Biological Survey — Erie-Niagara Watershed 201 



Plate 1. — Pictorial representation of the life cycle of the bass tapeworm, 

 Proteocephalus amhloplitis (Leidy), magnified to show the early stages. 



(1) Adult bass tapeworm (P. ambloplitis) from intestine. The mature 

 proglottids (segments) occur at the posterior end. These break off and 

 are passsed with the feces. (Drawing natural size.) 



(2) Mature segments falling to the bottom, liberating thousands of eggs 

 upon contact with the water. 



(3) FIRST INTERMEDIATE HOSTS. Five (?) species of Cyclops and 

 Hyalella knickerbockeri eat the eggs from the bottom. The eggs disintegrate 

 after being in the water 36 to 48 hours. The jaws and digestive juices of 

 the copepods liberate the larva of the tapeworm which bores through into 

 the body cavity. (Drawing of copepods magnified disproportionately to bring 

 out details.) 



(4) SECOND INTERMEDIATE HOSTS. Young large-mouthed and small- 

 mouthed black bass, rock bass, pumpkinseed sunfish, yellow perch, pickerel and 

 the top minnow {Fundulus diaphanus) feed on the first intermediate hosts. 

 The larval tapeworm bores through the digestive tract and into the body 

 cavity; it encysts. 



(5) DEFINITIVE HOSTS. Large-mouthed and small-mouthed black bass and 

 rock bass harbor the adult tapeworm which is secured by eating the second 

 intermediate host thus bringing the larval tapeworm back to the digestive tract 

 where proglottid formation takes place and the cycle is repeated. 



