Rattail Fish

Rattail Fish (Coryphaenoides acrolepis)

Rattail Fish (Coryphaenoides acrolepis) are by far the most common fish on Axial. Photo credit: NSF-OOI/UW/CSSF; Dive R1601; V13

The common names Rattail and Grenadier refer to a group of large, brown to black, deep sea fish from the family Macrouridae. The group is characterized by their large heads and slender bodies that narrow into a thin tail, from which they get their common name. They are also known for their large mouths and eyes. As a family they are considered to be one of the most abundant deep sea fish. Young Coryphaenoides acrolepis are typically gray to grayish brown, and turn darker with age.

Rattails have long life spans. Coryphaenoides acrolepis as old as 73 years have been reported. They are generalists when it comes to feeding, eating smaller fish, crustaceans, cephalopods and others. They are considered an apex predator of their ecosystems.

Rattail fish are extremely common at Axial Seamount, and can be seen near the vents and in the surrounding areas. They generally range between 46 – 65cm (18 -25.5in) in length. The largest measured specimen was 104cm (41in).