Clown Nudibranch

Common Names: Clown Nudibranch

Scientific Name: Triopha catalinae

Size Range:

Clown Nudibranch (Triopha catalinae)

Video by Isobel Austin and D. Young

Please visit back soon – more information on this nudibranch will be posted soon.

Shag Mouse Nudibranch

Author: Breyn Banks

Common Names:  Shag Mouse Nudibranch, Shag Rug Nudibranch,  Shag Nudibranch.

Scientific Name: Aeolida papillosa

Size Range: 10 to 12 cm in length.

Little is known about the Shag Mouse Nudibranch (Aeolida papillosa). They belongs to the group of soft bodied marine gastropods known as the nudibranchs. They range from 10 to 12 cm in size depending on what part of the world they live in and are known by many names such as The Shag Mouse Nudibranch, Shag Rug Nudibranch, or just simply the Shag Nudibranch. They get these names from the shag-esk ceratas running over its body. The certas themselves do not split down the centre or spread apart which is counter to a lot of other shaggy nudibranchs making them easily identifiable if you are looking for them.
The shag rug nudibranch lives in the intertidal zones of the atlantic and pacific ocean. The deep water species which live in the pacific northwest live at depths of 500 meters deep, but some species have been found as deep as 900 meters. They are mainly found in the Circumboreal, the South of France, the South of Maryland, Argentina,  the Falkland Islands, The Sea of Japan, Alaska, and Chile. The shagmouse nudibranch lives in many different habitats and parts of the world.
The shag mouse nudibranchs known diet is very simple. They feed on various sea anemones. The shag mouse nudibranch has a very interesting defence system that goes with its simple diet. When they feed on the various anemones they store the preys stinging cells (cnidocytes) in its cerata for defence.   They also will change colour based on the colour of food they ate much in the way that a flamingo is the same colour of the shrimp it eats.
The specific predators of the shag mouse nudibranch are unknown but if it is similar to other nudibranchs then crabs and sea stars would be among the most likely predators.
The shag mouse nudibranchs reproduces similar to other nudibranchs. They are hermaphroditic, containing gonads that produce both eggs and sperm.  Individuals will transfer sperm and the eggs are laid in a gelatinous spiral.
Johnson, P.M & Willows, A.O.D, (1999) Defense in Sea Hares (Gastropoda, Opisthobranchia, Anaspidea): multiple layers of protection from egg to adult. Marine & Freshwater Behaviour & Physiology, 32: 147-180.
Hildering, J. & Miller, G., 2007 (Jul 10) Cadlina luteomarginata? being eaten by a seastar. [Message in] Sea Slug Forum.Australian Museum, Sydney. Available from  
The Reproductive Systems of the Nudibranchia (Gastropoda, Opisthobranchia): Comparative Histology and Ultrastructure of the Nidamental Glands with Aspects of Functional Morphology

Photographs by D. Young

Zebra Leafslug, Taylor’s Sea Hare

Author: Rubin Cheney

Common name: Zebra Leafslug, Eelgrass Sea hare, Taylor’s Sea Hare

Scientific name: Phyllaplysia taylori

Size range: Up to 8cm (3.2 in) long

Identifying features

The Zebra Leafslug can be identified by its vibrant green and dull white stripes that may be outlined in black that run down the length of its body.  Though it may grow to 8cm in length they are often found much smaller (3 to 4cm).  There are two colour variations, one that is a deep green and another form that is yellow.  They are most easily found along the blades of eelgrass (Zostera marina) in the summer, where they can safely hide from predators and feed.  The sea hares are named for the long tentacles (rhinophores) that make them look like the ears of hares.


The Zebra Leafslug can be found along the Pacific West Coast, from British Columbia to Mexico.  They are most commonly found in the Northern Pacific around B.C. at a depth of around 5.5 meters and are almost exclusively found on eelgrass (Z. marina).


In general Sea slugs can be both carnivorous and scavengers, but the Zebra Leafslug almost solely grazes upon various species of sponges and diatoms that grow on the surface of eelgrass.


Sea hares such as the Zebra Leafslug are hermaphrodites, producing both eggs and sperm.

Photograph by Nicole LaForge


Lamb, Andy and Hanby, Bernard P. 2006. Marine Life of the Pacific Northwest. Harbour Publishing, British Columbia

Rudman, W.B (2005). Retrieved January 21st 2013 from

Common Name:  Sitka Periwinkle

Author:  Bea Wicker

Scientific Name:  Littorina sitkana

Size Range:  Up to 2cm (0.8 inches) long

Identifying Features:  The Sitka Periwinkle generally has a brown or grey shell, which is sometimes striped. They can close themselves inside their shells with a door, called an operculum. They slide around in their own mucus using their muscular foot. They have little eyes, antennae, and a mouth, which is full of tiny razor sharp teeth.

Habitat:  Sitka Periwinkles attach themselves to pilings, mangroves, seaweed, rocky shorelines, and beneath boats and docks using mucus. They are one of the few sea creatures that can breathe air, and when the tide is low, they close themselves up into their shells to prevent drying out.  Despite this ability many end up dying due to drying out especially when exposed to high temperatures. They live on the Pacific Ocean, from Alaska to Baja, and also on the Atlantic coast.

Food:  Sitka Periwinkles are vegetarians. They feed mainly on filamentous algae but also eat films of diatoms, lichens and Rockweek (Fucus gardneri) . They scrape food off of surfaces with a hooked, chainsaw like structure of teeth called a radula. Impressively, they can replace up to seven rows of teeth daily! Most Sitka Periwinkles only eat every 2-3 weeks.

Predators:  Many animals prey on the Sitka snail, such as sea stars, crabs, sea anemones, and various water birds.   One study found the main predators to be the Red Rock Crab (Cancer productus) and the Pile Perch (Rhacochilus vacca). To protect themselves, the snails close themselves into their thick armor like shells.  Many hermit crabs will use the empty shell of the Sitka Periwinkle as their home.

Life Cycle: Once yearly, males seek out mates. Often they can’t tell the difference between females and other males, and sometimes two males can be seen fighting, only to discover that the supposed female is in fact another male.  Once fertilized by the male females lay 50-400 eggs in mucus bundles in tide pools. Once hatched, larvae are washed out to sea to grow. Young periwinkles look like miniature adults.

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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.  It smells like watermelon and is produced in glands to act as a deterrent to predators.

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 planktonic 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 (and in more recent publications “the wandering meatloaf”)

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 central coast of California up to Alaska, across the Aleutian Islands and down to southern Japan.

Food: Gumboot Chiton are herbivores and eat algae, sea lettuce and seaweed. They feed nocturnally with a radula.  The radula contains two rows of teeth that scrape the surface of rocks for algae, they resemble a sort of zipper.  The teeth of the radula are one of the hardest known materials produced by a living creature.

Predators: Various bird species such as gulls will feed on Gumboot Chiton and occasionally octopus,  Sea Otters and sea stars. The chiton can roll up into a ball to protect itself.

Life Cycle: Gumboot Chiton can live over 40 years and are dioecious (have male and female reproductive organs in different individuals). To reproduce the male gumboot chiton releases a cloud of sperm into the water.  The female releases a long strand of eggs that are then fertilized by the sperm. The fertilized egg will develop into a trochophore larva and then metamorphose into a young chiton.


Gumboot Chiton Cryptochiton stelleri, OceanLink. Retrieved from on June,5,2010

Kozloff,E(1993). Seashore life of the northern pacific coast. An illustrated guide Northern California, Oregon, Washington, and British Columbia. Seattle, Washington: University of Washington press.

Gumboot chiton, Kelp Forest, Invertebrates, Cryptochiton stelleri. Monterey Bay Aquarium, California. Retrieved June 7, 2010 from

Mason, S. (January 2002). Taxonomy: Gumboot Chiton. Race Rocks Ecological Reserve/ Marine Protected Area. Retrieved June 7, 2010 from