244 ZOOLOGY 



foundland to Florida. 1 Next to the Pacific salmon and 

 cod, it is commercially our most important fish, for the 

 catch of Atlantic shad for 1896 exceeded one and a half 

 million dollars. The Pacific coast has been successfully 

 stocked with shad from the Atlantic. The Atlantic shad, 

 like the salmon, migrate up streams to deposit their eggs. 

 The alewives have the same habit. The herring, on the 

 contrary, spawn in the sea. As the common name, allied 

 to the German Heer, an army, implies, they travel in great 

 schools. The menhaden, which also occur in great schools, 

 have of late years been destroyed in vast numbers to make 

 fertilizers. 



The eels are easily distinguished by their serpentine 

 form, the absence of ventral fins, the long dorsal fin, and 

 the rudimentary or absent scales. These fish occur all 

 along our coast and ascend streams. During the day they 

 lie hidden in mud and at night they feed, their principal 

 prey being small aquatic animals, the young of other fish, 

 and shrimps and crayfishes during the moulting period. 

 On account of the narrowness of the gill-opening, they 

 may live for some time out of water in a moist place. The 

 reproduction of the eel was long a mystery. All sorts of 

 creatures have in past times been supposed to produce 

 them, ranging from the gods to water-beetles. They have 

 even been thought to be generated from slime. We now 

 know, however, that there are both male and female indi- 

 viduals ; that the males live chiefly, but not exclusively, in 

 the sea ; that reproduction occurs chiefly in the sea ; and 

 that the young females come from the sea and pass up the 

 rivers during the spring. 



The pipe-fishes and their allies (Lophobranchii) include 



Fig. 227. 



