Notes on Larvae, Juveniles, and Spawning of Bonito ( Sarda ) 
from the Eastern Pacific Ocean 
W. L. Klawe 1 
Two species OE bonito occur along the Pacific 
coast of the Americas (Hildebrand, 1946) 2 
Sarda chiliensis ranges from southern British 
Columbia to northern Chile; the other species, 
S. orientalis , is found from Baja California to 
the Galapagos Islands and northern Peru. These 
species are of considerable importance to both 
commercial and sport fisheries of certain coun- 
tries (Walford, 1937; Berdegue, 1956). The 
bonito fishery in Peru, especially for S. chilien- 
sis, is particularly important. It contributes sig- 
nificantly to the economy, being valuable to the 
domestic market as well as for export. The fol- 
lowing table gives the commercial catches of 
bonito, expressed in thousands of metric tons, 
during the past few years : 
OFF PERU 
OFF 
CALIF. 
WORLD 
TOTAL 
1950 
31.8 
0.3 
61.6 
1951 
51.2 
0.4 
76.9 
1952 
50.3 
1.0 
76.1 
1953 
44.4 
1.4 
83.8 
1954 
52.8 
1.1 
114.4 
1955 
71.8 
0.1 
173.1 
1956 
83.4 
0.1 
189-9 
1957 
58.6 
0.1 
145.5 
1958 
66.2 
2.4 
163.5 
Despite the commercial importance of bo- 
nitos, knowledge of their biology is relatively 
meager. Little is known of the early life his- 
tory and spawning, and descriptions of the eggs, 
larvae, and juveniles of Sarda are limited to a 
few reports. The only descriptions of young 
1 Inter- American Tropical Tuna Commission, La 
Jolla, California. Manuscript received September 26, 
I960. 
2 It is assumed that S. lineolata (Girard) ~S. chilien- 
sis (Cuvier and Valenciennes) and that S. velox Meek 
and Hildebrand = S: orientalis (Temminck and Schle- 
gel). S. chiliensis and S. sarda from the Atlantic Ocean 
and adjacent seas may be synonymous. A detailed dis- 
cussion on the relationship of the species of the genus 
Sarda is provided by Godsil (1955). 
bonitos from the eastern Pacific Ocean are those 
of S. chiliensis by Barnhart ( 1927 ) and Orton 
(1953*, 1953 h). Descriptions of eggs and young 
from other parts of the world seas are limited 
to the reports listed in Table 1. 
The information on spawning of bonito is 
scant. According to Yildoso (1955), S. chilien- 
sis reproduces in Peruvian coastal waters from 
October to March with the peak of spawning 
occurring from December to February. From 
Barnhart’s work (1927) it is' evident that off 
La Jolla, California, S. chiliensis spawns in June. 
Walford (1937) stated that in the northern 
latitudes this species spawns during the late 
spring and summer close to shore to as far out 
as 80 mi. Observations on spawning bonito in 
other parts of the world are limited to the 
reports on S. sarda tabulated below: 
SPAWNING 
AREA 
TIME 
REFERENCE 
Mediterranean.. 
May-jun. 
Sanzo, 1932 
Black Sea 
Apr.-Aug. 
Borcea, 1939, 1933 
Vodyanitsky, 1936 
Malyatsky, 1940 
Muman, 1955 
Atlantic, 
off Morocco.. 
Jun —Jul. 
Furnestin et ah, 1958 
off Dakar 
Feb --Mar 
Frade and Post'd., 1955 
U.S. coast 
Jul. 
Sette, 1943 
Jun. 
Bigelow and Schroeder, 
1953 
During the course of collecting biological 
material and other scientific data from commer- 
cial fishing vessels and research ships operating 
in waters of the eastern Pacific Ocean, staff 
members of the South Pacific Fishery Investiga- 
tions of the U. S. Bureau of Commercial Fisher- 
ies, Scripps Institution of Oceanography, and 
the Inter-American Tropical Tuna Commission 
have captured a variety of larval and juvenile 
fish, including young of Sarda. The data on the 
collections of young bonito made by these or- 
ganizations with some other records, kindly put 
487 
