The distribution of Pleoticus muelleri spans from the southern areas of Brazil to 50ºS in the Argentine Patagonia, where differences are attributed to phenotypic plasticity due to environmental conditions, but no genetic differentiation is found (Carvalho-Batista et al. 2018). Based on biological and fishery data, including reproduction areas and seasons, growth, recruitment, and fishery concentration, three independent populations have been recognized in Argentine waters for this species: Mar del Plata, Bahía Blanca, and Patagonia (Boschi 1997). 

This profile is relative to the Patagonia population, from 43º S to 47°S, considered as a single unit for stock assessment (Moriondo Donovaro et al. 2022). There are industrial and artisanal (<21m) bottom trawl fleets with specific management measures, therefore these are considered as different management units within this profile tree.