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BULLETIN OF THE BUREAU OF FISHERIES. 
fish industry in this country, where vast numbers are not only eaten but used to supply 
classes in zoology or some phase of nature study in nearly every State of the Union. 
Professor Andrews,® from whose paper the following statistics are taken, thinks 
that the demand for the fluviatile crayfish is likely to grow steadily, and may help to 
counterbalance the waning supplies of marine food, especially in the form of lobsters 
and crabs. 
The crayfish of the eastern central regions belong to the genus Cambarus, the Poto- 
mac supplying C. affinis; Chicago, C. virilis; New Orleans, C. blandingii; and Montreal, 
C. bartoni. A considerable fishery for the large and handsome American species of 
Astacus, a counterpart of the European form, has been developed on the Pacific coast. 
This centers in Portland, Oreg., where, in 1899, the product reached 117,696 pounds, 
valued at $19,556. 
Andrews has shown that the common Cambarus affinis not only breeds annually, 
but that its young reared from spring eggs may in turn lay eggs the spring following, 
when under a year old, while at the age of 3JJ years they attain the average market 
size of 4 inches. It is further suggested that the large 6-inch Oregon Astacus, which is 
more lobster-like in appearance, could doubtless be successfully introduced into Eastern 
waters, and, with a growing demand, profitably reared, since there is no reason to 
suppose that climatic changes would offer any obstacle to its development. 
The prawns and shrimps distributed among the various families enumerated are 
undoubtedly the most active and most graceful, as well as the most plentiful of all the 
decapod Crustacea. Many species are highly valued as food, and are netted and sent to 
market in vast numbers over a large part of the world. The most important shrimp 
fisheries of the United States center in the Coast States of the Gulf of Mexico and 
Pacific Ocean. 
Among the best-known species in North America are the edible shrimp of the South 
(. PencBus setiferus and P. brasiliensis ) , the still more abundant common shrimp ( Crangon 
vulgaris), found on both coasts and closely related to the common European shrimp 
The California shrimp ( Crangon jranciscorum) , the largest and most important of the 
edible species on the western coast, attains a length of 3 inches. It not only supplies 
abundantly the local markets, but occupies an important place in the export trade of 
San Francisco, being boiled, dried, and shipped to China in large quantities. 
Prawns are extremely abundant in the East Indies from Japan to Australia, and, 
commercially considered, are the most important Crustacea of the Orient. Thirteen 
species of the genus Penceus alone are taken in Japanese waters. “They are highly 
prized and extensively used as food and bait, and dried prawns annually exported to 
China amount to about 900,000 kilograms in weight and to about 200,000 yen 
($131 ,000) in value. The dried prawns belong almost exclusively to the genus Penceus.” b 
Closely allied to prawns, though placed in a distinct family, are the Alpheidae, of 
which over 100 species of snapping shrimps belonging to the genus Alpheus and 
Synalpheus alone have been described. They are essentially tropical, and abound in 
a Andrews, E. A.: The future of the crayfish industry. Science, n. s., vol. xxin, 1906, p. 983-986. New York. 
^Kishinouye, K.: Japanese species of the genus Penaeus. Journal of the Fisheries Bureau, Tokyo, vol. vm, 1900, no. 1, p. 1-29. 
