FISHES OF CHESAPEAKE BAY 
53 
Length, inches 
Embryos or eggs 
Length, inches 
Embryos or eggs 
28K - - - --- 
3354... 
4 embryos. 
1 large egg. 
4 embryos. 
Do. 
5 embryos. 
31 
2 embryos. 
Do. 
1 embryo. 
2 embryos. 
4 embryos. 
'Do 
31)4 - -- 
34>4 ... 
~Do 
3514 
32 - 
35^1- 
32'A 
This table agrees with the examinations of other investigators in that the number of young 
produced at one time usually is not more than four. It also suggests that larger fish produce more 
young than smaller fish, a fact noted also by Ford (1921, p. 473). The size of most of these embryos 
was 6 to 7 inches. At the time of birth dogfish are from 9 to 12 inches in length. Young appear 
to be born in the spring and autumn. If the period of gestation is 10 to 11 months, as probably 
is the case, a female can not give birth to young both in the spring and in the fall. 
The spiny dogfish is generally common in the lower part of Chesapeake Bay, below the Potomac 
River, during the late fall and early spring. Nothing is known of its presence there in the winter, as 
fishing in the lower bay ceases entirely during this period. It is probable, however, that, due to the 
depleted food supply and the low water temperatures, it is scarce if not entirely absent during the 
winter. During the summer, at least from late May to October, it is entirely absent. Dogfish 
travel in schools, often appearing suddenly and irregularly. A set of two pound nets in Lynnhaven 
Roads, Va., caught spiny dogfish beginning with the first day’s fishing — March 6, 1922. A few 
(perhaps less than 10) were taken nearly every day throughout the month. On April 4, when we 
began field operations in this locality, 25 were caught, followed by 8 on April 6 and 6 on April 8, all 
2^4 to 3 feet in length. It was of interest to note that all of these were taken by the pound net set 
in 32 feet of water, whereas the other net, placed in 12 feet of water and leading inshore directly 
from the deep-water net, caught none. On May 25, when these nets were again visited? no spiny 
dogfish were caught, nor had any been taken since early in May. At Cape Charles, Va., the fisher- 
men reported this shark common in March and April. In the fall the spiny dog appears in 
apparently smaller numbers than in the spring. Our earliest record is November 15, 1922, when a 
28)^-inch fish was caught off Willoughby Spit, Va. Only stragglers are taken in pound nets late 
in November, or at the time when fishing ceases for the winter. Inquiries among the fishermen 
along the lower Potomac revealed that the spiny dogfish is not taken there, hence we can state 
with assurance that it is restricted to the lower parts of the bay, being most abundant near the capes. 
Spiny dogfish are exceedingly abundant off the New England coast, at least from Nantucket 
Shoals to Cape Sable, Nova Scotia. They are present in this region from May until late October, or 
during the time when they are absent from Chesapeake Bay and points farther south. Along the 
New Jersey coast and western Long Island they appear suddenly in great numbers early in 
November, and are then regarded by fishermen as the forerunners of the cod. They soon disappear, 
however, and are not seen again until late April and early May, when they are present only a few 
weeks. Little appears to be known concerning the winter home of this dogfish. Their appearance 
south of New England directly after they leave and before they return would indicate a coastwise 
movement. Although they may occur as far south as the Carolinas, and to a more limited extent 
farther south, evidence produced by Bigelow and Welsh (1925, p. 47) indicates that the predominat- 
ing migration is on and off shore rather than alongshore. 
Spiny dogfish are usually from 2 to 3 feet long and attain a length of at least 2>}4, and possibly 
4 feet. Females average somewhat heavier than males. 
This shark is of no commercial importance in Chesapeake Bay and does not occur there in 
sufficient numbers to be regarded as a serious pest by the fishermen. Wherever abundant, it is 
destructive to other fish and fishing gear; because of this and its strong dorsal spines, with which 
it can inflict painful wounds, it is considered obnoxious by all fishermen. 
Habitat . — On both coasts of the Atlantic; on the American Continents from Labrador to 
Uruguay, occasionally straying northward to Greenland. 
Chesapeake localities. — (a) Previous record: Mouth of Chesapeake Bay. ( b ) Specimens in 
collection: Old Point Comfort, Va., beam trawl, depth 73 to 84 feet, December 2, 1915, April 2, 1921 ; 
Lynnhaven Roads, pound net, April 6, 1922, November 28, 1921; Willoughby Spit, Va., November 
15, 1922; also seen at several other points in the'southern sections of the bay. 
