A Moment of Holothurian Behavior

Just recently I had the incredible pleasure of witnessing a bit of holothurian behavior. It was something I never would have thought I’d see. I’ll tell you more down below!

Enypniastes, a free swimming holothurian in the Gulf of Mexico.

In highschool I studied marine biology and was particularly interested in the phylum Echinodermata. I chose to write a paper on sea stars at the time and have written other material on them since. More recently I have been drawn to their relative, holothurians, due to my exposure to them by both NOAA’s Okeanos Explorer expedition of the North Atlantic in 2013 and the Nautilus in the Gulf during the same year.


Last year I wrote an article entitled Holothurian Distinction. In it I touched on some of the differences in the phylum Holothuroidea but I placed specific emphasis on the genus Enypniastes. From the brief footage taken by the Nautilus I could see that there were at least a few kinds of purple holothurian popular to the Gulf but no one mentioned the species names. Some were fairly translucent species rimmed with “frills”, remaining upon the seafloor as most holothurians do and others were more spiny. But there was one that stood out and I found out later it was called Enypniastes. The genus Enypniastes has a fin surrounding the oral and aboral sides which it utilizes in its swimming habits, as it is known as a free-swimming holothurian. It is unique in its abilities to swim because as I said earlier, holothurians are benthic creatures, meaning they dwell on the sea floor. The Enypniastes flutters its webbed fins while contorting its body to propel itself into the water column only to lazily settle back onto the sediment just a few feet away.

Enypniastes feeding.

During a past dive, the Okeanos and every one watching had the remarkable opportunity to see an Enypniastes feeding. With finger like tentacles, the holothurian moved along the sea floor reaching out, grabbing “fistfuls” of sediment and shoving them into its mouth. It didn’t discriminate but ate whatever it picked up. The sediment was then processed through its long coiled gut leaving a trail of fecal matter behind. The rate at which it does this is surprising but I guess when a creature ingests sediment at that rate with the intent to sort through its finds it’s bound to happen just so.

Enypniastes feeding.

I can’t tell you how exciting this is for me to be able to see first hand. After the difficulties of researching and not finding satisfying results, I have nearly all my questions answered in just a few minutes of live footage. It was truly an delightful experience, one of many I’ve had so far since discovering NOAA’s telepresence treat. I thank NOAA’s Ocean Explorer profusely for this amazing learning ability.

If you’d like to get in on these experiences, watch them live at Ocean Explorer.

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