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Hello, I work on sponges for my PhD and I am pretty certain that is a tunicate.
Sponges can be difficult to tell apart from other benthic organisms, particularly some ascidians (sea squirts or tunicates). All sponges have ostia (pores), which is where the water enters the sponge, and at least one oscule (larger holes) for the water to exit the sponge. Ascidians either have two siphons to allow water in and out or they have very regularly arranged small oral siphons; sponges generally dont tend to have very regularly arranged oscules. The easiest way to tell them apart is to gently waft your hand near the animal, if the animal contacts its openings quickly it is likely to be an ascidian. Sponges can contract, but they do it much more slowly. Finally, if you look very closely at the smaller openings of an ascidian they are likely to be star shaped and they also look more regularly spaced than most sponges.
Hope this helps!
Hello there,
I've not worked in the Pacific Northwest I'm afraid! I can tell you that from the photo definitely two different organisms. I would say the yellow one is a demosponge but it is hard to tell exactly which one without a close up as I can't see the surface detail and ideally a sample so I can see the skeleton (spicules). The red one I think is a compound ascidian, but it could be a sponge again I would have to look a bit closer! Did they both have the same pattern of of pore distribution on their surfaces?