FISHES OF THE GULF OF MAINE 



151 



Eel Anguilla rostrata (LeSueur) 1817 



American eel; Silver eel; Fresh-water eel; 

 Elver (young) 



Jordan and Evermann 1896-1900, p. 348, A. ehrysypa 

 Rafinesque 1817. 



Description. — In the common American eel the 

 dorsal fin originates far behind the pectorals, 

 this character is enou^j to distinguish it from the 

 conger, from which it also differs in that the lower 

 jaw projects beyond the tipper or at least equals 

 it in length, and its eyes are small and round. 

 Furthermore, it develops scales as it grows, though 

 these are so small that they might be overlooked. 

 The eel, however, has a pointed snout, like the 

 conger, a large mouth gaping back as far as the 

 middle of the eye or past it; and its gill slits are 

 set vertically on the sides of the neck, their upper 

 corners abreast of the center of the base of the 

 pectoral fin. It is very closely related to the 

 European eel (Anguilla vulgaris), but has fewer 

 vertebrae (average about 107 as compared with 

 about 114 or 115 in the European species). 



Color. — The colors of eels vary widely with the 

 bottom on which they live. As a rule they are 

 dark muddy brown or olive-brown above, more 

 or less tinged with yellow on the sides; the lower 



surface paler brown and yellower, with dirty yel- 

 lowish-white belly. It is common knowledge 

 that eels are dark if living on dark mud but much 

 paler on pale sand. And Parker M has found that 

 they can change from pale to dark in about 1% 

 hours and from dark to pale in a little more than 

 3 hours, if moved from a white background to a 

 black or vice versa, under a strong light. 



Size. — Eels are said to grow to 4 feet in length 

 and to 16K pounds in weight. Full-grown females 

 average only about 2 to 3% feet, however, and 

 males are smaller. Any eel more than 18 inches 

 long would probably be a female, and one more 

 than 24 inches in length would certainly be one. 

 The smallest mature males are about 11 to 12 

 inches long, females about 18 inches. 



Habits. — The life history of the eel remained a 

 mystery until very recently. It has been com- 

 mon knowledge for centuries that young elvers 

 run up into fresh water in spring, and adults 

 journey downstream in autumn. A host of myths 

 grew up to explain the utter absence of ripe eels 

 of either sex, either in fresh water or along the 

 seacoast. But it was only a few years ago that 

 the breeding places of the European and American 

 eels were discovered and the history of their larvae 



« Jour, of Exper. Zool., vol. 88, 1945, No. 3, pp. 211-234. 



Figure 69. — Eel (Anguilla rostrata). A, adult, Connecticut River, Massachusetts; from Goode, drawing by H. L. 

 Todd; B, "Leptocephalus" stage, 49 mm.; C, "Leptocephalus" stage, 55 mm.; D, "Leptocephalus" stage, 58 mm.; 

 E, transformation stage, 61 mm. B-E, after Schmidt. 



