FISHES OF CHESAPEAKE BAY 
101 
Comparative statistics of the shad product of Maryland and Virginia for various years from 
1880 to 1921 
Years 
Pounds 
Value 
Years 
Pounds 
Value 
1880 __ 
6, 946, 379 
7, 855, 946 
11,924,908 
14, 393, 693 
12, 723,115 
16, 712, 018 
17, 329, 037 
$275, 422 
319, 223 
498, 289 
471, 806 
418, 969 
473, 606 
463, 813 
1901 
10, 083, 393 
10, 332, 148 
11,251,000 
9, 282, 888 
6, 168, 669 
9, 161, 001 
8, 716, 250 
$486, 805 
599, 397 
733, 000 
761, 205 
849, 527 
1, 500, 323 
1, 546, 990 
1887 
1904 
1888 
1908 
1890 _ . 
1909... 
1891 . 
1915 
1S90 
1920 . 
1897 
1921 
Note. — The catch of shad in these States, outside of the Chesapeake. Bay, is included for some years but is practically 
negligible. 
27. Genus OPISTHONEMA Gill. Thread herring 
Body elongate, compressed; the abdomen strongly compressed, armed with about 33 prominent 
scutes; lower jaw projecting; upper jaw somewhat emarginate; dorsal inserted in advance of ventrals 
the last ray greatly produced, filamentous; vertebrse about 42. A single species of this genus is 
known from the Atlantic coast of America. 
37. Opisthonema oglinum (LeSueur). “Hairy-back”; Thread herring; “Shad herring.” 
Megalops oglina LeSueur, Journ., Ac. Nat. Sci., Phila., I, 1817, p. 359; Newport, R. I. 
Opisthonema thrissa Uhler and Lugger, 1876, ed. I, p. 158; ed. II, p. 134. 
Opisthonema oglinum Bean, 1891, p. 93; Jordan and Evermann, 1896-1900, p. 432. 
Head 3 to 4.3; depth 2.0 to 2.9; D. 18 or 19; A. 22 to 24; scales 70 to 77. Body moderately 
deep, compressed; abdomen compressed, with sharp scutes on ventral edge; head rather small; 
snout moderate, 3.7 to 4.2 in head; eye with adipose eyelid, 3.6 to 4.2; interorbital 3.8 to 4.2; mouth 
nearly terminal; the lower jaw projecting a little; maxillary reaching anterior margin of pupil, 2.4 
to 2.6 in head; teeth wanting in the jaws, small ones present on median line of tongue; gill rakers 
long and slender, numerous, 70 to 77 on the lower limb of the first arch; scales rather large, cycloid, 
loosely adherent; ventral scutes 17 or 18+15 or 16; lateral line wanting; dorsal fin rather small, 
somewhat elevated anteriorly, the last ray greatly produced in the adult, reaching nearly or quite 
to base of caudal, origin of dorsal in advance of ventrals and much nearer tip of snout than base of 
caudal; caudal fin forked, the lower lobe slightly the longer; anal fin long and very low, its origin 
nearer base of caudal than base of ventrals; ventral fin small, inserted under middle of base of dorsal j 
pectoral fins moderate, inserted a little in advance of margin of opercle, 1.2 to 1.3 in head. 
Color in alcohol, bluish gray with a metallic luster above; lower part of sides silvery; tip of snout 
black; a more or less distinct dark shoulder spot; indefinite dark lines along the rows of scales on 
the back; fins chiefly plain translucent, the dorsal and caudal with black tips. 
No small individuals were taken. Eight specimens of adult fish, ranging from 198 to 230 
millimeters (7% to 9 inches) in length, were preserved. This species is readily recognized (except 
the very young) by the greatly produced posterior ray of the dorsal fin, which reaches nearly or 
quite to the base of the caudal fin. It is from this long, threadlike ray that the fish has received the 
name “hairy-back” and “thread herring.” 
The food of this fish appears to consist largely, if not wholly, of small organisms, which it 
strains from the water by means of its long gill rakers. Doctor Linton examined the contents of 
three stomachs and found copepods exclusively. 
The hairy-back is essentially a tropical fish and as a rule it is not abundant in Chesapeake Bay. 
Its spawning habits are almost wholly unknown. This herring reaches a size of about 12 inches, 
but its flesh is bony and of little value as food. Its commercial importance among the fishes of 
Chesapeake Bay is slight, as it is rarely used for food. However, it is utilized along with the men- 
haden in the manufacture of fertilizer and oil when taken in sufficient quantities. The fish usually 
makes its appearance about the middle of May, and it leaves the bay during October. It is taken 
in comparatively small quantities in pound nets throughout the summer in the southern parts of 
the bay, the catch rarely exceeding 100 pounds a day for one set of nets. The hairy-back appears 
