Calanoid Copepods from Midwater Trawl Collections Made in the Southeastern Pacific Ocean1

IN ADDITION TO the fishes and faster swimming invertebrates (euphausiids, squids) usually ob-tained in midwater trawl collections, relatively large species of copepods are also frequently captured. Aside from Sewell's (1929) report of copepods found in six midwater collections made in the Ind ian Ocean, it has only been in recent years that midwate r trawl samples have been more or less systematically analyzed for copepods. From the Florida Current, off Miami, an area in which the copepods have been stud ied fairly extensively, Owre and Foyo (1964) re-ported that 21 calanoid species were found only in collections made by the Isaacs-Kidd midwater trawl (Isaacs and Kidd, 1953). Of these, 11 represented new records for the area. In the southwestern Indian Ocean, De Decker and Mombeck (1965) using both vertical plankton net and midwater fish trawl found 274 species of copepods. Of these the fish trawl accounted for 115 species including 43 which were not found in the plankton net collections. In the western Indian Ocean Grice and Hulsemann (1967) studied a series of 30 plankton net and 21 midwater trawl collections obtained between 18°N and 40 0S. In the midwater trawl col-lections were found 64 species not present in the plankton net collections, including representa-tives of all eight species of the family Mega-calanidae. It thus appears that midwater nets constitute a valuable additional means of sam-pling the calanoid copepod fauna in an open ocean area, and it is hoped that those interested in copepods will examine any available mid-water trawl samples. The samples examined in this study wer