THE LAKE STURGEON. 661 



THE LAKE STURGEON ACIPENSEB RUBICUNDUS. 



The moat satisfactory investigation of the Lake Sturgeon is that published by Milner in Part 

 II of the Report of the United States Fish Commission, pages 67 to 75. This species inhabits the 

 Great Lakes and the waters lying to the northward, and the rivers of the Mississippi Valley. It 

 is especially abundant in the Upper Lakes. It is a smaller species than the Atlantic Sturgeon, 

 and has a greater number of plates or scutes upon the sides according to Jordan, about thirty- 

 four instead of twenty-eight. 



SPAWNING HABITS. Milner records the following observations upon the general habits and 

 history of the Lake Sturgeon : 



"The spawning season of the Sturgeon in the more southern lakes occurs in the month of 

 June; in Lake Superior it is a little later. Early in June, in the southern end of Lake Michigan, 

 they begin to congregate near the shores and at the mouths of the rivers, the Kalamazoo River, 

 emptying at Saugatuck, Michigan, being a favorite spawning ground. They may be seen in the 

 evening in this river leaping from the surface, throwing their bulky forms entirely out of the 

 water. At Pier Cove, Michigan, on the llth of June, 1871, schools of Sturgeons were at the edge 

 of the shore in a few feet of water, and men from the vicinity were in the habit of wading out and 

 drawing them ashore with gaff-hooks. Eighteen were taken in this way the morning we visited 

 the locality. They were said to be found in the vicinity every year about this season, remaining 

 about a fortnight. It is likely they were spawning at the time. Whether the shore of the Lakes, 

 where the waves would disturb the eggs in every storm, is a natural spawning ground is a ques- 

 tion. They may have been late arrivals seeking the mouth of the Kalamazoo River, a few miles to 

 the north of which they are said to ascend to the first dam, many miles inland. 



"Mr. J. G. Portman, of Benton Harbor, successful as a fish-culturist, has seen the Sturgeon at 

 this season lying in numbers on a shallow clay ledge at the edge of a stream, several of them lying 

 flat on their backs, with their bellies upward, rolling and splashing in shallow water with apparent 

 enjoyment. Two or three that were taken with spears were opened and the stomachs examined 

 and found to contain some of the sturgeon spawn. At the mouth of Calumet River, South Chicago, 

 Illinois, July 1 of the year just referred to, a large lift of Sturgeon were brought ashore, looking 

 flaccid and emaciated, and but one specimen out of over twenty individuals contained spawn. In 

 the vicinity of Bayfield, Wisconsin, on Lake Superior, they were seen late in the month of July with 

 the ovaries full of spawn, and the milt of the male fishes large, making it probable that the time of 

 spawning was later in colder water than in warm. 



"SiZE. The Sturgeon of this species attains the largest size of any fish of the Lakes. They 

 are taken only within comparatively shoal waters and in some of the bays, and a?nong the islands 

 they are very abundant. The largest specimen it has been my fortune to see did not quite attain 

 the length of six feet, though there are traditions in localities on the Lakes of nine-foot Sturgeons; 

 the average of the mature ones taken is less than five feet. 



"Their food consists almost entirely of the shell-fish of the Lakes, principally gasteropods, the 

 thinner-shelled kinds of the genera Physa, Planorbis, and Valvata being found broken in the 

 stomachs, while Limncca and Melnnlho remain whole. A few eggs of fishes have been found at 

 different times, but examination of stomachs during the spawning season of some of the most 

 numerous fishes did not prove them to be very extensive spawn-eaters. 



"ENEMIES. In Green Bay the fishermen set their pounds for fall fishing about the 10th of 

 September. The Sturgeon are in abundance, and the nets often contain a hundred or more. This 

 is said to continue until about the middle of October, when they diminish in number and the white- 



