When most of us consider a slug or a snail, thoughts of gross, slimy creatures come to mind. However, the ocean paints these creatures in a much different light. Nudibranchs, often referred to as sea slugs, are some of the most brightly colored and beautiful animals in the ocean. These tiny, ornate sea creatures have adapted to life in the ocean in the most extraordinary ways, and although they are rarely noticed, they can be found right in our backyard. Here are a few we've spotted around Sanibel recently.
The Sargassum sea slug, Scyllaea pelagica, is commonly found floating in clusters Sargassum algae. With leaflike projections on its body, this nudibranch is able to blend seamlessly with its environment. These little guys ingest the air-filled spherical floats on the algae, which allows them to stay afloat while searching for their favorite food, tiny hydroids.
The Neapolitan spurilla, Spurilla neapolitana, can be found on oyster beds or in rocky areas. These nudibranchs have an appetite for stinging anemones, and can actually absorb their stinging cells. The long, feathery projections covering their body are a collection of stinging cells and algae that the creature absorbed from its prey.
Elysia subornata is a bright green to brown sea slug that lives in silty and muddy intertidal areas. We recently found this species at Bunche Beach feeding on green algae, its favorite meal. These nudibranchs will absorb the pigments of the algae that allow for photosynthesis, and use them to produce its own energy from sunlight. Imagine being able to eat your favorite plant, then use its leaves to make energy from the sun!
Sidegill sea slugs (Pleurobranchaea inconspicua) have gills that are visible along the sides of their body. This group of sea slugs is known for producing mantle secretions that contain neurotoxins as a defense against predators.
Now that you know Sanibel's waters are teeming with nudibranchs in all shapes and sizes, we hope you will keep an eye out for them, and please tell us about your finds!