HLCHARD EGGS AND LARVAE ANT OTHER FISH LARVAE ^ 

 PACinC COAST, 1950 



By Elbert H. Ahlstrom 



This report contains records of the quantitative sampling of fish 

 eggs and larvae off the west coast of North America during 1950 o The 

 5.rea Included is roughly that lying between the Colximbia River and Punto 

 Abreojos, Lower California, and extending 350 to UOO miles off shore » 

 The species included are the pilchard or sardine ( Sardinops jaerulea ), 

 northern anchovy (E ngraulis mordax ) , jack mackerel" ( Trachuras sj^ Tnmetricus ) ^ 

 halce ( Merluccius productus ;. and rock fish ( Sebastodss 5pp.)e 1/ 



In the tables, pilchard larvae are enumerated by size categories, 

 and pilchard eggs by age (in da^/B) since spavjning. Northern anchovy 

 larvae are also enumerated by size categories. Tabulations are given 

 of the numbers of jack mackerel, hake, and rock fash, three of the 

 most abundant species in the collections. In addition, haul data are 

 given for all collections taken during cruises 11 through 16, February 

 through September, 1950. Descriptions of the eggs and larvae of the 

 jack mackerel and hake are being prepared for early pubiicationo 



The purpose cf this report is to put these data on recordo 

 Analyses of the data will be presented in subsequent publications o 



The investigation of the distribution and abxindance of pilchard 

 eggs and larvae is one of the major lines of research being pursued 

 by the South Pacific Fishery Investigations of the U. S. Fish and 

 Wildlife Service under the California Cooperative Sardine Research 

 Program* This program is sponsored by the Marine Research Committee 

 and is being carried out in conjunction with the Scripps Institution 

 of Oceanography of the University of California, the California 

 Department of Fish and Game, the California Academy of Sciences, and 

 the Hopkins Marine Station of Stanford University. 



It is a pleasure to acknowledge the wholehearted cooperation of 

 the Scripps Institution of Oceanography, both in the collection of 

 data at sea and in its processing ashore. The whole staff of the 

 Scuth Pacific Fishery Investigations of the Fish and Wildlife Service 

 contributed to this investigation, with the majority of the workers 

 devoting their full time to it. When it is pointed out that about $0 

 persons participated in each cruise, either in the collecticn of 

 material or in the operation of the vessels, and that nearly half this 

 number of persons worked iidth the material ashore, it will be e'rident 

 why it is impracticable to include individual acknovjledgments. 



1/ The collections were designed primarily to yield information on 

 pilchard o Information on the other species is partially an incidental, 

 although not ur.expected byproducto 



