Carapidae
by L. B. Trott and J. E. Olney
Eel-like fishes, compressed or cylindrical body tapering to a slender tail; anus located behind, below or immediately anterior to pectoral fin base. Supra-maxilla absent; mouth with fine teeth on jaws and palate, sometimes with large fang-like teeth; predorsal bone sometimes present. Anal finrays longer than opposing dorsal finrays; pectoral finrays usually present (absent in Encheliophis); pelvic fins usually absent (present in Pyramodon); specialized pelagic larva characterized by the possession of an elongate predorsal filament or vexillum.
Species of Echiodon (as well as Pyramodon and Snyderidia) are free-living fishes inhabiting both shallow and deep-water habitats (Maul, 1976). Adults of Carapus (and remaining genera) are inquiline in the body cavities of echinoderms (sea-cucumbers, starfishes) and bivalve molluscan hosts. Some species display host parasitism and cannibalism. Although little is known of most pearlfish life cycles, the biology of a few species has been treated (Emery, 1880; Arnold, 1956; Smith and Tyler, 1969; Trott 1970, 1981; Smith et al., 1981). Carapid larvae (also known as vexillifers) are distinctive and have been described for a number of genera (Olney and Markle, 1979; Markle and Olney, 1980; Govoni et al., 1983). The pelagic larva transforms into a specialized prejuvenile stage, known as a tenuis larva, which settles to the bottom and finds a host in symbiotic species.
Genera 7; in Clofnam area 2.
Recent revisions: Arnold ( 1956 subfamily Carapinae), Cohen and Fig Nielsen (1978- review of the genera).