encompassed the vertical distribution of sardine eggs and larvae. 

 Wide-ranging joint biological and oceanographic survey cruises 

 were resumed in 1949 with sardine as the focus; however, an 

 increasing interest in other biological components resulted in 

 the deepening of standard tows to 140 m in 1951. This marked the 

 beginning of truly quantitative ichthyoplankton sampling on 

 CalCOFI surveys. 



Data resulting from CalCOFI surveys in 1955 have been 

 published in a number of forms. Hydrographic data (Reid et al., 

 1962), zooplankton volumes (Staff, SPFI, 1956; Thrailkill, 1956; 

 Smith, 1971) and ichthyoplankton data for selected species 

 (Ahlstrom and Kramer, 19 57) were presented in standard formats. 

 The latter lists counts for eggs and larvae of sardine and for 

 larvae of northern anchovy {Engraulis mordax) , jack mackerel 

 (Trachurus symmetricus) , Pacific mackerel {Scomber japonicus) , 

 Pacific hake (Merluccius productus) , and rockfishes (Sebastes 

 spp.). Also, length frequencies are listed for larvae of 

 sardine, anchovy, jack mackerel and Pacific mackerel. 

 Distribution maps of larvae of 5 of these taxa taken on CalCOFI 

 surveys during 1955 are presented in the CalCOFI Atlas series 

 (Kramer and Ahlstrom, 1968; Ahlstrom, 1969; Kramer, 1970; 

 Ahlstrom et al., 1978). Other atlases provided distribution maps 

 of 6 mesopelagic fish larvae (Ahlstrom, 1972) and 8 flatfish taxa 

 (Ahlstrom and Moser, 1975) taken during 1955. 



A computer data base for eggs and larvae of sardine and 

 anchovy and for larvae of hake, and the two mackerels was 

 established in 1969. The development of a data base for other 

 fish larvae is a complex undertaking because competency of 

 identification has evolved steadily over the past 38 years. We 

 began the task of producing a CalCOFI ichthyoplankton data base 

 and associated data report series in 1983. All available 

 original records for 1955 were subjected to an extensive 

 verification and editing process to produce this report. This, 

 and previous (Ambrose et al., 1987; Sandknop et al., 1987; 

 Stevens et al., 1987; Sumida et al., 1987) and subsequent reports 

 make the CalCOFI ichthyoplankton and station data available to 

 all investigators and serve as guides to the computer data base. 

 The data base will be modified when additional errors are 

 discovered and when composite taxa from the earlier years are 

 reidentif ied. These reports are the fundamental reference 

 documents against which subsequent changes in the data base can 

 be compared. 



SAMPLING AREA AND PATTERN 



In 1955, CalCOFI survey cruises were conducted at monthly 

 intervals except during August, September and November. A total 

 of 1308 stations included in this data base was occupied on 9 

 cruises, with an average of 145 stations per cruise (range of 

 105-196) . Coverage of the survey station pattern varied 

 among cruises and the entire quarter-million square mile survey 

 area was not covered on any single cruise (Figures 1-10; Table 



