The Vertical Distribution of Mesopelagic Fishes Collected on the SOND Cruise

Abstract

The features of the vertical distribution of meso- and bathypelagic fishes are poorly known. Much of our present knowledge is based upon data collected on the early, major expeditions (i.e. Brauer, 1906; Murray & Hjort, 1912; Jespersen, 1915; Jespersen & Tåning, 1926; Norman, 1929, 1930; Regan & Trewavas, 1929, 1930; Benin, 1934, 1937; Ege 1934 1948, 1953, 1957; Bertelsen, 1951; Parr, 1960; Ebeling, 1962; Ebeling & Weed, 1963; Nafpaktitis, 1968). Fishing depths were not accurately determined, the depth of net generally being calculated from the length of wire out and the wire angle to the water surface. Closing nets were infrequently used. From these reports a general appreciation of vertical distributions has been possible. More recently, distribution studies mostly made in restricted areas using open nets with depths more accurately determined indicate a limited vertical distribution for each species (Aron, 1962; Pearcy, 1964; Pearcy & Laurs, 1966; Lavenberg & Ebeling, 1967; Paxton, 1967).