GENERAL REMARKS FOR SUBORDER CERATIOIDEI BY E. BERTELSEN
A suborder of Pediculati (Lophiiformes) distinct from other members of the order in lacking pelvic fins (except in larval Caulophrynidae), first cephalic finray (illicium) of females with distal bulb-shaped light-organ (esca) (except in Caulophryne, Rhynchactis and Neoceratias), second cephalic finray rudimentary and subdermal (except in certain Diceratiidae and juvenile Ceratiidae), having extreme sexual dimorphism with dwarfed males (parasitic in some families), lacking external illicium and with teeth of jaws replaced by hooked denticles on tip of snout and lower jaw. (Denticles in most species fused at base forming ossifications termed upper and lower denticular.) Eleven families, 33 genera and about 120 species of which 9 families, 18 genera and 36 species are recorded from the Clofnam area. As listed below, additionally 10 genera, including representatives of the two remaining families, are known from other parts of the Atlantic north of the equator and might appear in the area. As the total number of recorded specimens of many of the recognized species is still very small (less than 10 metamorphosed females of each of 18 of the 36 species observed in the Clofnam area) distribution as well as intraspecific variation of their diagnostic characters are insufficiently known. For this reason the probability is relatively high for obtaining specimens which do not fit into the following keys and descriptions, representing either species not previously known from the area, extreme intraspecific vanatlon or even new specles. Meso- and bathypelagic mainly in tropical and subtropical parts of the oceans, absent in the Mediterranean. Females solitary, passively attracting prey by means of illicial apparatus; males actively seeking mates by means of highly developed sense organs, attaching themselves to the females by means of the jaw denticles and in some families becoming parasitic on them through a fusion of tissue and blood-vessels. Females feeding on fishes, cephalopods, crustaceans. Eggs released in gelatinous veils; larvae epipelagic. Found in all oceans between approximately 65° N and 65° S. In Clofnam area absent in the Mediterranean, larvae and unattached males absent north of about 40° N, young females reaching Irish continental slope and adult probably expatriate females, some with parasitic males, occurring off the south and west coast of Iceland.
Recent revisions: Bertelsen (1951), Pietsch (1972).