244 
BULLETIN OF THE BUREAU OF FISHERIES 
and range from 14 to 20, with means of 16.61 to 17.23 in the Pacific. Clearly neither 
the dorsal nor anal rays can be used as a specific character. 
This leaves only a few minor characters with which to differentiate between 
individuals of the two species. However, Averinzev (1928) shows that the number 
of caudal and precaudal vertebrae and the number of keeled scales is practically the 
same between herring of the White Sea and a sample of Pacific herring from near 
Vladivostok, tie believes the two species to be connected by forms extending across 
northern Siberia. 
DISTRIBUTION AND SIZES 
RANGE 
The Pacific herring is found along both shores of the North Pacific, ranging from 
San Diego Bay on the south, north and west to the Aleutian Islands, and across to 
Japan and Siberia. They occur on both shores of Bering Sea, extending at least to 
Bering Strait. On this coast they occur in sufficient abundance in British Columbia 
and Alaska to support a considerable industry. 
SIZE AND OCCURRENCE OF YOUNGER AGE GROUPS 
In the herring, as in most pelagic fishes, the schools are not uniform as to the 
sizes and ages of the individuals contained therein. There is differential schooling, 
according to size, age, and sexual maturity. The degree and kind of segregation will 
vary at different seasons of the year, the schooling at spawning time depending 
chiefly on the state of maturity. The individuals in their first year are very small ; 
those in Cook Inlet, from scale studies given later, are shown to be about 60 to 70 
millimeters in body length when a year old. Fraser says (1916, p. 107) concerning 
the herring in the Straits of Georgia, “After a couple of weeks there is a gap until the 
fish is about 6% months old on October 9. By this time the average length is about 
5.2 centimeters and the weight 1.5 grams. The scales are already well started. On 
February 16 they have reached a length of 6.3 centimeters; April 4, 6.5 to 7.0 centi- 
meters; and on May 16 (14 months), 7.6 centimeters.” Thompson (1916, p. S48) 
gives the length frequencies of three samples of young herring taken in British Colum- 
bia in October, 1916, the samples varying from 6.7 to 7.7 centimeters in average 
length. 
Very little is known as to the distribution of herring of this size, except that they 
can often be seen in immense numbers, never far from shore. We obtained a sample 
in Flalibut Cove Lagoon with a fine-meshed beach seine, and Will F. Thompson 
obtained a sample at Yakutat by means of a fight and a lift net. 
During the summer of their second year the herring are about 120 to 140 milli- 
meters in body length. In many of the inlets herring of this size are extremely 
numerous, and during the summer months the surface of the water close inshore often 
appears as though sprinkled with fine rain when they are feeding at the surface. 
Herring of this size are only occasionally taken with the larger sizes. The fishermen 
rarely deliberately make a catch of this size alone as they gill in the seines causing a 
great deal of extra work. 
OCCURRENCE OF MATURE HERRING 
The mature herring must approach the shore at least once each year in order to 
spawn. After spawning, the spent herring may disappear for a time. Whether they 
go into deeper water or are merely widely scattered is uncertain. In a few localities, 
as San Diego and San Francisco Bays, this spawning period is the only time at which 
the herring are observed and taken. In Alaska they spawn in late spring and then 
