Distribution of three Antarctic white blood icefish Pseudochaenichthys georgianus, Chaenocephalus aceratus, and Champsocephalus gunnari in the Antarcti sectors of the Atlantic; the changes of otolith shape

Materials collected between 1986 and 2006 from Antarctic research cruises in the area of Scotia Arc Islands allowed to present the geographical distribution of different development stages of Ps. georgianus, depending on the currents and the presence krill in them. Ps. georgianus has krill as dominant food. Postlarvae and younger fish were at the south-western sides of Island shelves at the depths below 200 m, where currents are weaker than surface and contain juvenes and small krill. The older fish, over 3, 4 years old, were numerous on the north - eastern sides of Islands shelves in the regions of strong vortices, which concentrate krill. That larger and older fish (over 3, 4 years old) swims 4 times faster than post-larvae and have otolith more flattened (1/3) and elongated. The least flattened and elongated otoliths (as like the body that are most stocky) has Ps. georgianus in compare to similar C. aceratus and C. gunnari and has the smallest geographical occurrence: from Palmer Archipelago to S. Georgia. The least elongated otoliths means the heighest otolith, that reflects the highest body of Ps. georgianus and in swimming the highest reducing the drift off shelf.