Chimaeridae
by M. Stehmann and D. L. Burkel
Body greatly tapering to a point, often ending with a filament. Males with a thumb-shaped retractable appendage on midfront of head, and a pair of similar retractable appendages in front of pelvic fins; eyes large; nostrils large, immediately in front of mouth, and connected to mouth corners by a roofed canal; a single gill opening, covered by an operculum-like flap, on each side; a system of easily seen mucous canals and sensory pores on head. Mouth underneath; two pairs of large cutting tooth-plates above and one pair below. Two dorsal fins, the first triangular with a stiff, movable spine as high as the fin, the second separated from it and much longer and lower; anal fin long and low, distinct from caudal fin in some species, the latter ending in a point, with or without a filament. Males with bifid or trifid claspers. Skin smooth and slippery, except for denticles on male organs.
Pelagic to benthopelagic, from near the surface down to deep-sea plains, but mainly found in deepwater; wide vertical range, rare (but locally common in upper slope areas); sluggish swimmers, the large pectoral fins serving as rudders, the hind part of the body undulating for propulsion; of fishery importance in a few areas. Feeding on small fishes and invertebrates. Oviparous; egg-capsules conspicuously large, mostly spindle-shaped, the embryos developing in about 9-12 months.
Genera 2, both in area.
Recent revisions: Bigelow and Schroeder (1953).