FISHES OF CHESAPEAKE BAY 
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length. On the large example at hand the dark spots are much deeper than long; in the smaller 
specimens they are roundish. In specimens 5 inches and less in length these spots are indistinct 
or absent. The lateral line is not always complete and at times it is wanting. This character, 
however, does not appear to be correlated with age, as has been supposed. The spotted sucker 
usually is readily distinguished from all other suckers by the presence of dark spots on the scales, 
forming dark longitudinal lines. It also differs from related suckers in having the outer margin 
of the dorsal fin concave, and in the reduced number of longitudinal rows of scales on sides between 
the dorsal and ventral fins. This fish is known to reach a length of 18 inches. 
The striped sucker evidently is rare in the Chesapeake Bay vicinity, as we are unable to find 
a record of its previous capture and the specimens in hand are the only ones seen in the field by the 
collectors. The species appears to be mainly a creek and small-river fish. However, the large 
specimen at hand was caught in brackish water in the narrows off Spesutie Island. “From the 
little that is known of its food we may surmise that it lives largely on mollusks and insect larva*.’’ 
(Forbes and Richardson, 1908, p. 83.) We are unable to find anything in the literature on the 
spawning and breeding habits of this sucker, and it is probable that nothing distinctive is known 
about it. 
Habitat . — “Great Lakes region to North Carolina (Cape Fear River) and west to Texas; 
rather common westward.” (Jordan and Evermann, 1896-1900.) 
Chesapeake localities. — (a) Previous records: None. ( b ) Specimens in collection: From 
Spesutie Island near Havre de Grace, Md., 300-foot seine, Nov. 12, 1921, salinity, 1.53 per mille; 
Susquehanna River, Havre de Grace, Md., 30-foot seine, Aug. 27, 1921, water fresh. 
35. Genus CATOSTOMUS LeSueur. Fine-scaled suckers 
Head somewhat elongate; mouth inferior, the upper lip thick, protractile, papillose, lower 
lip greatly developed, incised behind, forming two lobes; scales small, 50 to 115 in a lateral series; 
lateral line well developed, air bladder with two chambers; dorsal fin with 14 to 19 rays. 
46. Catostomus commersonii (Lacdpede). Common sucker; White sucker; Mud sucker; Black 
mullet. 
Cyprinus commersonii Laefipede, Hist. Nat. Poiss., V, 1803, p. 502; locality unknown. 
Catostomus communis Uhler and Lugger, 1876, ed. I, p. 162; ed. II, p. 138. 
Catostomus teres Bean, 1883, p. 367. 
Catostomus commersonii Jordan and Evermann, 1896-1800, p. 178, PI. XXXIV, fig. 83. 
Head 4.08 to 4.35; depth 4.45 to 4.82; D. 14 or 15; A. 8; scales 63 to 67. Body elongate, little 
compressed; head quadrate, a little deeper than broad; snout conical, 1.9 to 2.15 in head; eye 4.4 
to 6; interorbital 2.4 to 2.55; mouth inferior; lips papillose, the lower one broader than the upper; 
scales rather small, reduced in size anteriorly, about 20 longitudinal rows on sides between the 
dorsal and ventral fins; lateral line complete; dorsal fin about as long as high, the outer margin 
nearly straight, its origin a little nearer tip of snout than base of caudal; caudal fin moderately 
forked; anal fin much shorter, but higher than the dorsal, its origin about equidistant from base of 
ventrals and base of caudal; ventral fins short, inserted under middle of base of dorsal; pectoral low, 
1.4 in head. 
Color bluish-green above, pale below; dorsal and caudal fins more or less dusky, the other fins 
more or less orange. Spring males with a more or less distinct rosy lateral band. Young darker 
gray, mottled with black; the blotches sometimes more or less confluent and occasionally forming a 
lateral band. 
The Chesapeake collection contains three specimens, respectively, 215, 222, and 235 millimeters 
(8)^!, 8%, and 9J4 inches) in length, which were taken in slightly brackish water. These three 
and some smaller specimens from fresh water form the basis for the above description. This sucker 
is distinguished from all other suckers of the vicinity by the small scales, of which there are from 
63 to 67 in a lateral series and about 20 longitudinal rows on the side between the dorsal and ventral 
fins. The scales are reduced in size anteriorly and appear crowded. 
The alimentary canal is long and somewhat convoluted, without a sharp differentiation between 
the stomach and intestine. A specimen inches in length had an alimentary canal 17 inches 
long. The food of this sucker, according to Smith (1907, p. 73), consists of insects, mollusks, 
