Fishes of the Western North Atlantic 3 9 



age. The growth rate of the two species, however, is very similar in early life, which 

 suggests that the subsequent divergence is due to more rapid growth by oxyrhynchus 

 while at sea. 



Spawning. Males may mature when they are only about 20 inches TL, and most of 

 them do so by the time they pass 21 inches; most of the females mature at about 24 

 inches. The ripe eggs are dark brown. Their number is not known. Spawning takes place 

 in rivers early in the spring. For Hudson River fish, Greeley (j5: 90) stated that: 



The spawning season evidently included late April during 1936. Several fish approaching spawning 

 condition were examined from RhineclifF during early April. A female, weighing five pounds, from Highland 

 April 21 contained eggs which appeared ripe, while a three pound male taken at the same time was spent. Roe 

 fish from Highland, May i, were spent (2 pounds, 13V2 ounces; 5 pounds, 8 ounces). Several others, also 

 taken during early May had spawned. 



General Habits. On account of its small size, A. brevirostris has attracted little atten- 

 tion except when taken in nets in fresh, brackish, or salt water. It is found most often 

 in tidal rivers. But the place of capture of Gulf of Maine specimens shows that some 

 certainly go out into the open sea and wander for some distance from the parent 

 stream. 



Food. Studies of stomach contents from Hudson River specimens showed that A. 

 brevirostris feeds upon the bottom, eating small animals and plants intermingled with 

 mud (J2: 14 1 -144, table 4). The organisms consumed were sludgeworms, chironomid 

 larvae, small crustaceans, etc., such as are found in the stomachs of young Atlantic 

 Sturgeon (p. 52). 



Abundance and Relation to Man. Because of its scarcity and small size, A. brevirostris 

 is of slight interest to commercial fishermen, hence there is little information about 

 its abundance. 



Ryder i^^: 232), writing of the fishery for oxyrhynchus in the Delaware River, 

 stated, "It was my good fortune to secure no less than five specimens of the A. brevirostris 

 of LeSueur, which has, so far as I can learn, not been certainly recognized since that 

 Naturalist's time," and our own Study Material (p. 36) marks it as at least not uncom- 

 mon in the Hudson today. But while LeSueur in 1 8 1 1 stated that the Shortnose 

 Sturgeon is "more sought after and commands a higher price than the large common 

 species" in the Delaware River {j^: 383-394), it is of virtually no economic importance 

 at present due to its small size and apparent scarcity. Its flesh, however, is of good 

 quality, and its eggs are suitable for caviar, but they are not very numerous. A few 

 fishermen prior to 1937 set gill nets for brevirostris in the Hudson River just before 

 the yearly run of American shad {Alosa sapidissimd). Some have also been taken in the 

 Hudson River with hook-and-line by anglers. 



Range. Atlantic seaboard of North America, from New Brunswick, Canada (.^7 : 

 504, and later comments), to Florida, mostly in rivers, Including the Connecticut, Hud- 

 son, Delaware, and Potomac. This range is based upon records for_a period of years, 

 and the species may now occupy a more restricted area. 



Until recently the southernmost definite record was for Charleston, South Carolina 



