Macrouridae
by P. Geistdoerfer
Body becoming compressed and strongly tapering behind short trunk to form a long 'tail' ending in a point, with at most a minute caudal fin. Head moderate or bulky; mouth terminal to inferior, jaws often protrusible, teeth on jaws, but absent from roof of mouth, their arrangement variable; chin barbel present in most species. Gill membranes free or narrowly united to isthmus, usually more or less connected; gills 4; branchiostegal rays 6-8. Pyloric caeca present. Two dorsal fins (except in Macrouroidinae, not found in Clofnam area), the first shortbased and high, with two spinous anterior rays (first often minute, second sometimes serrated along leading edge), the second dorsal fin continues to end of body, as also does the long anal fin; pectoral fins short-based, relatively high on body; pelvic fins small, thoracic or jugular, with 5-17 finrays. Light organ sometimes present along midline of abdomen. Scales cycloid, usually with spinules (but not on posterior edge), their form usually varying on different parts of body. Swimbladder usually well developed.
Large family of deepwater fishes, almost all benthopelagic on continental slope and abyssal plain of all oceans. Some species of commercial importance.
Subfamilies 4; in Clofnam area 3.
Genera 27; in Clofnam area 17.
Recent revisions: Marshall (1973), Marshall and Iwamoto (1973—western North Atlantic).
Bathygadinae
[subfamily]
Body elongate, compressed in caudal region. Snout blunt, mouth terminal and large; jaw teeth small or minute; chin barbel present or absent. First gill-slit not restricted by a membrane attached to the arch, gillrakers of first arch slender and numerous, others tubular or ridgelike; 7 branchiostegal rays. Anus just before origin of anal fin. Origin of second dorsal fin close behind end of first, the finrays longer than those of anal fin; pelvic fins with 7-10 finrays. Scales without spinules. No light organ.
Genera 2, both in Clofnam area. Recent revision: Marshall (1973—western North Atlantic).
Macrourinae
[subfamily]
Body elongate, compressed in caudal region. Snout rounded, blunt or pointed, sometimes long; mouth subterminal to inferior, more or less reduced in size, jaws protractile; chin barbel present or absent. Gill opening more or less restricted, first gill-slit restricted above and below by a membrane attached to the first arch, gillrakers on outer part of first arch usually tuberculate with denticles; 6-8 branchiostegal rays. Anus close to anal fin origin or some distance from it. First dorsal fin with 2 spiny finrays, the first reduced, the second with a smooth or a serrated leading edge; second dorsal fin not beginning close to first, its finrays shorter than those of anal fin. Scales usually with spinules. Light organ often present on belly.
Genera about 21; in Clofnam area 15.
Recent revisions: Marshall (1973—western North Atlantic), Marshall and Iwamoto (1973-genera Hymenocephalus,Coelorhynchus,Coryphaenoides and Nezumia).
Trachyrhynchinae
(subfamily]
Body elongate, compressed in caudal region. Snout pointed, very long, mouth inferior; jaws protractile, horseshoe-shaped, bearing a band of minute teeth; chin barbel small. First gill-slit not restricted by a membrane attached to the arch, gillrakers slender; 7 branchiostegal rays. Anus just before origin of anal fin. Second ray of first dorsal fin segmented, origin of second dorsal fin close behind end of first, the finrays somewhat longer than those of anal fin. Scales stout and spiny, with a ridge of modified scales on either side of dorsal and anal fins, each with a large compressed retrorse spine. No light organ.
Genera 1.
Recent revision: Marshall (1973—western North Atlantic).