544 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



joint of the head tentacle is provided with re- 

 tractor muscles by which it can be withdrawn 

 rearward into a tunnel-like sheath along the head 

 and back, bringing the "bait" close to the mouth. 



Bertelsen 98 has found (from dissecting a West 

 Greenland specimen) that when this happens, the 

 rear part of the hard axis of the head tentacle, 

 which is enclosed in the very elastic skin, emerges 

 from the back of the fish, about midway between 

 the caudal fin and the base of the pectoral fins, 

 so as to form the axis of a slender, tapering "dorsal 

 tentacle." Thus this extraordinary and unique 

 structure, which has been the subject of much 

 discussion, is actually the rear end of the head 

 tentacle which protrudes when the latter is drawn 

 rearward. 



When the cephalic tentacle is moved forward by 

 its protractor muscles, its protruding rear end is 

 withdrawn into the tentacular sheath, either par- 

 tially, when the so-called dorsal "tentacle" appears 

 as a short fingerlike process, or wholly, leaving 

 simply an indentation or pore in the midline of 

 the back, as it is in the Gulf of Maine specimen 

 pictured in figure 288. 



Close behind the so-called "dorsal tentacle" (or 

 behind the pore representing the latter) are a pair 

 of low, fleshy appendages or "caruncles," scarcely 

 noticeable on large specimens, but more con- 

 spicuous on small. These have been interpreted 

 as vestiges of the first dorsal fin, for each of them 

 encloses a spine that can be felt if not seen. Their 

 function is not known." 



The skin is strewn with small prickles on very 

 small specimens, but is close-set with low conical, 

 broad-based thorns on larger fish. The eyes are 

 minute, seemingly functional on small fish, but 

 covered over by skin and apparently blind on 

 large ones. The gill slits are very small, C-shaped; 

 placed below the pectorals and a little behind 

 them. The small, slender, sharp-pointed teeth 

 are directed into the mouth. The dorsal and anal 

 fins each have 4 rays, thick, fleshy, and tapering, 

 as the caudal rays are also. The central caudal 

 rays are forked. The caudal fin has been de- 

 scribed as occupying as much as two-fifths of the 



total length of the fish when it is intact. 1 But it 

 has been much damaged in most of the specimens 

 that have been seen, and the membranes of all 

 the fins have been mostly torn away. 



Color. — Small ones are jet black, but the dermal 

 prickles, being colorless, show white against the 

 black skin on large specimens, giving a granulated 

 black and white appearance. 



Size. — The largest specimen seen so far 2 was 

 26% inches (68 cm.) long to the base of the tail fin, 

 and about 47 inches (119 cm.) long, counting the 

 tail fin. 3 



The parasitic males are fastened to the ventral 

 side of the female, by two outgrowths from the 

 front of the head, that are fused at the tip. They 

 have no teeth, no tentacle-like spine and no eyes, 

 and the alimentary canal is vestigial ; in fact, about 

 the only important internal organ is a large testis. 

 But their fins resemble those of their mates, as do 

 the gill openings; their skins are prickly; and they 

 are similarly black. Those that have been seen (1 

 or 2 per female) have ranged from about 3% inches 

 (85 mm.) long to about 6 inches (150 mm.) long 

 (Gulf of Maine specimen). 



General range. — Oceanic and apparently cosmo- 

 politan, for adults have been reported from Green- 

 land; Iceland (where it has been taken the most 

 often); off Nova Scotia; Gulf of Maine; near the 

 Azores; and in the sub-Antarctic. Young speci- 

 mens apparently referable to this species are re- 

 ported off southern New England; from the 

 Caribbean; near the Canaries; north of the Cape 

 Verde Islands; from the South Atlantic (lat. 

 52°25' S., long. 9°50' E.); and also widespread in 

 Indo-Pacific waters.* 



Occurrence in the Gulf oj Maine. — A female, 

 about 32 inches long to the base of the caudal fin, 

 and about 40 inches counting what remained of 

 the latter (fig. 288), with one male attached, and 

 showing the scar of attachment of another, was 

 taken 12 miles south of Mount Desert rock, at 125 



•• Vid. Meddel. Dansk Naturh. Foren., vol. 107, 1943, pp. 190-193; see 

 especially his fig. 4, p. 192. 



» See Regan and Trewavas (Rept. 2, Danish Dana Exped. (1928-1930), 

 1932, pp. 23-24) for an account of the lateral line papillae in different families 

 of deep sea anglers. 



1 This was the case in the specimen about 47 inches (1 19 cm.) long described 

 by Kroyer (Naturhist, Tiddsskr., Ser. 2, vol. 1, 1844, pp. 640-642); also in 

 one pictured by Qoode and Bean (Smithsonian Contrib. Knowl., vol. 31, 

 1895, pi. 117, fig. 399, after Gaimard). 



* Krdyer's original specimen from Greenland. 



' See Clarke (.Discovery Rept., Vol. 26, 1950, p. 14, table 1), for measurements 

 of several specimens. 



< For complete list of localities for adults and young, see Clarke, Discovert/ 

 Rept., vol. 26, 1950, pp. 23. 30. 



