FISHES OF THE GULF OF MAINE 11 



KEY TO GULF OF MAINE FISHES 



Key A 



1. Mouth soft with no bony jaws; form eel-like; no pectoral fins 2 



Mouth has bony jaws; pectoral fins present if form is eel-like 3 



2. Two separate fins on back; no barbels on snout Lamprey, p. 18 



Only one fin on back; barbels on snout Hag, p. 16 



3. Bones of head fused in a tubular snout, with mouth at tip Key B, p. 12 



No tubular snout 



4. One or both jaws greatly prolonged as a bony sword or bill Key C, p. 12 



Neither jaw greatly prolonged 5 



5. Five or more pairs of large gill openings (on sides of neck in sharks; on lower surface 



in skates) " 



Only one external gill opening, large or small, on each side 7 



6. General form cylindrical Sharks, key, p. 23 



General form flat and disklike, with long whiplike tail Skates and rays, key, p. 57 



7. Body abruptly square-cut close behind the very high dorsal and anal fins. Sunfish, p. 301 

 Body with distinct tail 8 



8. Large sucking plate or disk, either on the top of the head or on the chest 9 



No sucking disk or plate H 



9. Sucking plate on top of head Remora family key, p. 349 



Sucking disk on chest 10 



10. General form like a tadpole; anal fin originates about as far back as the tip of the 



pectoral Sea snail family key, p. 340 



General form not like a tadpole, but high arched with longitudinal ridges; anal fin 

 originates far behind tip of pectoral , Lumpfish family key, p. 334 



11. Tail like a shark, i. e., with upper lobe much longer than lower Sturgeon, p. 75 



Tail nearly symmetrical 12 



12. Whole head and body clothed in continuous armor of bony plates.. Alligator fish, p. 333 

 If bony plates are present they do not form a continuous armor over head and body — 13 



13. No clear separation between anal and caudal fins, which together form one contin- 



uous fin (anal portion may be either long or short) Key D, p. 12 



Anal and caudal fins separated by a deep notch if not by a space 14 



14. There is a fleshy (adipose) fin with neither spines nor rays behind the rayed dorsal 



fin Key E, p. 13 



A fleshy flap 5 in front of dorsal fin Tilefish, p. 352 



All dorsal fins supported by rays or spines, which can be felt if not seen; without fleshy 



lobes or adipose fins either in front of or behind them 15 



15. Head fringed with fleshy tags or flaps; much broader than body 16 



Head not fringed with fleshy flaps 18 



16. Lower jaw projects far beyond upper, exposing very large conical teeth even when 



mouth is closed; two long isolated spines on top of head in front of eyes. Goosefish, p. 524 

 Lower jaw does not project noticeably beyond upper; teeth small; no long isolated 

 spines in front of eyes 17 



17. First (spiny) dorsal fin longer than second (soft rayed); neither is fleshy. Sea raven, p. 330 

 First (spiny) dorsal fin much shorter than second (soft rayed); both thick and 



fleshy Toadfish, p. 357 



' Although this flap suggests the adipose fin of a salmon in appearance, it is not actually an analogous structure, but simply 

 a lobe of skin. 



