Escape performance in the sub-Antarctic notothenioid fish Eleginops maclovinus.

DANIEL ALFREDO FERNANDEZ; JORGE CALVO,; JAMES WAKELING,; FABIÁN VANELLA,; ALISTAIR JOHNSTON, IAN

POLAR BIOLOGY

Año: 2002 vol. 25 p. 914 - 920

0722-4060

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 4C, mean summer water temperature 10C). Fish acclimated to 8.5C for 2 months were filmed at 2, 4, 6, 8 and 10C. Escape responses were temperature dependent over the range of temperatures tested. Maximum lengthspecific velocity ð^VmaxÞ, maximum length-specific acceleration (Aˆ max) and inertial power output (Piner) increased significantly with temperature. Q10 values for ^Vmax, Aˆ max and Piner were 1.90, 3.27 and 8.90, respectively. Nondimensional curvature of the spine ð^ccÞ also varied significantly with temperature, but was higher at low temperatures. The values of ^cc 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 ^cc 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.