A slim translucent fish shaped like a ribbon, tapering to a point, with no scales, no pelvic fins and effectively no tail. Everything about the body is built for fitting into a space that was not meant for it.
It lives inside a sea cucumber. The fish finds a host by smell, waits at the rear opening, and enters tail-first through the anus in a single quick reverse, sometimes taking several attempts. Once inside it occupies the body cavity or the respiratory trees, and by day that is where it stays - which is why the usual sighting is a fish head sticking out of a cucumber.
At night it comes out to hunt small crustaceans over the sand and returns before dawn, often to a different individual. Some relatives in the family are true parasites and eat the host's gonads; this one appears to take shelter only, though the distinction is thin when your bedroom is somebody's respiratory system.
The host is not defenseless. Sea cucumbers can eject sticky tubules or contract violently to expel a lodger, and pearlfish are occasionally found dead inside cucumbers that won the argument.
The genus. Encheliophis Müller 1842 - énchelys (eel) + óphis (serpent). ETYFish
The species. Encheliophis homei (Richardson 1846) - Honours English surgeon-naturalist Everard Home. ETYFish
- slim translucent eel-shaped fish with no scales and no pelvic fins
- tapers to a point with no tail fin worth the name
- seen as a head protruding from the rear end of a sea cucumber
- length up to 19 cm
Why it's threatened
There are no known major threats.
Threat classification from the IUCN Red List.
