FISHES OF NEIW YORK 531 



dering eggs was introduced into a wide aquarium fungus also' 

 ittacked the eggs as before but the results were somewhat 

 nore favorable. With the water at 58 to 60 F. the eggs; 

 latched out in 6 days. 



The white perch congregates in large schools and is one of 

 ;he freest biters among fishes. The shrimp is one of the best 

 jaits, though worms, sturgeon eggs, minnows and strips of cut 

 ish with silvery skin are equally effective. Dr Abbott has 

 vuown as many as 20 dozen to be taken with a line in a few 

 lours, and Spangler mentions catches of six or seven hundred 

 n a day by two rods, the fish ranging in weight from f to 1^ 

 )Ounds. 



Eugene Smith, on several occasions, found a long, green, 

 )rackish-water alga (Enteromorpha) in stomachs "f 

 vhite perch, indicating that they sometimes eat vegetable mat- 

 er, though perhaps only for the minute organisms found 

 ipon it. 



In captivity the fish is ver^^ susceptible to fungus attacks, but 

 he parasite is readily killed by changing the water supply 

 rom salt to fresh, or vice versa. 



Genus polyprion Cuvier 

 Body robust, moderately elevated, not much compressed, cov- 

 'ved with small, firm, ctenoid scales which extend on the bases 

 >f the vertical fins. Lateral line complete, partly concealed 

 mder adjacent scales, the tubes covering the whole length of 

 he scale. Mouth large, the lower jaw projecting; maxillary 

 vith supplemental bone. Teeth in broad, villiform bands on 

 aws, vomer, palatines, and tongue; no canine teeth. Head 

 icaly. Preopercle serrate; orbital region with spinous projec- 

 ions; opercle with a strong spine and with a strong, rough, 

 )ony longitudinal ridge; gill membranes separate; gill rakers 

 ong, few. Dorsal fin continuous, low, with 11 strong spines 

 ind 11 or 12 rays, the spinous portion longest; caudal rounded; 

 mal short, with three spines, the third the longest; ventrals 

 arge, inserted below, little behind pectoral; caudal rounded or 

 runcate; pectorals short, unsymmetrical, of 18 or 19 rays, the 



