FISHES OF THE GULF OF MAINE 243 



Color. — We have never seen this fish alive, but it is described as very beautiful, 

 dark steel blue above shading into green with silver, purple, gold, and lilac luster on 

 the sides and rosy on the belly, with vermilion fins, while the whole body is speckled 

 with silvery and milk-white spots. 



Size. — The opah grows to a length of 3 to 6 feet; usually 3 to 4 feet. 



General range. — Open waters of the Atlantic and Pacific Oceans. Recorded off 

 the Madeiras, Scandinavia, the British Isles, Norway, Iceland, Newfoundland, 

 Nova Scotia, Maine, and Cuba. 



Occurrence in the Gulf of Maine. — We include the opah here because it is said 

 to have been taken off Maine." We find no more definite record of it within the Gulf 

 of Maine, but one was caught off Sable Island in 1856 and a second oft' La Have 

 Bank many years ago. 



Habits. — The opah is usually spoken of as a deep-sea fish, but this is a misno- 

 mer, for off Madeira, where it is taken in some numbers, it is caught on hook and 

 line at 50 to 100 fathoms depth only. Being so rare off our coast we need merely 

 note that it feeds chiefly on squid, isopods, and small fish, as well as on seaweeds; 

 that it is an excellent food fish; and that nothing is known of its breeding habits. 



THE RUDDERFISHES. FAMILY CENTROLOPHID.a;. 



94. Barrelflsh {Palinurichthys perciformis MitchiU) 



Logfish; Rudderfish; Black pilot 



Jordan and Evermann, 1896-1900, p. 964. 



Description. — The reduction of the spinous portion of the dorsal fin of the 

 barrelfish to 6 to 8 short detached spines, each with a small triangular fin membrane, 

 closely followed by a large soft-rayed dorsal fin, marks it off from all other Gulf of 

 Maine fishes except certain of the pompano tribe. There is no danger of confusing 

 it with any of the latter, its caudal fin being only slightly emarginate instead of 

 deeply forked and its caudal peduncle moderately stout and without keels instead 

 of very slender. Wlaile it suggests a cunner in general appearance, especially in its 

 rather stout body (about two-fifths as deep as long, not counting the caudal), 

 bluntly rounded nose, convex profile, and smaU mouth, its rudimentary spiny 

 dorsal is a ready field mark to distinguish it from the latter. The soft dorsal fin 

 (20 to 22 rays) rises about midway from tip of snout to base of caudal; the ana 

 (16 or 17 rays) is somewhat farther back. Both these fins are moderately high and 

 taper slightly from front to rear. The anal is preceded by three short spines so nearly 

 imbedded in the skin as to be hardly visible. Both the ventrals and the pectorals are 

 large with rounded tips. The top of the head is scaleless but the body is clothed 

 with small rounded scales. 



Color. — Described as varjang from blackish to green, and either as dark below 

 as above or paling to bluish white on the belly, variously mottled with darker dots 

 and bars. It is said to change color to accord with its surroundings. 



' Goode and Bean, 1896, p. 223. 



