Family Zoarcidae

Common names:  eelpouts

Distribution:  Worldwide from the intertidal (at the poles) to 5000 meters.  A few species are pelagic but the majority are benthic.  Pelagic genera include Melanostigma and Lycodapus.

General description and features:  The basic body form is eellike.  Most species have well developed lips, large eyes, and what can only be described as a dopey look. The dorsal and anal fins merge with the caudal and the pelvic fins are reduced to about 2-3 rays or can be entirely absent.

Feeding:  Highly variable amongst members of the family from large fish predators to small species feeding on worms and tiny crustaceans.

Reproduction and life history:  Very little is known.  Several species of the shallow living Zoarces are live bearers.  For other species eggs are variable in size but often large and few in number.  They are are likely laid on the bottom.  Parental care may exist.  Melanostigma atlanticum was found in a burrow with freshly laid eggs in the North Atlantic.  It could not be determined whether the fish was present in the burrow simply for egg laying or whether parental care would have ensued.  It does show that this midwater eelpout must return to the bottom for spawning suggesting that pelagic eelpouts have not entirely evolved mechanisms to separate their lives from the benthos.  

These pictures show a Pachycara sp. which was capture in a baited trap on the bottom at 3500 meters off Monterey Bay. This is a fairly large species for the family at about 18 inches (Photos by J. C. Drazen).  

This is a midwater eelpout, Melanostigma pammelas, that commonly is seen during ROV dives in Monterey Canyon.  It has the curious habit of curling into a ball when approached by the ROV or startle by other animals such as hake swimming about the lights of the vehicle (Robison, 1999).  It is thought that this behavior is a form of camouflage.  In the dimly lit waters of the mesopelagic predators primarily see shapes.  Long and thin shapes are characteristic of fish but round shapes are typical of jellyfish which have stinging tentacles and little nutritional value.  So by curling into a ball the eelpout can mimic the basic shape of the jellyfish which are rarely preyed upon.  For video footage of this behaviour take a look at the midwater research page and follow the link to shape change behaviour.  http://www.mbari.org/rd/midwater

Lycodapus mandibularis, another midwater eelpout that also exhibits the curling behaviour.  Both of the midwater eelpouts are kept alive in cold rooms in the laboratory at MBARI for a variety of physiological and energetics work (see current research to learn more).

Lycodes diapterus? a benthic eelpout filmed at 400 meters in the Monterey Bay.