Fishes collected by midwater trawls during two cruises of the 



David Starr Jordan in the northeastern Pacific Ocean, 



April-June and September-November, 1972. 



J. L. Butler, H. G. Moser, W. Watson, 

 D. A. Ambrose, S. R. Charter, and E. M. Sandknop 



INTRODUCTION 



During the spring and fall of 1972 the Coastal Fisheries Resources Division, Southwest Fisheries 

 Science Center, conducted two multi-vessel ichthyoplankton/m id water trawl surveys (Cruises 7205-JD and 

 7210-JD) in a region of the eastern Pacific Ocean between 20° and 48° N latitude, from the coast 

 westward to ca. 145° W longitude. Midwater trawling was limited to that part of the sampling pattern 

 occupied by the David Starr Jordan between 20°and 31°N latitude. The major purpose of these cruises 

 was to increase our knowledge of the limits of spawning of jack mackerel. Trachiiriis svmmetricits, and 

 Pacific saury, Cololabis saira. The first results from these cruises were reported by Ahlstrom and Stevens 

 (1976) who compared catches offish eggs and larvae taken by neuston and oblique plankton nets on 7205- 

 JD. They showed that larvae of some fishes (e.g.. Pacific saury, flying fishes) reside almost exclusively 

 near the surface, some (e.g., bathylagid smelts, melamphaids) occur exclusively in the water column below 

 the surface, and others (e.g., jack mackerel) occur in both habitats. 



Another goal of Cruises 7205-JD and 7210-JD was to define the physical-biological environment 

 seaward of the standard California Cooperative Oceanic Fisheries Investigations (CalCOFI) sampling 

 pattern and, particularly, to increase our knowledge of the distribution and abundance of fish species in 

 this region. Analysis of the adult and juvenile fishes from the midwater trawl catches is a necessary 

 prerequisite to work on the ichthyoplankton, since the larvae of many groups of fishes in this region are 

 poorly known. The trawl catches provide information on the species composition, relative abundance, and 

 distribution of juveniles and adults and, also, transformation specimens that link larvae and adults and 

 allow the completion of ontogenetic series. This report presents preliminary results of the midwater 

 trawling conducted on these cruises. 



Much of what we know about the species composition, relative abundance, and zoogeography of 

 midwater fishes in the northeastern Pacific is derived from midwater trawling surveys conducted in the 

 California Current region and in adjoining water masses. Aron (1962) analyzed catches from >500 

 midwater trawls taken on three cruises from the Gulf of Alaska to the subarctic-transitional waters of the 

 northern and central California Current region. Pearcy (1964) and collaborators (Pearcy and Laurs, 1965; 

 Pearcy et al., 1977; Willis and Pearcy, 1982) contributed much information on the distribution and ecology 

 of midwater fishes off the coasts of Oregon and Washington. Berry and Perkins (1966) employed four 

 types of midwater trawls on their surveys that occupied ca. 200 stations in the CalCOFI survey area from 

 San Francisco to southern Baja California. Ebeling et al. (1970) described the composition and distribution 

 of midwater fishes in the deep-water basins off southern California and Paxton (1967) provided a 

 distributional analysis of lanternfishes that occur in these basins. Three studies (Lavenberg and Fitch, 

 1966; Robison, 1972; Brewer, 1973) characterized the distributions of midwater fish species in the Gulf 

 of California and adjoining waters of the eastern tropical Pacific. Moser et al. (1993, 1994) presented 

 summaries of the distribution and relative abundance of larvae of midwater fishes of the California Current 

 region. Our knowledge of the midwater fishes to the south and to the west of the CalCOFI survey area 

 is derived from numerous surveys, beginning with Carman's (1899) expedition. Subsequent surveys 



