Mystery Organism – A Jellyfish With a Stalk?!

By The Marine Detective on September 4, 2010

Blog updated on June 28, 2022.

Yes, it is species of stalked jellyfish (stauromedusae). The species well documented on our coast is the “Oval-Anchored Stalked Jelly” (Haliclystus sanjuanensis). Read below for what is believed to be a new (undescribed) species!

Stalked jellies never become free-swimming, bell-shaped “medusa” like most jellyfish species. Their stalk is sticky allowing them to attach to Eelgrass, seaweed, or rocks in the shallows.  They have 8 “arms” that look like they have pom-poms at their ends.  These clusters of 30-100 tentacles have stinging cells so that the stalked jelly can catch small crustaceans with the pom-poms and bring this food to their mouth (positioned at the centre of the 8 arms).

They are remarkably mobile which you will see in the Lester B. Pearson College video at the end of this blog. If the stalk becomes detached, the animal can hold on with its tentacles till it reattaches its stalk. The student video will also allow you to see the base of the stalk and how the arms can close up.

Only about 50 species of stalked jelly had been discovered worldwide. New extremely deep-dwelling species been discovered around hydrothermal vents AND . . . potentially also in the shallows in front of my community on northeastern Vancouver Island. 

After the above photo went into the world in July 2019, it led to contact with researcher Claudia Mills. She let me know this is an undescribed species (also genus Haliclystus). This is such testament to how little we know about the Ocean. Again, this was in the shallows at only approximately 1 metre depth very near to where I live.

Claudia also thought that the stalked jelly that Gillian and Erin found is likely also the undescribed species. Please note that these are NOT the only known sightings of this “new” species. Their range is believed to include the San Juan Islands (Washington) to southeast Alaska and possibly even northern Japan and sightings go back decades. See Neil McDaniel’s photo form the 1970s below.

I had hoped to find the species again since July 2019. Finally, I had success on June 27, 2022. See photos below. These stalked jellies were again at only about 1 metre depth in the same location as the 2019 “find”.

Limitations in finding the species again were:
(1) That I think it is more likely to be found in the summer months when the visibility while diving is limited due to the richness of plankton in the water column; and
(2) Needing a dive buddy who is willing to gear up in thick neoprene in the summer and do a beach dive when it is usually hotter and much more difficult to see around you in the water. Diving from the beach usually involves more exertion than just rolling off a boat into the ocean. Also the visibility tends to be worse for beach dives because these locations often don’t get as much tidal flushing as do dive sites in narrow passes between islands.
Thank you buddies Natasha Dickinson and Jacqui Engel.

YOU could find this species of Oval-Anchored Stalked Jelly too and carefully document it (not touching it and also being really careful in its habitat e.g. avoid stepping on Eelgrass). Your chances are likely best in summer, on a low tide.

You could upload the sighting to iNaturalist where Claudia Mills would ID. On a recent sighting there she shared: “This is the “other” uncommon, species of Haliclystus that we have found in BC and Alaskan waters. It is usually found in (environmentally) undisturbed quiet bays, on kelp or eelgrass in the shallow subtidal.”

For this Oval-Anchored Stalked Jelly to be “described” and get a species name, experts like Claudia would write up and publish their research on how the species is physically and genetically different.

Note that this is an older video. I think we would be less inclined to touch the animal directly these days.