Nudibranchs, or 'sea slugs', display a variety of colors and patterns, allowing some them to match their environment closely. The nudibranch has a shell early in its life, which is soon lost. It has few predators. Many have chemical defenses or discharge stinging cells (nematocysts). All nudibranchs have a pair of projections near the head called rhinophores, which help them detect chemicals in the water, some of which can lead to a food source. |
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Opalescent Nudibranch | (Hermissenda crassicornis) | |
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Description: Colorful mollusk without a shell. Most species absorb oxygen through unusual appendages, called cerata, that grow from their back. Body translucent white with cerata tipped with orange.Two white smell-sensing rhinophores extend from the head. Found in eelgrass beds and rocky beaches. Look for this animal on the undersides of older moon snail sand collars. Length up to 2 in (5 cm). |
Food: Omnivorous. | |
Reproduction: Most are hermaphrodites, having both male and female reproductive organs. Eggs are deposited in ribbon-like clusters. | |
Fun Facts: This species has mouth parts adapted to separate the different layers of a moon snail sand collar so it can feast on the tiny eggs. | |
Shaggy Mouse Nudibranch |
(Aeolidea papillosa) |
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Description: Colorful mollusk without a shell. Most species absorb oxygen through unusual appendages, called cerata, that grow from their back. Gray-brown body with numerous cerata. Found on rocks, pilings, eelgrass beds, and mudflats. Length up to 2.5 in (6 cm). |
Food: This sea slug eats the tentacles of sea anemones. | |
Reproduction: Most are hermaphrodites, having both male and female reproductive organs. Eggs are deposited in ribbon-like clusters. | |
Fun Facts: Immune to the anemone sting, this species can consume 100 percent of its body mass per day. This species is found worldwide. | |
Frosted Nudibranch |
(Dirona albolineata) |
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Description: Colorful mollusk without a shell. Most species absorb oxygen through unusual appendages, called cerata, that grow from their back. Opaque with leaf-like cerata edged in brilliant white. Length normally about to 1.5 in (4 cm), but can grow to 7 in (18 cm). |
Food: Feeds primarily on small snails which it breaks open with its small teeth. | |
Reproduction: Most are hermaphrodites, having both male and female reproductive organs. Eggs are deposited in ribbon-like clusters. | |
Fun Facts: This species is also found in Japan and Russia. | |
Brown-Striped Nudibranch |
(Armina californica) |
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Description: Colorful mollusk without a shell. Lacks cerata. Instead has gill-like structures under a flap along its margins. Flattened leaf-shaped body with thin brown and white stripes. Length up to 3 in (8 cm). |
Food: Feeds on orange sea pens. | |
Reproduction: Most are hermaphrodites, having both male and female reproductive organs. Eggs are deposited in ribbon-like clusters. | |
Fun Facts: This sea slug is most commonly found out on the sandy tidal flats at a very low tide. | |
Barnacle-Eating Dorid |
(Onchidoris bilamellata) |
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Description: Color is a mixture of browns and cream. Blunt-tipped projections cover entire body. Simple gills form a broad horseshoe. Up to 1 in (2 cm) long. Found on rocks or attached to clumps of seaweeds or feather duster tubeworms. | |
Food: Barnacles are the only food of the adults. This nudibranch sucks out the barnacle's body contents with a special pumping mechanism. | ||
Reproduction: Individuals come together in large groups to mate and lay eggs in shallow water. | ||
Fun Facts: This dorid is found on both sides of the Atlantic coast also. | ||
Sea Lemon |
(Doris montereyensis) |
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Description: Colorful mollusk without a shell. Lacks cerata. Oval; pale to deep yellow with brown spots on back. A pair of pointy rhinophores at the front end, and a frilly gill cluster at the rear. Found on rocks and pilings, anywhere encrusting sponges may be found. Length up to 2 in (5 cm). |
Food: Feeds on a variety of encrusting sponges. | |
Reproduction: Most are hermaphrodites, having both male and female reproductive organs. Eggs are deposited in ribbon-like clusters. | |
Fun Facts: This species has a citrus or fruity smell which may help it repel intruders. | |