Family Liparidae

Common names:  snailfishes

Distribution:  Worldwide from the intertidal to 7500 meters.  A few species are pelagic but the majority are benthic.

General description and features:  These fishes have the general appearance of a tadpole with a large head and body which tapers to a very small tail.   They have long dorsal and anal fins which often merge into the tail to give the appearance of a single continuous fin.  Their pectoral fins are very close to the operculum and they have a sucking disk under the throat which is derived from some of their pelvic fins.  In some species the disk has been secondarily lost or reduced to a few bony elements.  This is often the case in deep-sea species arguably because it was originally evolved in shallow water forms for attachment to rocks in wave exposed intertidal and subtidal environments.

Feeding:  Primarily polychaete worms and small crustaceans but diet varies with species and habitat.  Some specialists are known such as Paraliparis rosaceus which feeds on holothurians (sea cucumbers)

Reproduction and life history:  Many snailfishes have large eggs (2.5 to 8mm) and very low fecundities (~15-1600 eggs) which would suggest some form of parental care.  However this has never been demonstrated in deep-sea species.  Several species in the genus Careproctus are known to lay their eggs in the branchial cavity of deep living king crabs (Lithodidae).

The above two images are Careproctus longifilis filmed in Monterey Canyon just off the bottom at 3000 meters.  In the top image you can see the sucking disk in between the pelvic rays.  This species has very developed pores on the head.  These are part of the latero-acoustic system which includes the lateral line and functions to sense water movements and the vibrations of the movements of other animals, both potential predators and prey.  In the deep sea, where vision is often a less important sense, the lateral line and head pores are often very well developed as in this species.