Growth Patterns and Body Condition of Notothenioid Fish (Genus Trematomus) From the Antarctic Peninsula and Weddell Sea

Abstract

Growth patterns and body condition of 10 species of Trematomus (family Nototheniidae) collected off the Antarctic Peninsula and in the Weddell Sea during seven cruises carried out between 2002 and 2022 were estimated by length–weight relationships (LWRs) and relative condition factors (K_rel). Most of the investigated species exhibited positive allometric growth, except for males of T. scotti and females of T. tokarevi, which showed isometric growth. Sex-related differences of slope (b) in the LWRs were recorded only in T. eulepidotus and T. scotti. No slope differences were found when comparing populations from the two sampling areas. The form factor, derived from the LWR parameters, was a reliable indicator of body shape and was consistent with the mode of life of each species. K_rel was evenly distributed around unity, although data dispersion differed among the species. The overall similarity of growth patterns and body condition among the different species of Trematomus was likely due to their genetic similarity and common life history strategies despite their wide spatial distributions and different modes of life.