Mottled Sea Squirt
The Mottled Sea Squirt is a colonial ascidian, with many identical individuals (clones) living within a common skin (test) in a crowded community of clones. Each of the tiny dots seen here covering the surface are actually the openings of each individual (the zooid). Each zooid inhales seawater, filters the food and other chemicals from the water, then exhales the filtered water through common openings, which are the large openings on the raised areas of the surface. Sea squirts also often have minute plant and bacterial cells living on the surface or inside the body cavity, which are able to convert sunlight to energy through photosynthesis, and thus supplement the diet of the sea squirt and give it a competitive advantage over its neighbours through more rapid growth. This encrusting species forms large continuous soft sheets that can smother corals and other sessile life forms.
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