388 
BULLETIN OF THE BUREAU OF FISHERIES. 
their numbers varied from 6,800 (opposite Root River) to 35,660 per cubic meter 
at Reads Landing in the outlet of Lake Pepin (stations 124 to 135, September 10, 
12). In the main channel of the river, just below Lake Pepin, the number of 
Copepoda was even greater, reaching 44,000 to 46,000 per cubic meter (stations 
101, 104, August 30). 
Table 19. — Number of Copepoda and Cladocera in the Mississippi River between Hastings, Minn., and 
Alexandria, Mo. 
Serial 
number 
of station 
Number 
of Co- 
pepoda 
per cubic 
meter. 
Number 
of Cla- 
docera 
per cubic 
meter. 
Number 
of Cla- 
docera 
per cubic 
meter. 
Near Hastings 
Near Prescott 
Diamond Bluff 
Near Red Wing 
One mile above head of Lake Pepin: 
Left bank 
Midstream 
Right bank 
Above mouth of Chippewa River below 
Lake Pepin, main channel: 
Right bank 
Midstream 
Left bank 
Reads Landing, main channel: 
Right bank 
Midstream 
Left bank 
One mile above Wabasha, main channel 
Beef Slough 
Opposite mouth of Zumbro River 
Between W inona and Homer, main channel. 
One mile above La Crosse, main channel 
Slough near light No. 98 
Four miles above La Crosse, right bank 
Opposite mouth of Root River, main 
channel 
Between De Soto and Lansing, main channel. 
Three miles above Prairie du Chien, main 
channel 
Prairie du Chien, east channel: 
Midstream 
Left bank 
McGregor, main channel 
Opposite mouth of Wisconsin River, main 
channel 
One mile below Cassville, main channel 
One-half mile below Bellevue, main channel 
Six miles above Clinton, main channel 
Three miles below Clinton, main channel. . . 
Rock Island Rapids 
One mile below mouth of Rock River, main 
channel 
Fairport: 
Main channel 
Andalusia slough 
Do 
Main channel 
Below the dike 
New Boston: 
Main channel 
Sturgeon Bay 
Midstream 
One mile below mouth of Edwards River: 
Midstream 
Main channel 
Two miles below Burlington, main channel . 
Alexandria, main channel 
Sept. 1 
...do 
...do 
...do 
Aug. 29 
...do 
...do 
Aug. 30 
...do 
...do 
...do. 
Aug. 
46,223 
21,550 
125, 660 
44,010 
15, 980 
1,300 
Aug. 15 
...do 
19, 253 
20,970 
Aug. 12 
Aug."ii 
5,467 
7 
July 12 
July 11 
Aug. 9 
July 13 
...do 
..do 
...do 
Sept. 10 
...do 
.. .do 
Sept. 12 
Sept. 13 
...do 
Segt. 14 
...do 
. .do. 
Sept. 
Sept. 
. Se lo t :. 20 . 
Sept. 23 
1,840 
14, 581 
20, 340 
16,290 
15, 520 
27,047 
29,000 
The increase in the crustacean population was due mainly to an increase of 
Copepoda, the Cladocera being many times less abundant. A peculiar gathering 
of Copepods was observed at the left bank of the river near the Chippewa Delta 
(Table 19, station 106) , where in shallow stagnant water the number reached 125,660 
per cubic meter. No Water fleas were found at this station, and the swarm of cope- 
pods consisted exclusively of Diaptomus and Cyclops. 
