The Antarctic butterfish, deepsea trevally, blue eye trevalla, bluenose sea bass, or deep sea trevalla, Hyperoglyphe antarctica, is a medusafish

Medusafish

Medusafishes are a family, Centrolophidae, of perciform fishes. They are found in temperate and tropical waters throughout the world.Young Icichthys lockingtoni are abundant in the coastal waters of the north Pacific, where they are often found in association with jellyfish, which provides them...

 of the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Centrolophidae found in all the southern oceans, at depths of between 40 and 1,500 m. Its length is up to about 140 cm, with a maximum published weight of 60 kg.

Antarctic butterfish have a dark blue body above and lighter blue below with large eyes (another name for this fish is big eye). Larger individuals have a bronze sheen along the flanks.

They can grow to 1.4 m in length and over 50 kg in weight. Studies have shown that fish between 62 and 72 cm are mature

Sexual maturity

Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...

 and range in age between 8–12 years respectively. Mature females can produce between 2 million and 11 million eggs

Roe

Roe or hard roe is the fully ripe internal egg masses in the ovaries, or the released external egg masses of fish and certain marine animals, such as shrimp, scallop and sea urchins...

 prior to spawning

Spawn (biology)

Spawn refers to the eggs and sperm released or deposited, usually into water, by aquatic animals. As a verb, spawn refers to the process of releasing the eggs and sperm, also called spawning...

.

Blue eye mainly feed on the tunicate

Tunicate

Tunicates, also known as urochordates, are members of the subphylum Tunicata, previously known as Urochordata, a group of underwater saclike filter feeders with incurrent and excurrent siphons that is classified within the phylum Chordata. While most tunicates live on the ocean floor, others such...

 Pyrosoma atlantica. However they will feed on a range of fish, molluscs, squid

Squid

Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...

 and crustacean

Crustacean

Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...

s, they are also cannibalistic.

Reproduction and distribution

Spawning appears to occur in an area north east of Tasmania

Tasmania

Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...

 during March and April.

Little is known about the egg and larva

Larva

A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...

l stages of blue eye. Recently Antarctic buttefish of approximately 10 cm have been found living in association with large masses of floating kelp

Kelp

Kelps are large seaweeds belonging to the brown algae in the order Laminariales. There are about 30 different genera....

. It is believed that as these juveniles reach 50 cm they become semi-bottom dwelling.

These young fish form schools

Shoaling and schooling

In biology, any group of fish that stay together for social reasons are said to be shoaling , and if, in addition, the group is swimming in the same direction in a coordinated manner, they are said to be schooling . In common usage, the terms are sometimes used rather loosely...

over hard bottom at depths of around 350–450 m, moving to deeper waters as they grow.