282 ALLEN! POLYODON SPATHULA 



been almost at a standstill or a rather strong current. There is 

 no ground whatever for believing that these little Polyodon were 

 hatched and reared in Minor Slough. 



While this seining was being done a violent thunder storm was 

 in progress so that little time was spent in examination of these 

 most interesting specimens; they were immediately thrown into 

 a fixing fluid. It was noted, however, that their bill or paddle 

 constituted about one-half of their total length, and that their 

 bodies were almost transparent. 



Notwithstanding that this slough and other overflow lakes and 

 small tributary streams were afterward frequently seined with a 

 fine-meshed seine, and the river bars were seined with both fine- 

 and coarse-meshed seines, during both day and night, no other 

 young Polyodon were found until late in August or early Septem- 

 ber, when a large number were obtained thru seining, at night or 

 early morning, the mud and sand bars of the Ohio River opposite 

 Cairo on the Kentucky side. Singular to say, they were never 

 obtained in this manner during the day time. Apparently they 

 never leave the channel except at night to feed in the mud and 

 sand bars. These small fish were all obtained by the use of a 

 very long coarse-meshed seine. It is possible that if a sufficiently 

 long fine-meshed seine could have been operated on the river bars 

 at night, or dragged on the bottom of the channel during the day, 

 still younger stages would have been obtained. 



My experience with Polyodon leads me to believe that it is 

 primarily a deep-channel fish, that the eggs are laid and the young 

 are reared in the deep channel rather than in the shallow water of 

 the river, or in overflow lakes, or in small tributary streams; that 

 the young do not leave the main channel to feed in the mud bars 

 of the river or the sloughs until they have attained a length of 

 3 or 4 inches. About Cairo, Illinois the spawning season occurs 

 during the month of March, and only specimens from 15 to 20 

 pounds and up are sexually mature. Fish of this size are rarely, 

 if ever, taken in seining the river bars, but they can be had in small 

 numbers from fishermen operating hoop-nets in the Missouri 

 channel of the Mississippi south of Bird's Point. 



