156 



FISHERY BULLETIN OP THE FISH AND "WILDLIFE SERVICE 



have repeatedly been known to become fully ripe, 

 females nearly so, 67 then invariably dying. The 

 ripening of the sexual products is accompanied 

 by changes in the shape of the head ; in the loss of 

 the teeth; and in a jellification of the bones, while 

 the eyes of the males become enormous and the 

 females become much distended by the ovaries. 

 It is probable that the American conger ripens 

 off the coast of southern New England in summer; 

 European congers in captivity have been known 

 to do so every month in the year except October 

 and November. 



It seems that the conger, like the common eel, 

 moves out from the coast to spawn, for its young 

 larvae have never been taken inshore, and Dr. 

 Johannes Schmidt's 68 discovery of very young 

 larvae in the West Indian region, but nowhere 

 else, points to this as the chief spawning ground 

 of the American conger, if not the only one. 



The congers are extremely prolific fish, the 

 number of eggs a European female may produce 

 having been estimated as high as 3 to 6 millions. 

 American conger eggs have never been identified, 

 for although eggs taken over the tilefish grounds 

 30 miles south of Nantucket lightship in July 

 1900 69 have been credited to this species, there is 

 no certainty that this was their true parentage. 



It has long been known that the congers, like 

 the common eels, pass through a peculiar ribbon- 

 like larval stage (the so-called "leptocephalus") 

 very broad and thin and perfectly transparent, 

 with a very small head. 70 In fact the first lepto- 

 cephalus ever seen (about 1763) was the larval 

 European conger. But its identity was not estab- 

 lished definitely until 1886, when the famous 

 French zoologist, Delage, 71 reared one through 

 its metamorphosis at the biological station at 

 Roscoff. 



The leptocephalus stage of the conger is rela- 

 tively more slender than that of the common 

 eel, it grows larger (to a length of 150-160 mm.), 

 and its vertebrae and muscle segments are far 

 more numerous (140-149 in the American conger, 



* Cunningham (Jour. Mar. Biol. Assoc. United Kingdom, N. Ser., vol. 2, 

 1891-92, pp. 16-12) gives an Interesting account of this and other phases of the 

 life history of the conger. 



» See Nature, vol. 128, 1931, p. 602, for a discussion of this question by Dr. 

 Schmidt. 



« Eigenmann, Bull. U. S. Bur. Fish., vol. 21, 1902, p. 37. 



'• For photographs of the leptocephalus stage of the European conger, see 

 Schmidt, Rapp. et Proc. Verb. Cons. Perm. Intemat. Eiplor. Mer, vol. 5, 

 No. 4, 1906, pi. 9, flgs. 8, 9; and Meddelelser Komm. Havundersiigelser, Ser. 

 Flskerl, vol. 3, No. 6, pi. 1, flgs. 1-3. 



" Conptes Rendus Acad. Scl. Paris, vol. 103, 1886, p. 698. 



154-163 in the European) than in the common 

 eels (about 107 in the American eel and about 

 114 in the European). But the number of body 

 segments (visible only under a lens) is not of itself 

 a safe clue to identity, for there are as many or 

 more in the long-nosed eel (p. 158) which has been 

 reported in the Gulf; also in the mo rays, and in 

 various other members of the eel tribe. 72 



The duration of the larval period of the conger 

 is not known. The process of metamorphosis 

 consists essentially in a thickening and narrowing 

 of the body, an enlargement of the head, the for- 

 mation of the swim bladder and permanent teeth, 

 and the development of pigment in the skin, a 

 change that occupied about two months (May to 

 July) in the case of Delage's European specimen. 

 His young conger was 9.3 centimeters (3.6 inches) 

 long at its completion. 73 



General range. — Continental shelf of eastern 

 America: adults are known north to the tip of 

 Cape Cod; larval stages to eastern Maine. Its 

 southern boundary cannot be stated until the 

 congers of the coasts of North and of South 

 America have been critically compared. It is rep- 

 resented by a closely allied species (Conger conger) 

 in the eastern North Atlantic. 



Occurrence in the Gulf of Maine. — The only 

 records for adult congers within the limits set here 

 for the Gulf of Maine are of one taken at North 

 Truro, Cape Cod; a second specimen trawled 

 close to Provincetown in Cape Cod Bay, July 5, 

 1951, by Capt. Herman Tasha; and a third, 

 trawled south of Nantucket shoals by Albatross 

 III, in mid May 1950. 7 * But the conger must be 

 much more plentiful at times off the shoals than 

 the foregoing would suggest for Capt. Henry 

 Klim of the dragger Eugene H reports trawling 

 1 ,400 pounds of them there, at 76 fathoms, March 

 25-30, 1951." And its curious band-like "lepto- 

 cephalus" larvae have been found within the Gulf 

 on several occasions. Thus, half a dozen speci- 

 mens were picked up on the beach at Cherryfield 

 and Old Orchard, Maine, and at Nahant, Mass., 



» Fish (Zoologlca, New York Zool. Soc, vol. 8, 1927, pp. 307-308) gives a 

 table of the numbers of body segmentsfor various eels and for "leptocephalus" 

 larvae of known and unknown parentage. 



» Schmidtleln (Mittlell, Zool. Stat. Neapel, vol. I, 1879, p. 135) speaks of 

 young "congers" at Naples In April as hardly one-third as long as this, a 

 discrepancy suggesting that these may actually have belonged to one of the 

 Muraenold eels. 



» Local reports of congers do not necessarily relate to the true conger, for the 

 eel pout (p. 510), which Is common In the Gulf, Is often misnamed thus. 



" At lat. 40° N., long. 69° 50' W. 



