Escape performance in the sub-Antarctic notothenioid fish Eleginops maclovinus

Abstract

Fast-start performance associated with escape behaviour was investigated in the sub-Antarctic notothenioid Eleginops maclovinus from the Beagle Channel, Tierra del Fuego, Argentina (mean winter water temperature 4°C, mean summer water temperature 10°C). Fish acclimated to 8.5°C for 2 months were filmed at 2, 4, 6, 8 and 10°C. Escape responses were temperature dependent over the range of temperatures tested. Maximum length-specific velocity $$(\hat V_{\max } )$$ , maximum length-specific acceleration (Â max) and inertial power output (P iner) increased significantly with temperature. Q 10 values for $$\hat V_{\max } $$ , Â max and P iner were 1.90, 3.27 and 8.90, respectively. Non-dimensional curvature of the spine $$(\hat c)$$ also varied significantly with temperature, but was higher at low temperatures. The values of $$\hat c$$ were threefold lower than previously reported for Antarctic notothenioids and similar to the values for temperate species. The results indicate that the high values of $$\hat c$$ observed during escape behaviour in Antarctic notothenioids are not a universal feature of the suborder. A greater flexion of the body during fast starts is therefore a promising candidate for a specialised feature of behaviour linked to low-temperature performance.