and the young eels begin their life cycle.

Moustache Congers are not common in the aquarium trade due to their large size and specific requirements. However, if kept in captivity, they need a large aquarium with ample hiding spaces and a suitable environment that mimics their natural habitat. Tankmates should be chosen carefully, as Moustache Congers may prey upon smaller fish and invertebrates.

In conclusion, the Moustache Conger is a fascinating species of eel characterized by its large size, unique mustache-like barbels, and nocturnal behavior. Its secretive lifestyle and specific habitat requirements make it a challenge to study in the wild and maintain in captivity, but its captivating appearance and intriguing biology continue to attract the attention of marine biologists and enthusiasts alike.