Stalked jellyfish

The work of a curious fellow
For quite a while we thought this little stalked animal was some sort of anemone. It turns out that it is a jellyfish that lives its life as a solitary polyp rather than participate in the free swimming phase of jellyfish existence. It is a cousin of sorts to anemone as are all jellyfish. It does exhibit some quite anemone like behavior.
The Jellyfish, Haliclystus
Jellyfish rides dulse leaf
This stalked jellyfish can pucker up its stalk, shortening its length considerably, like the anemone. This shortening behavior seems to follow an event in which the jellyfish is stretched.
Haliclystus Retracted
Jellyfish Retracted
This stalked jellyfish attaches itself to algae, dulse in this case, presumably so that the tentacles are exposed to a greater volume of water by the waving action of the leaf. When the tentacles come in contact with anything that interests the jellyfish, the tentacles grab on to try to kill or capture the object. A stretching event, mentioned above, takes place when the wave action on the dulse tries to separate the jellyfish from its intended prey.
Haliclystus Grabs ROV
Jellyfish Grabs ROV
Here is a stalked jellyfish attached to a mussel. It seems smaller than the one on the dulse above. See if you can catch the very small lobster reaching a claw out through a gap in the rocks near the end of the clip.
Stalked jellyfish on mussel
Stalked jellyfish on mussel
This appears to be a particularly robust stalked jellyfish. It has an odd look about it, lacking the nice symmetry of the previous examples. The stalk seems twisted and the branches are irregular.
An odd stalked jellyfish
An odd stalked jellyfish