148 The Apodes, or Eel-like Fishes 



cephali, pass through a band-shaped or leptocephalous stage, 

 as is the case with Albula and other Isospondyli. In the con- 

 tinued growth the body becomes firmer, and at the same time 



FIG. 102. Larva of Common Eel, Anguilla chmsypa (Rafinesque) , called Lcpto- 

 cephalus grassii. (After Eigenmann.) 



much shorter and thicker, gradually assuming the normal form 

 of the species in question. 



In a recent paper Dr. Carl H. Eigenmann has very fully 

 reviewed the life-history of the eel. The common species live 

 in fresh waters, migrating to the sea in the winter. They 

 deposit in deep water minute eggs that float at the surface. 

 The next year they develop into the band-shaped larva. The 

 young eels enter the streams two years after their parents drop 

 down to the sea. It is doubtful whether eels breed in fresh 

 water. The male eel is much smaller than the female. 



The eel is an excellent food-fish, the flesh being tender and 

 oily, of agreeable flavor, better than that of any of its rela- 

 tives. Eels often reach a large size, old individuals of five or 

 six feet in length being sometimes taken. 



Species of Eels. The different species are very closely related. 

 Not more than four or five of them are sharply defined, and 

 these mostly in the South Seas and in the East Indies. The 

 three abundant species of the north temperate zone, Anguilla 

 anguilla of Europe, Anguilla chrisypa of the eastern United States, 

 and Anguilla japonica of Japan, are scarcely distinguishable. In 

 color, size, form, and value as food they are all alike. 



Fossil species referred to the Anguillida are known from 

 the early Tertiary. Anguilla leptoptera occurs in the Eocene 

 of Monte Bolea, and Anguilla elegans in the Miocene of (Eningen 

 in Baden. Other fossil eels seem to belong to the Nettasto- 

 mida and Myridce. 



Pug-nosed Eels. Allied to the true eel is the pug-nosed eel, 

 Simenchelys parasiticus, constituting the family of Simen- 

 chelyida. This species is scaled like a true eel, has a short, 



