Pacific Wingfoot Snail
Common names: Pacific Wingfoot Snail, Sea Butterfly
Scientific name: Gastropteron pacificum
Size Range: to 33mm (1.3 inches) in length
Identifying Features: The Sea Butterfly has a shell-like appearance. Its foot and swimming lobes are a yellow-ocre color and it has clusters of red-purplish dots all over its body. When viewed up close the main body appears translucent.
Habitat: You will often find young individuals of Gastropteron pacificum swimming erratically in open water using a flapping motion of their lateral foot lobes. They can be found from the surface of the water to as deep as 30 meters below sea level from Alaska all the way along the western coast to San Diego, California. Despite the pelagic nature of the young of this species it lives mostly a benthic life. It moves about on the sea floor in soft sediment and looks much like a regular snail with its lobes folded over its body.
Prey: Plankton is the only known prey of the sea butterfly, although there is research being done to find other food sources of this species.
Predators: The only known predator that has been recorded is the Cephalaspidian mollusk Navanax. Contact with predators can induce G. pacificum to begin swimming away using its lateral foot lobes.
Pacific Wingfoot Snail at Victoria High School: A Pacific Wingfoot Snail was collected in open water in Cadboro Bay in a plankton tow in October of 2011. It was kept in our Seaquaria in the classroom for 5 months. During this time it was rarely observed swimming though it did swim on occasion when it was disturbed. It was not directly observed feeding but may have fed upon frozen brine shrimp used to feed the other aquarium inhabitants.
Video by Shelbie Montagnaro and D. Young
Photos by D. Young
Monterey Sea Lemon
By Anna Stürgkh
Common name: Monterey Sea Lemon, Sea Lemon
Scientific name: Doris montereyensis (Archidoris montereyensis)
Size range: 4.4 cm (1.7 inches) to 15 cm (6 inches) in length and 4 to 5 cm in width.
Animated GIFs by Lia Glidden
Identifying Features: The Monterey Sea Lemon (Doris montereyensis) is a distinct looking nudibranch with its bright yellow colour however it is easy to confuse with the Noble Sea Lemon (Anisodoris nobilis). Both have a similar shape, are bright yellow, have distinct tubercles (bumps) on their dorsal side, have feathery gill plumes, and may have a varied pattern of dark spots on their dorsal surface. There are a number of features that can be used to tell them apart. D. montereyensis is often described as having a “dingy” colour and is the one that has dark spots on the tips of the tubercles. A. nobilis in contrast is described as having a “clean” colour. It generally has a white gill plume, particularly on the outer edge of the plume, and the dark spots if present are only found between the tubercles.
Habitat: The Monterey Sea Lemon is commonly found on the west coast of North America. Its habitat reaches from southern Alaska to southern California. It can be found intertidally and can live in depths of up to 256m. This nudibranch prefers shaded and rocky regions. It is often found in areas with Bread Crumb Sponges.
Food: The Monterey Sea Lemon preys only on sponges, such as Haliclona panicea, which are commonly known as the Bread Crumb Sponges. These sponges provide the sea lemon with its yellow colour (it is not surprising that the similarly coloured A. nobilis also feeds on the Bread Crumb Sponge). The nudibranch uses its rough tongue (radula) to rub small pieces off the sponges.
Predators: Similar to other nudibranchs the bright yellow colour suggests that the Monterey Sea Lemon has chemical defenses and is a warning to predators that they should be avoided. The predation on this species is not well known. In captivity in our school aquarium a Pacific Spiny Lumpsucker took a bite out of the Monterey Sea Lemon but promptly spat it out.
Life Cycle: The Sea Lemon is a hermaphrodite. It reproduces throughout the year. It lays several eggs in capsules and the capsules come together to form a yellow chord, which can keep up to 2 million eggs. After the eggs are laid, the sperms that are stored in a “seminal receptacle” become agile and fertilize the eggs. The larvae hatch after about 23 days.
Photographs by Anna Stürgkh, Erin Pringle and D. Young Read more
By Maggie Ikeyima
Common names: Hooded Nudibranch and Lion Nudibranch
Scientific name: Melibe leonine
Size range: Up to 10cm long, 2.5cm wide and 5cm across oral hood.
Identifying Features: The Hooded Nudibranch can be up to 10 cm long, 2.5cm wide and 5cm across the expanded oral hood. The Hooded Nudibranch is a translucent white, yellow, orange, or greenish organism. It has a quite noticeable round oral hood for what could be seen as a “head”. Another feature to note, is that they are more gelatinous than a typical sea slug. When the hooded Nudibranch is taken out of water it gives off a sweet fruity aroma.
Habitat: Hooded Nudibranchs have been seen to live near low tide waters and in kelp forests in deep waters. They are commonly found clinging to eelgrass with their large foot, but they are also found on different seaweeds such as the blades of the Giant Bull Kelp. It is typical to find them from 0- 328m in depth. From what I have seen in the aquarium, the Hooded Nudibranch does not seem to be bothered by sharing its habitat with the many other marine organisms.
Food: The Hooded Nudibranch is a carnivore. They attach themselves to the under-water grasses, for example, and once the they feel their prey the fringes of the tentacles overlap, which then holds the prey and forces it into the mouth. The food then moves through the esophagus to the stomach. The Hooded Nudibranch constantly feeds as long as food is present. They eat small fish, small molluscs, and other invertebrates such as copepods, and zooplankton.
Predators: Predators of the Hooded Nudibranch would include fish, kelp dwelling crabs and sea stars. A quite unique defence for the Hooded Nudibranch is how they are to drop one of their cerata to distract the predator for just enough time to get away. Hooded Nudibranchs are quite entertaining swimmers as they flex their body in a side to side rhythm upside down to escape.
Life Cycle: Hooded Nudibranchs are hermaphrodites. This means that each one has both male and female reproductive organs. When reproducing, two would fertilize each other and then lay their eggs on, most commonly, kelps. Hooded Nudibranchs internally fertilize which is quite rare. Their eggs are tightly coiled in cream or yellow-coloured coil or wave like folds. Hooded Nudibranchs live for approximately a year and die once they lay their eggs.
By Adam Kitzler and Niko Kruzel
Common Name: Gumboot Chiton
Scientific Name: Cryptochiton stelleri
Size Range: Up to 13 inches (33cm) in length
Identifying features: Gumboot Chitons have an orange to yellow underside and their skin is normally dark. Unlike normal chitons the eight bony plates on its back are concealed. The Gumboot Chiton is the largest chiton in the world and has no eyes or tentacles; but sensory cells to help it navigate. It is very slow.
Habitat: Gumboot Chiton live on shallow rocks, where they can stick using there large foot so they don’t get swept off by the tide or large waves. They exist from the coast of California up to Alaska and down to Japan.
Food: Gumboot Chiton are herbivores and eat algae, sea lettuce and seaweed. They feed nocturnally with a radula. Radulas are two rows of teeth that scrape the surface of rocks for algae, they resemble a sort of zipper.
Predators: Lurid Rocksnails and Seagulls will feed on Gumboot Chiton and occasionally Sea Otters and Sea Stars. The Chiton can roll up into a ball to protect itself.
Life Cycle: Gumboot Chiton can live up to 20 years and are dioecious. To reproduce the male gumboot chiton releases a cloud of sperm witch is the taken by a female, she them releases a long strand of fertilized eggs that are encased in jelly.
Common name: Golden Dirona
Scientific name: Dirona pellucida
Size Range: up to 12 cm (5 inches) long
Identifying Features: Dirona pellucida belongs to the Nudibranchia family. It has an eye-catching orange to red-orange color and has white specks on the tips of its cerata (the spiky leaf-shaped structure that covers its back). The cerata aids in the nudibranch’s respiration, but it also is used for defence. Unlike the D. pellucida’s back, its stomach is smooth and almost translucent.
Habitat: Golden Dironas live in the intertidal zones of the oceans, to depths of 60 meters. They can be found in tides from North Sound, Alaska to Puget Sound, Northern Washington, across the Bering Sea until the eastern seas of Japan, Korea and Russia.
Food: Golden Dironas are ectoproct feeders, specifically the bryozoan Bugula pacifica. We sometimes find them on top of sea sponges, not feeding from them but hunting for bryozoans from on top of them. Golden Dironas at times are spotted to be eating other things besides bryozoans as they sometimes feast on hydroids and ascidia.
Predators: The Golden Dirona has a lot of predators. Due to its flashy colour it attracts attention very easily, and its lack of a protective shell makes it vulnerable to predators. Its enemies range from crustaceans to birds and large fishes, depending on where it is located. Like many nudibranch’s the bright coloration of D. pellucida likely indicates to predators that it is toxic. If attacked they can detach the cerata from their back to distract the predator while they attempt to get away. As a result some individuals may have a large number of their cerata missing.
Life Cycle: D. pellucida is a hermaphrodite; it has both male and female organs. Once ready to reproduce they seek out to find partners, but despite having both organs having them self-fertilize is very rare. Instead they fertilize each other’s eggs with each other’s sperm. They then lay eggs in an egg ribbon. The eggs would then become trochophore larvae and then develop into vertilar larvae. This is when they hatch and leaves the security of where its parent laid it. The vertilar larvae would then undergo metamorphism and turn into a juvenile. It looks exactly like an adult minus the size and the fact that it isn’t sexually mature.
Behaviour: Many species venture out onto the surface of tide pools when the tide is out and the pools are very calm. They are likely just cruising around looking for food. They can easily hang by surface tension because they have almost neutral buoyancy (no shell to drag them to the bottom).
Photography by Samantha Claver
The Frosted Nudibranch
by Elias and Jesse
Common name: Frosted Nudibranch
Scientific name: Dirona albolineata
Size range: up to 180mm (18cm) in length
Frosted Nudibranchs are soft bodied organisms similar to slugs. In the general, nudibranchs are often referred to as sea slugs. Frosted Nudibranchs can range anywhere from 20- 600mm long, but their most outstanding, and identifiable feature, is the frosty white tips on the cerata on their back. They come in a wide variety of colours, including mauve and peach, and for the most part, they’re translucent. The Frosted Nudibranch is known to shed its cerata when stressed.
The Frosted Nudibranch thrives along the shores of Japan, Siberia, and Southern Alaska, to Southern California. It is found intertidally and up to 37m deep.
Most sea slugs have very specific feeding needs, thus making them difficult to keep in aquariums. The Frosted Nudibranch has powerful jaws enabling it to crack open snail shells. This nudibranch has a vast selection of prey including arboresent and foliose bryozoans, hydroids, small prosobranchs, crustaceans, and ascidians.
Nudibranchs are hermaphrodites. They have both male and female reproductive organs. In most cases, two separate organisms will exchange sperm. But there is a potential for self fertilization. Once the eggs are fertilized, they are laid in large amounts, often very close to a food source. Once hatched, they are in the trocophore larvae stage, characterized by a round shape, and numerous sensory and defensive hairs. The veliger larva stage is the stage in which young nudibranchs hatch. Eventually they abandon the water column, and travel to the bottom, becoming benthic. It is at this point, where they undergo metamorphosis, and become juveniles.
Blue Top Snail
Common name: Blue Top Snail
Scientific name: Calliostoma ligatum
Size range: up to 2.5 cm (1 inch) in diameter
Identifying Features: The Blue Top Snai (Calliostoma ligatum) is part of the Callistomatidae family. It has a brown shell with tan to orange spirals. Its inner layer its pearly blue, and the foot of the snail is orange. When the outer layer of the shell is worn away the top of the shell (or the whole shell) may also look blue which is why it is called a Blue Top snail.
Habitat: Blue Top Snails are found in tide pools or up to 30 meters deep in the ocean. They can be found from Alaska to California. Blue top snails keep to rocky areas and kelp beds.
Food: C. ligatum eat a variety of algae and kelp. It eats by using its radula teeth (a ribbon with rasping teeth.)
Predators: The Blue Top snail protects itself by hiding within its shell. Some of their predators include shore birds, fish, crabs and other snails.
Life Cycle: In general, snails are considered sexually mature by the time they are one year old. The C. ligatum has both female and male organs. It produces eggs which it fertilizes inside. Then they release the eggs and they are attached to rocks and seaweed but some eggs can be found in the sand.
Photos by D. Young
Interesting resources for research and photographer credit
Victoria High School
1260 Grant St.
Victoria. BC, Canada