[3] Icefishes, also called white-blooded fishes, are a unique family in that they are the only known vertebrates to lack haemoglobin, making their blood oxygen carrying capacity just 10% that of other teleosts.

[5] The blackfin icefish was first formally described as Chaenichthys aceratus in 1906 by the Swedish zoologist Einar Lönnberg with the type locality given as South Georgia Island.

The specific name aceratus means "no horned" an allusion to the lack of a spine on the snout of this species in comparison to what was then thought to be its congener Channichthys rhinoceratus.

Larvae and juveniles tend to be more active in the water column but are typically found closer to the shore, while adults more often exhibit benthic swimming behaviour.

This current formed 25–22 million years ago, and thermally isolated the Southern Ocean by separating it from the warm subtropical gyres to the north.

In addition, icesfishes have developed a specialized cardiovascular system to compensate for the lack of hemoglobin and maximize oxygen delivery to tissues.

[16] Icefish also possess an enlarged, hypertrophied heart, which allows the animal to pump very large volumes of blood at a low pressure and speed.

From data collected in different locations, researchers have determined that the blackfin icefish likely feeds sporadically, consuming large quantities of fish and krill at a time, but at irregular intervals.

While larvae and juveniles are more active in the water column searching for krill, the adult blackfin icefish usually works as an ambush predator, sitting on the substrate until prey swim past.

[5] The blackfin icefish takes between 5 and 7 years to reach reproductive age, and it expends a large amount of energy when it comes to reproducing and parenting.

[5] Males dig shallow, circular depressions on the seafloor and clear the surrounding area of debris for a female to spawn her eggs.

The embryos are at high risk of predation because they are demersal, so males spend the months between spawning and hatching ferociously guarding the eggs.

However, because reproduction requires large amounts of energy and icefish are limited due metabolically to lack of haemoglobin, sexually mature females may skip a season of spawning if food has been scarce or of poor quality.

[19][9] Even if the blackfin icefish is thrown back after being caught, it has a high mortality rate due to its fragile structure and vulnerability to stress.

[9] Researchers are currently working to understand how marine protected areas can be created for this species, and the best ways to handle them to reduce stress and injury.