The common life habit of Antarctic fish is that they like to live in deep water, and there seems to be no dense surface fish, which is in sharp contrast with other oceans.
Antarctic fish are relatively small, most species are less than 25 cm in length, and few are more than 50 cm in length. Only toothfish of Haddock family can reach 1.8 m in length and weigh 70 kg. Most fish grow slowly, generally increasing their body length by 2 ~ 3 cm every year. Only the big-toothed bearded fish can grow about 7 cm a year, and it can grow to 50 cm in 7 years.
The spawning season of Antarctic fish is in late autumn and early winter in the southern hemisphere. Eggs are large, generally 2 ~ 4 mm in diameter and 8 mm in maximum. They are round, full of yolk and rich in nutrition. In spring, fish eggs hatch into small fish. At this time, the phytoplankton in the Southern Ocean is in the season of mass reproduction, which provides a direct or indirect source of nutrition for the growth of young fish. Most fish feed on marine zooplankton, and some also eat some phytoplankton.
The blood of most Antarctic fish is not red, but gray, because there is no hemoglobin. Fish in the southern ocean are mainly distributed in some waters south of the Antarctic convergence zone, especially in the waters near the islands, and the number is more abundant.
Due to the slow growth, small size and low yield of Antarctic fish, it is easy to destroy its resources and even dry up some sea resources due to overfishing. For example, the South Georgia Sea used to be quite rich in fish resources, and after several years of continuous fishing, only 20% of the resources remained. At present, the international community has taken protective measures for this sea area and kerguelen sea area to solve the problem of sharp decline of fish resources in some sea areas.
Although it is generally believed that the exploitation value of southern ocean fish is not as great as that of krill, whales and other biological resources, with the deepening of the investigation of Antarctic marine biological resources, the living habits and quantitative distribution of Antarctic fish will gradually become clear, and its potential value will also emerge.