Red Dendronotid

By Kailey Garrett

Common name:  Red Dendronotid

Scientific name:  Dendronotus rufus

Size range:  up to 28 cm (11 in)

Identifying Features:

Dendronotus rufus have rectangular bodies with cerata that branch out at the edges. Their bodies are generally white and often have colors on the ends of the cerata. They are usually red, dark brown, or a light pink. They are sometimes known as the Giant Red Sea Slug, because of their size.


The Red Dendronotid is usually found in the South Alaskan waters down to north Washington. They are mostly found in sub-tidal waters.


All known nudibranchs are carnivorous. Nudibranchs usually eat live prey such as soft corals, sea pens, and gorgonians, and will often starve to death in captivity without the appropriate foods.


There is no documented information on what hunts the Red Dendronotid, but generally certain fish, turtles, sea stars, and a few species of crabs prey on these animals.


Nudibranchs are hermaphrodites, and can mate with any member of their species. When mating, two nudibranchs come together side by side and pass sperm sacks through a tube on the right behind the head. After mating, they lay their eggs in a gelatinous spiral, near the organism that they eat. Nudibranchs can lay up to two million eggs depending on the species. Usually the eggs develop first into larvae, and then they drift down the ocean currents as plankton. Specific environmental conditions help the larvae to settle and change into the adult form. This process is extremely important because adult nudibranchs move slowly and cannot travel very long distances.


Lamb, A. and Hanby, B. P. (2005). Marine Life of the Pacific Northwest. Madeira Park, BC: Harbour Publishing.

Microcosm aquarium explorer (2008) Dendronotid Nudibranchs, retrieved December 10, 2012

Nudibranchs, Basic Nudibranch Taxonomy, retrieved December 10, 2012.

National geographic (June 2008) Living Color, Toxic Nudibranchs-soft, seagoing slugs-produce a brilliant defense.  Retrieved December 10, 2012.

Wikipedia (2 August 2010, at 07:46) Nudibranch, retrieved December 10 2012

Pacific Wingfoot Snail

Author: Shelbie Montagnaro

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

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Nothern Abalone

Author: Amy and Katherine Spanier

Common Name: Northern Abalone, Pinto Abalone

Scientific Name: Haliotis kamtschatkana

Size Range:
18cm (7in.) across

Identifying Features:
The Northern Abalone’s is the only species of abalone in Canada.  Its shell size is 18cm (7in.) across and is usually a reddish-brown and/or greenish colour. The inside of the shell is mostly white,  unlike other abalone that have many other colours inside the shell. In addition, it is oval shaped with 3-6 tubular projections (perforations) and has weirdly designed bumps and thick ridges on the shell. The gills draw water in through the anterior (head) end of the body and it leaves through these perforations in the shell.

The Northern Abalone can be found in Japan, Siberia, s.Alaska to n.Mexico, and in British Columbia, Canada. They are often found around kelp and they cling to rocks. The abalone can live in depths to 35m (116ft).

Food (Prey):
Abalone first start eating phytoplankton then move on to macro-algae and sometimes Giant Bull Kelp (Nereocystis luetkeana).  When they grow bigger, they start to eat drift algae. Abalones have a structure called a radula in their mouth which is like a ribbon lined with rows of teeth.  They use this to rasp algae off of rocks when they are feeding.

The animals that eat the Northern Abalone are sea stars, sea otters, fishes, crabs, and octopus. Its major predators are birds, minks, and humans (fishing industries). To avoid being eaten by these predators, this creature hides in between rocks, its foot holds onto rocks, and the algae that grows on its shell helps with its camouflage. The shell is strong and is very difficult to pry off of rocks.

Life Cycle:

Northern Abalone undergoes sexual reproduction and they send out their gametes into the water.
The fertilized eggs grow into free swimming larvae and disperse all over the sea.  In two weeks or less, they attach themselves to a rock, on which they stay for the rest of their lives. The young ones size depends upon how much food they can find the first year.  During this time the shell usually grows to 1/2″ (10 mm).

Northern Abalone in British Columbia:
According to Louis Gosselin who studies abalone at Thompson Rivers University in Kelowna, BC, the Northern Abalone “is the only species of abalone living in Canada, and it is the only marine invertebrate in Canada to be listed as endangered”.  This is due to overharvesting when they were open to collection and then to poaching once they were protected.  This as well as environmental changes has contributed to the abalone’s decline.  The fisheries was closed in 1990 and the Northern Abalones are now currently protected under the Species at Risk Act (SARA) and the Fisheries Act for the harvesting of them.  The Northern Abalone grows slowly but the Red Abalone (Haliotis rufescens) which is a faster growing species is being farmed and in just three years they are at a marketable size for selling.


Photos are courtesy of Louis Gosselin, Dept. of Biology Science, Thompson River University, Kamloops, BC, Canada


Andy, L and Bernard, H. (2005) Marine Life of the Pacific Northwest: a photographic encyclopedia.
Library Archives Canada in Publication

Georgia Strait Alliance (2012) Georgia Strait Alliance: Caring for Our Coastal Waters, Species at Risk Profile: Northern Abalone. Retrieved February 23, 2012 from

Jan A. Pechenik (2005) Biology of the Invertebrates fifth edition

Mc Graw Hill Higher Education

Rick M. Harbo, (1997) Shells & Shellfish of the Pacific Northwest
Maderia Park, British Columbia: Canadian Cataloguing in Publication Data

McDougall, P.T., Ploss, J. and Tuthill, J. (2011) International Union for Conservation of Natural Resources. Haliotis kamtschakana Retrieved February 23, 2012 from

Olin, Thomas and Lockhart, Brennan (2011) – Personal Communication.  Thank you to Thomas and Brennan for preliminary work and contacting Louis Gosselin at Thompson River University in Kamloops, BC.

The Eight Continent Scientific + Graph Services (2009) Save Our Abalone. Retrieved February 13, 2012 from

Vancouver Aquarium (2011) Vancouver Aquarium: Ocean Wise. Retrieved April 4, 2012 from

sea lemon extra smallMonterey 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.

sea lemon diagram 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

Hooded Nudibranch

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.

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Gumboot Chiton

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.

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Common name: Golden Dirona

Author:  Samantha Claver

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

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Giant Pacific Octopus

Author: Stephanie Hurst

Common name: Giant Pacific Octopus

Scientific name: Enteroctopus dofleni

Size Range: 3-5 meters and averaging 50kg (110lbs)

Identifying Features:

Giant Pacific Octopuses  as their name implies are found in the northern part of the Pacific Ocean. They are spotted anywhere from California up to Alaska and across to Japan.  They prefer living in the depths of temperate ocean water.  Similar to all octopuses Giant Pacific Octopuses are invertebrates, with distinct large bulbous heads, eight arms, and a beak made of calcium carbonate.  What sets them apart is their colouring and size. Giant Pacific Octopuses can grow to a length of 5 meters and weigh up to 50 kilograms. Generally they are a reddish-brown colour, they are capable of changing the texture of their skin and they have specialized cells call chromatophores that allow them to change their colour making it easy for them to camouflage into any surrounding.


The Giant Pacific Octopus’ preferred prey includes crabs, lobsters, shrimp, and clams. Time to time in some situations octopuses have been known to attack and eat sharks, and even other octopuses!  Octopuses are nocturnal hunters, and very stealthy.  Using their highly developed eye sight they look for motion from prey, when the prey ventures too close or the octopus get close enough it will ambush the prey using its strong arms to prevent it from escaping.  When eating, the octopus uses it strong beak to rip apart prey, and drill or bite into shells.


Even though the octopus seems invincible it does have some predators. Animals who like to make an octopus into a meal are large fish such as halibut and lingcod, as well as some marine mammals like sea lions and dolphins. There are two main ways octopuses can escape from predators, one way is through jet propulsion, giving them a burst of motion away from a predators. The second way is by releasing ink which temporarily blinds and confuses the predators.

Life Cycle (see the image below):

On average Giant Pacific Octopuses live 3-4 years. Females die directly after they have finished laying and guarding to their egg however males live a slightly longer time. Octopus reproduction starts when a male uses a specialized tentacle to pass two spermatophores (sperm packages) to the female. Once given the sperm the female stores the package until she is ready to fertilize the eggs.  Before a female is ready to fertilize the eggs she has to find a suitable den. This search can take the future mother up to one month! Once the perfect place is found the female shuts herself in using rocks. From there she fertilizes each egg and gathers them in bundle of approximately 200. She hangs each group of eggs from the ceiling of the cave. This is a long process because on average a female octopus can lay up to 50,000 eggs.  The incubation time for octopus eggs are six and a half months.  During this time the female stays in the cave, not even leaving to eat, attending to the eggs by constantly blowing oxygenated water on to them. When the baby octopuses hatch they are referred to as paralave. These tiny juveniles swim up to the surface joining other zoo plankton and spending weeks feeding on tiny phytoplankton. Once they have developed enough mass they descend to the benthic zone.  As for the mother, she waits until all the eggs have hatched then emerges from the cave and dies shortly afterwards due to the starvation she endured during the months she spent devoted to tending her eggs.

Photos by S. Hurst and A. Rutledge

Illustration of Octopus life cycle by Tatiana Neder


B.C. Royal Museum. (2010). Giant Pacific Octopus. B.C. Royal Museum. Retrieved January 4, 2012

B.C. Royal Museum. (2010). OCTOPUS REPRODUCTION. B.C. Royal Museum. Retrieved January 4, 2012

MLA Citation. ” Giant Octopuses, Enteroctopus dofleini at”. 4 January 2012.

National Geographic. (2012). Giant Pacific Octopus Enteroctopus doflein. National Geographic. Retrieved January 4, 2012.

SHIM. (unknown). Species and Habitat Outline; Giant Pacific Octopus. SHIM. Retrieved January 4, 2012

The Frosted Nudibranch

by Elias and Jesse

Common name:  Frosted Nudibranch

Scientific name: Dirona albolineata

Size range: up to 180mm (18cm) in length

Identifying Features

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.

Life Cycle

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.

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Blue Top Snail

Author: Alisha Carey

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

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