14 HABITS OF THE BLACK CRAPPIE. 
fishing from a drifting rowboat with three hooks baited with min- 
nows and whitebait, caught 52 Pomowis sparoides, 1 Lepomis incisor, 
1 Lepisosteus osseus, in an area about 100 meters wide and 400 meters 
long, where the depth was 2 to 3 meters. At the same time only 
four crappies were caught with similar equipment 300 meters west. 
At other times the catches on those areas under similar circumstances 
never exceeded five crappies. On May 20, 1916, four male crappies 
were caught in a few minutes; they were all on the same side of the 
gill net, within an area of 4 feet square. Apparently they had been 
swimming along together. There were other occasions when crappies 
seemingly swam in schools, but there were also many times when 
they were caught singly. 
V. ENEMIES AND PARASITES. 
Compared with the perch, the crappie is relatively free from para- 
sites (Pearse and Achtenberg, forthcoming report). Though the 
perch in the Wisconsin lakes are heavily infested with proteocephalid 
larvee, distomes, nematodes, and acanthocephalans, the crappies are 
generally free from such parasites. Of the 276 crappies examined, 
only 11 carried parasites, and the occurrence of all is given in the 
following list: 
September 17, 1915; southeast corner of Lake Monona; crappie, 116 milli- 
meters long; nematodes in the intestine. 
October 27, 1915; Lake Wingra; two crappies, 48 and 388 millimeters long, 
respectively, both with nematodes in the intestine. 
May 138, 1916; Lake Wingra ; ripe female, 146 millimeters long with nematodes 
in intestine; young male, 112 millimeters long with cysts along whole length of 
intestinal wall. 
May 13, 1916; University Bay, in Lake Mendota; male, 200 millimeters long; 
a trematode in intestine. 
June 10, 1916; Lake Wingra; female, 160 millimeters long; cysts along in- 
testine. 
July 3, 1916; Lake Wingra; immature male, 112 millimeters long; tapeworm 
cysts on intestine. ; 
August 20, 1916; male, 170 millimeters long; nematodes in intestine. 
November 26, 1916; crappie, 44 millimeters long; proteocephalid * tapeworm 
eysts along intestine. 
January 1, 1917; open stream west of University of Wisconsin; crappie, 58.5 
millimeters long, a leech, Piscola punctulata attached to body. 
Summary: Intestinal nematodes, 5; intestinal trematode, 1; cysts in peri- 
toneum along intestine, 4; leech, 1. 
VI. GENERAL DISCUSSION. 
Though perch exceed crappies in numbers in Lake Wingra, they 
do not attain maximum growth.? The crappies are large and, in 
proportion to their greater sizes, abundant. Evidently the small, 
shallow lake is not a favorable habitat for the perch, but is satisfac- 
tory for the crappie. The differences between the two species may 
be summarized by stating that: (1) The perch feeds more by day 
and eats less of pelagic crustaceans than the crappie; (2) the perch 

«Thanks are due to Dr. George R. La Rue, who identified these. _ ] 
vb The complete data for line and gill net catches have been given in a previous paper 
by Pearse and Achtenberg, which is expected to be published shortly by this Bureau. 
Judged by the catch per hour on hooks baited with minnows, the larger fishes are pres- 
ent in Lake Wingra in the following ratios: Perch, 145; crappie, 94; bluegill sunfish, 
79: largemouth black bass, 3; pumpkinseed, 3; gar, 1. From the catch per hour in gill 
nets the following ratios were obtained: Perch, 307; bream, 32; crappie, 20; bluegill 
sunfish, 17; dogfish, 16; pumpkinseed, 12; pickerel, 9; carp, 7; smallmouth black bass, 
5; largemouth black bass, 4; black bullhead, 2; gar, 1. 
