Lake Maxlnkuckee, Physical and Biological Survey 367 



canadensis) and any mass of this vegetation that might be raked 

 out was sure to contain one or more mud minnows. They were 

 also common in and about the Armstrong pond; they sometimes 

 would be found in the mud at the bottom of cow tracks some dis- 

 tance from water. 



These are oviparous fishes, the sexes similar, small in size, 

 carnivorous in 'their habits, feeding upon small crustaceans, insect 

 larvae and the like. One specimen examined contained an Asellus, 

 and they are also said to feed to a large extent on the minute 

 duckweed, Wolffia. They are extremely tenacious of life and will 

 live a long time in the mud in the bottom of a pool which has en- 

 tirely dried up. When dug out of the mud and placed in water 

 they usually seem normally vigorous and active. They can be kept 

 indefinitely in minnow buckets or old rain barrels without change 

 of water. 



They are frequently used by anglers as bait for pickerel and 

 wall-eyed pike, but they are chiefly valuable on account of their 

 great tenacity of life. Anglers who have tried this bait at Lake 

 Maxinkuckee, however, have not found them a very killing lure. 



The Mud Minnow is familiar to almost everyone who ever goes 

 seining for minnows ; but, as it bears a superficial resemblance to the 

 dogfish, Amia calva, the young of which are rarely seen, they are 

 usually supposed to be young dogfish. The interesting remarks 

 by Charles Halleck regarding the young of the dogfish as bait 

 doubtless refer to the Mud Minnow. 



Various anglers at Lake Maxinkuckee to whom specimens of 

 the Mud Minnow were shown pronounced them young dogfish. 

 The two species are not at all related, however, and may be easily 

 distinguished by the much larger dorsal fin of the dogfish, in which 

 there are about 48 rays while in the Mud Minnow there are but 15 

 dorsal rays. 



Specimens of Mud Minnow examined on April 9, appeared to be 

 nearly ripe, and they probably spawn about the middle of April. 

 The eggs are 1/20 of an inch in diameter and varied from about 

 425 to 450 per individual. 



Head 3.5 to 3.75 in length; depth 4.5 to 4.75; eye 5.5 to 6 in 

 head; snout 4.5 to 5; dorsal 15; anal 10; pectoral 14; ventral 6; 

 scales about 37,-13; branchiostegals 6. Body oblong, somewhat 

 compressed, covered with rather large, cycloid scales; head rather 

 short, bluntly conic, little depressed; caudal peduncle deep, com- 

 pressed; eye moderate, high up; mouth rather large, slightly ob- 

 lique, lower jaw projecting, maxillary reaching vertical of an- 

 terior part of pupil ; cheeks, opercles and top of head scaled ; dor- 



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