Thanks Ron for this find! Solitary tunicate, found on the underside of a rock in the low intertidal. About 1/2" across. Two siphons visible.
This appears to be Metandrocarpa dura, or Fused Orange Social Ascidians, growing on a rope hanging off the dock that I pulled up briefly. The rope had many Botryllus schlosseri or Harbor Star Ascidians growing on it, too.
Suddenly I noticed Diplosoma listerianum, or Gray Encrusting Compound Tunicates, growing bundantly on the wooden sides of the docks. At first I thought it was a gray sponge, then found a photo on p.356 in Lamb & Hanby that matched.
These Corella inflata, or Brooding Transparent Tunicates, were hanging from a rope I briefly pulled out of the water. It was hanging off the dock, covered in Botryllus schlosseri and these clear tunicates. The size varied from1/4" to 2".
Here are two photos of Botryllus schlosseri or Golden Star Tunicate, aka Harbor Star Ascidian, a beautiful bright yellow-orange ascidian. One photo shows it living underwater in the marina, and the other living on a rope I briefly pulled out of the water on the dock. I had photographed the same rope with the same ascidians two months ago, and they look much the same! I'm curious about its two names- here it's called a tunicate and in Lamb & Hanby an ascidian.
On dock at Princeton Harbor. About 1" high. AKA Mushroom Compound Tunicate as per Lamb & Hanby, p. 353.
it was specific name on plate but I missed it.
at Suma aquarium.
Ascidiacea (commonly known as the ascidians or sea squirts) is a class in the Tunicata subphylum of sac-like marine invertebrate filter feeders. Ascidians are characterized by a tough outer "tunic" made of the polysaccharide tunicin, as compared to other tunicates which are less rigid.