Southernmost occurrence of the slender tuna, Allothunnus fallai, off Tierra del Fuego, South Atlantic Ocean

Abstract

The slender tuna, Allothunnus fallai Serventy 1948, is an epipelagic scombrid with a circumglobal distribution in the Southern Ocean from about 20–50°S (Warashina and Hisada 1972; Collette and Nauen 1983), south to 54°S in the South Pacific (Yatsu 1995), with three exceptions from the North Pacific (Schaefer and Childers 1999). Recently, an adult male, 784-mm fork length (Fig. 1) was taken further south in the South Atlantic, at 53°25′S, 64°23′W off Tierra del Fuego, Argentina. It was caught while trawling at 167 m on March 12, 2007 by the fishing vessel Tai An. The surface water temperature was 8°C and the salinity 33.59 parts per thousand (ppt). The specimen has been deposited in the fish collection of the Instituto Nacional de Investigación y Desarrollo Pesquero under number INIDEP 801.