[6] Similar fish include the Bald Notothen (Pagothenia borchgrevinki) and the Stocky rockcod (Pagothenia phocae), who have two supraorbital pores (instead of one), the Striped rockcod (Trematomus hansoni), who have 27–33 pectoral rays, and the Bigeye Notothen (Trematomus tokarevi), who do not have green spots at their pectoral fin base.

[6] It prefers inshore bottom waters that are rocky and covered in macroalgae, which it feeds and lay eggs.

[7] Emerald rockcod spawn from October to November off the Adelie Coast[5] and December to January in McMurdo Sound.

[9] This could be due in part to a reproductive strategy, as Emerald rockcod are one of few species that have demonstrated parental care, with females found in egg-guarding positions within Rosella nuda sponges.

Emerald rockcod are a generalized species, consuming various invertebrates, small fishes, and also are known to feed on some algae.

[1] While its prey is on a wide trophic spectrum, most often it is found to consume amphipods, infaunal and epifaunal polychaetes, and molluscs.

In shallow water, foraging techniques make it the primary predators of the Antarctic scallop (Adamussium colbecki).

[11] In deeper waters, Antarctic scallop no longer appear, and this population instead feed on abundant infaunal or epifaunal polychaetes.

[12]This species has relatively high jaw closing pressure, which assists them in durophagous feeding, especially the consumption of Antarctic scallop.

[16] Elevated seawater temperatures have been observed to affect the metabolism of Emerald rockcod at the organism level.

Living in a rapidly warming extremist climate region, Antarctic fish are especially vulnerable to temperature changes.

Upon acclimation to temperatures up to 4°C over 9 weeks, this species was observed to have a 84% reduction in mass growth, even while having comparable food consumption to control groups at 0°C.

Antarctic fish are especially vulnerable when juveniles, as the growth reduction will likely delay sexual maturity and fecundity.