Never come across a cutthroat eel? That’s not surprising. Although there are around 41 species of cutthroat eel distributed throughout the world, these eels live in deep waters near the sea floor.
Credit: NOAA Office of Ocean Exploration and Research, Windows to the Deep 2019 (CC BY-SA 2.0)
Like many other deep-sea species, we don’t know a great deal about their lives... but we do know some things. Here are three things we’ve learned about these slender deep-water dwellers.
1: They’ll happily swarm around food
In 2018, researchers popped a baited video camera (i.e. a camera with food nearby) near a seamount in the Clarion Clipperton Zone (Pacific Ocean). It attracted the attention of some 100 eels (species Ilyophis arx). Apparently, this is “the highest number of fishes ever recorded per kg of bait/carrion below 1000 meters” and “the highest number of fishes that has ever been recorded at carrion of any kind or size at abyssal depths.”
2: They can be very long
In 2017, researchers near the Paganini Seamount (Pacific Ocean) filmed a shortdorsal cutthroat eel coming in at 127 centimetres in length! Apparently, before this particular eel was spotted, the longest shortdorsal recorded was 111 centimetres in length.
3: They’re not super-fast swimmers, but not super-slow either
There haven’t been many studies that looked at cutthroat eel swimming speeds, but one looking at northern cutthroat eels (Synaphobranchus kaupi) found they swim at a mean undulation bout of 1.5 beats per second, resulting in a travel distance of around 0.6 - 0.9 body lengths per second.
Wondering what an undulation bout is?
If you look back at the video above, you see they move their whole body a bit like waves. Each one of those is an undulation bout.