washed up velella

pacifica beach CA there were tons of velella (sail jellyfish) washed up on shore, did quick research and apparently it can be caused by warmer waters after winter season not 100% sure although the water temp was warmer than normal this time of year and was my first time seeing these guys. sea piggies or sand fleas were also washed up with the jellies at the shoreline not sure what caused them to wash up though. the dead velella were white-ish and would actually flake up resembling the shedded skin of a reptile while the alive beached ones were a deep purple blueish color and jelly textured body on the bottom with a clear sail like limb on top. the bottom portion of the jellyfish have a pattern on them similar to that of a seashell (ridge pattern) while being of a rounded medium sized creature.