3 1 8 Memoir Sears Foundation for Marine Research 



Evidence has been set forth that chrysochloris reproduced in Lake Pepin after 

 the closing of Keokuk Dam, an almost complete barrier to them. Dr. Coker said that 

 without question there was a decided decline in the number of "River Herring" in this 

 Lake during the three years immediately following the dam's construction, but some 

 commercial catches there in 1926, 12 years after the dam was closed, convinced him 

 that these fish were not rare; and several commercial fishermen stated that "the 

 herring were coming back." On the basis of Dr. Coker's observations, it seems 

 proper to conclude that P. chrysochloris, although migratory, does not need to have 

 access to salt water to reproduce, and the species surely is not strictly anadromous. 

 The presence of immature examples in a collection from brackish water as well as from 

 the upper Mississippi also may be of some significance. 



Food. Skipjack Herring are carnivorous (55: 49); the young feed on insects, the 

 adults on fish. Coker stated that, of about 150 examples examined for food: 



Approximately one-third were empty; a little more than one-third contained fish, chiefly minnows, with some 

 mooneyes, gizzard shad, and other fish not determinable; and less than one-third contained insects and larvae, 

 principally May flies, with some caddis flies and others. 



Habits. These are more active fish than most other clupeoids ; they frequent rivers 

 with swift currents and often leap from the water, a habit from which they have derived 

 the name Skipjack. They leap in part for sport and in part for the pursuit of prey (J5: 

 49). Coker remarked that they have, "a striking habit of leaping from the surface 

 when feeding upon schools of minnows or in mere play." 



Parasites. We know only that the larvae (glochidia) of the freshwater mussel Fus- 

 conaia ehena are parasitic on the Skipjack (see below). 



Commercial Importance. The value of this species as a foodfish is negligible, for 

 these fish are bony and not especially well flavored. No catches have been listed in the 

 statistical reports of the U. S. government. However, they represent a very distinct 

 economic asset as a host for the larvae of Fusconaia ehena, which has been regarded 

 as the most valuable of all the pearly mussels of the Mississippi Basin because of its 

 abundance in all the larger waters of strong current and because it yields a shell of the 

 best quality for buttons {2'j: 166). 



Range. Skipjack Herring range in the Gulf of Mexico from Pensacola, Florida, 

 to Corpus Christi, Texas, and sometimes out into the Gulf, as off Breton Island, 

 Louisiana. They also inhabit larger streams, occasionally lakes, or even borrow pits, of 

 the Gulf drainage. They commonly range as far north in the Mississippi River as Lake 

 Pepin, and occasionally to Fort Snelling, Minnesota, to Hudson, Wisconsin, and in 

 the Ohio River to Pittsburgh, Pennsylvania. Apparently they are landlocked above 

 Keokuk Dam, Iowa. Although Smith (jJ^: 214) said that they were abundant in Lake 

 Erie, and Jordan and Evermann (72, 1896: 425) as well as several others have stated 

 that they reached Lake Michigan and Lake Erie through canals, Hubbs and Lagler 

 (62: 27, ftn.) do not admit them to their list of fishes of the Great Lakes and tributary 

 waters. The species apparently is most common in swift currents of large streams. 



