Animalia Life

Cryptopsaras couesii
FAMILY
Ceratiidae
TAXONOMY
Cryptosaras couesii Gill, 1883.
OTHER COMMON NAMES
None known.
PHYSICAL CHARACTERISTICS
Like other midwater anglerfishes, the seadevil is characterized by the absence of pelvic fins, pseudobranchs, and scales or other dermal derivatives. Moderate to extreme degrees of sexual dimorphism characterize members of this suborder. Ceratiids exhibit extreme sexual dimorphism, with the adult males being reduced to ectoparasites of the females. As with most species, the lure (esca) appears to be bioluminescent in the seadevil. Female seadevils have a vertical to strongly oblique mouth, and the first two or three rays of the soft dorsal fin are modified as caruncles (low, fleshy appendages).
DISTRIBUTION
Their
DISTRIBUTION
is worldwide between 63° N and 43° S latitudes.
HABITAT
The species inhabits the lower mesopelagic and bathypelagic zones, between 246 and 13,123 ft (75–4,000 m), but is most commonly found between 1,640 and 4,101 ft (500–1,250 m).
BEHAVIOR
Little is known besides feeding ecology and
REPRODUCTIVE BIOLOGY
.
FEEDING ECOLOGY AND DIET
Ceratioid anglerfishes, like the seadevil, are one of the most important groups of predatory fishes in the lower mesopelagic and bathypelagic zones of the world oceans. Feeding is by aggressive mimicry using the angling apparatus. They feed upon zooplankton and nekton, with fishes and cephalopods probably forming a major component of the diet.
REPRODUCTIVE BIOLOGY
The reproductive adaptations found among the ceratioid anglerfishes are among the most fascinating in the animal kingdom. As mentioned earlier, all lophiiform anglerfishes appear to have some degree of sexual dimorphism in the structure and size of the olfactory organs. It is assumed that this is associated with the females’ production of species-specific pheromones, which attract the males when the female is ready to breed. In ceratioid anglerfishes this sexual dimorphism has reached its extreme, not only among the vertebrates but also perhaps the entire animal kingdom. In most of the 11 ceratioid families, the female is considerably larger than the male (females range from three to 13 times the length of conspecific males). Furthermore, in at least four ceratioid families the males have been so drastically reduced that they have become essentially a pair of swimming testes directed by a huge pair of olfactory organs. Once these “minimized” males find a female, they attach themselves to her with their jaws, eventually achieving histological fusion and leading the remainder of their lives as essentially a pair of “ectoparasitic” testes.
CONSERVATION STATUS
Not threatened.
SIGNIFICANCE TO HUMANS
None known.

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