Octopus Skin Tricks

Author: Ella Cholette

In nature, it should be known that octopus have the most remarkable brains. They do have nine after all. Not only do they possess the power to perceive, reason, and think, but they are great escape artists with a mastery of disguise… And yet, the question is still asked: how do these creatures so brilliantly hide in their environment?

An octopus is a soft-bodied, eight-limbed mollusc that belongs to the cephalopoda class, which includes squid, cuttlefish, and nautiloids. Like other cephalopods, the octopus is bilaterally symmetrical: it has two eyes, one beak, with a mouth in the center of the eight tentacles.


Ruby Octopus  (Octopus rubescens)

Learn more about this species here.


The chromatophores of a cephalopod

Layne, M. (n.d.). [Photograph found in Seattle, Washington]. Retrieved January 30, 2021, from https://commons.wikimedia.org/wiki/File:Chromatophores.jpg (Originally photographed 2007, November 24)

Each of the octopus’ skin cells contain a tiny packet of pigments called chromatophores. These packets of pigments are responsible for the remarkable colour transformations octopods are famously known for. At the center point of each chromatophore is an elastic sac filled with red, yellow, blue, brown, and black pigments – resembling tiny, dye-filled balloons – that are surrounded by an intricate network of nerves and muscles that work to expand or contract the sac. When the octopus wants to change its colour, these radial muscles pull the sac open, forcing the pigment to expand underneath the skin and thus making the colours more visible. The chromatophores in the octopus can be opened quickly because they are being controlled neurally, meaning the octopus can change colours faster than any other colour-changing animal.


The skin around the eyes of a frightened Ruby Octopus becomes darker to make the eyes, and the octopus, appear larger

Although these colour changes may be voluntary, they are also strongly associated with the octopus’ behaviourally diverse moods. For example, an angry octopus will turn bright red, while a frightened one will turn pale white.

The most obvious reason why a soft-bodied animal would change colour is to hide from predators – something the octopus is very good at. Yet, some use colour change as a warning to their predators or any other marine animal that threatens them. An example of this is the blue-ringed octopus, hapalochlaeuna lunulata. The Blue-Ringed Octopus is extremely venomous, and when provoked, iridescent blue rings appear over their bodies as a way to warn others of its toxicity.  Visit the Blue-Ringed Octopus page for more information on this species. 

As well as changing colour, the skin of an octopus can also change texture in seconds: creating fine bumps or high ridges that are used to camouflage with their surroundings. Octopus tend to match their texture with rocks, corals, and other objects nearby that will help them hide from oncoming predators as well as their own potential prey… but, how are they able to do this? With the bad business of papillae!! Papillae are sections in the skin that can be transformed to change texture using small muscle contractions, of which they have three sets. One set is shaped in concentric circles to lift the skin vertically away from the body, another pulls this form together to determine what the shape will be, and the third and final set of muscles pull the raised section back down towards the surface. By having the ability of controlling the size of papillae on their skin, octopuses can create unique textures that result in a disguise that nearly makes them invisible.


The raised papillae of a Giant Pacific Octopus (Enteroctopus dofleni) – look at all the ridges!

Learn more about this species here.

Photo by S. Hurst and A. Rutledge


Ruby Octopus

The reason why octopus are so interesting to many is the fact that they are capable of immediately altering their bodily shape. Although the individual components of octopus’ altering abilities are relatively well-known, how their brains are able to process the visual information around them through their extremities, then send out the correct commands to their camouflaging skin, is something extremely mysterious, and only makes them even more fascinating.

The video on the right shows the diverse colour tricks of Vic High’s octopus “Seamus” and her eventual release back into Saanich Inlet.

References

Gilmore, R. (n.d.). Cephalopod Camouflage: Cells and Organs of the Skin. https://www.nature.com/scitable/topicpage/cephalopod-camouflage-cells-and-organs-of-the-144048968

Harmon Courage, K. (2013). Octopus! The most mysterious creature in the sea. New York, New York: Penguin Group.

How octopuses don’t tie themselves in knots. (2014). Science and Children, 52(1), 12. https://link.gale.com/apps/doc/A382255974/SCIC?u=61vhss&sid=SCIC&xid=bb47faa0

Photos of Ruby Octopus by D. Young

Blue-ringed octopus (Genus Hapalochlaena)

Author Marco Joly

Photos by Barbara Moll

Characteristics  The Blue-ringed octopus is one of the smallest octopi, with a body length of up to 5 cm and arms up to 10 cm. It weighs from 10 to 100 grams. The skin is a light beige colour with brown spots, the neon blue rings appear on the skin when the octopus is frightened or agitated (for more information on octopus skin visit Octopus Skin Tricks)

Habitat  The Blue-ringed octopus lives in the benthic realm down to 20m deep. It lives among reefs or rocky areas, hiding in crevices and shells, for it is quite small. They live in the waters from Japan to Southern australia, and Sri Lanka to Papua New Guinea.

Hunting  Prey of the Blue-ringed octopus are small crustaceans, including crabs, shrimp, and small fishes occasionally. The octopus pierces through the victims shell with its beak prior to releasing venom from its salivary glands. The octopus’s greatest predator is the Moray eel.

Venom  The Blue-ringed octopus is well known for being one of the deadliest marine creatures, for using tetrodotoxin, also found in pufferfish. This toxin is produced by bacteria in the octopus’ salivary glands. Tetrodotoxin is a neurotoxin that stops nerves from firing by blocking ion channels. The venom is strong enough to kill a human within minutes.

Reproduction  The entire life cycle lasts only 7 months. After copulation, it takes a month for the eggs to be laid. The female carries her clutch of eggs under her skirt throughout the next 2 months while still mobile. When the eggs hatch they don’t become planktonic, they assume a benthic lifestyle immediately, which speeds up development. Within a week of hatching, the juveniles start eating bits of crab hunted by their mother. Within a month of hatching they hunt and kill their own prey. 4 months after hatching they become mature.

References

Greater Blue-ringed octopus. (n.d.). In Aquarium of the Pacific. Retrieved from https://www.aquariumofpacific.org/onlinelearningcenter/species/greater_blue_ringed_octopus1

Ray, K. (n.d.). Hapalochlaena lunulata. In Animal Diversity Web. Retrieved from https://animaldiversity.org/accounts/Hapalochlaena_lunulata/

Southern Blue-Ringed Octopus (n.d.). In Oceana. Retrieved from https://oceana.org/marine-life/cephalopods-crustaceans-other-shellfish/southern-blue-ringed-octopus#:~:text=The%20southern%20blue%2Dringed%20octopus,crustaceans%2C%20including%20shrimps%20and%20crabs

Tranter, D.J., Augustine, O. Observations on the life history of the blue-ringed octopus Hapalochlaena maculosa . Marine Biology 18, 115–128 (1973). https://doi.org/10.1007/BF00348686

By Cole Quinton

Grab your magnifying glass, your snorkel and start regulating those oxygen tanks as we dive into the open ocean and explore the world of the Glaucus atlanticus where we meet the little beauty that is the world’s only underwater dragon. If you are in the middle of the Atlantic, Pacific or Indian ocean and you have an extremely efficient magnifying glass and calm waters, then you may be lucky enough to spot a Blue Dragon floating along the surface or nearby with the help of the air bubble it has stored in its stomach, or if you are a beach goer then you may be unlucky enough to run into a “blue fleet” (a group of Blue Dragons which were taken ashore shore). How do you know what a Blue Dragon looks like? It has a silvery grey colour on its dorsal side facing the waters below because it floats upside down to blend in with the light from the sea surface, concealing it from predators below (Loggerhead sea turtles being the only known marine predator). The Blue Dragon is dark and pale blue on its ventral side with blue stripes on its head, they use the blue colour of the ocean to camouflage into their surroundings. It has a flat, tapering body and 6 appendages that branch out into rayed, finger like cerata, and is only a miniscule 3 cm in length. 

Though the Blue Dragon lacks in stature it is not something to take lightly, they take on fearsome beasts of the sea, like a mighty Man of War (a strange creature that looks like a jellyfish but actually belongs to the siphonophores) and other creatures such as blue bottle jellyfish, and some Blue Dragons have even been documented to be cannibalistic, but only when faced with an injured or recently deceased fellow Blue Dragon. To appreciate the Blue Dragon’s defence we need to first understand the defence of the creatures that it feeds on, the Man of war, one of the oceans creatures with one of the most painful and deadly stings, uses cnidocytes that are cells that shoot off threadlike, often toxic, tubule inside the cnidocyst. When the Blue Dragon eats its venomous prey they don’t completely digest them, they keep the stinging cells (nematocysts) and store them in the tips of their cerata to use as a defence tool. If you’ve heard of the power of the sting that the Man of War posses, this could be enough to send shivers down your spine every time you hear their name. The Blue dragons are able to concentrate the nematocysts and unfired cnidocytes along with the jellyfish tissue which makes the sting far more potent than the Man of War’s. 

You must be wondering how more of these bad boys get made, well they are hermaphroditic, and they cannot fertilize their own eggs so there is no time to be antisocial because they must find a mate to reproduce with. Our small, blue, friends produce eggs in long, spiral shaped egg strings that float freely in the water or stick to surfaces, but typically they lay their eggs in their prays dead carcasses. So, would you like to go swimming with these beautiful blue devils? Well guess what? If you’ve ever swam in the Atlantic or Pacific ocean you have, congratulations! 

Sources:

Heimbuch, J. (February 16, 2017). 3 fascinating facts about the blue dragons of the sea. Mother Nature Network. Retrieved November 27th, 2019 from https://www.mnn.com/earth-matters/animals/blogs/3-fascinating-facts-about-blue-dragons-sea

Hines, N. (June 19, 2018). Meet the blue dragon, the world’s most beautiful – and deadly – slug. Allthatsinteresting. Retrieved November 27th, 2019 from 

https://allthatsinteresting.com/glaucus-atlanticus 

Kelly,A. & Olson,E. (August 7, 2014). Featured creature: Blue Dragon. PBS Nature. Retrieved January 10th, 2020 from

https://www.pbs.org/wnet/nature/blog/inside-nature-featured-creature-blue-dragon/ 

Photo at top taken by : Sylke Rohrlach at March 3, 2013

Photo was taken at Bronte Beach, Sydney, NSW

https://commons.wikimedia.org/wiki/File:Blue_dragon-glaucus_atlanticus_(8599051974).jpg

Photo at bottom by : Biusch

Photo was taken at Tayrona national park, Colombia

https://commons.wikimedia.org/wiki/File:Physalia_physalis,_Tayrona_national_park,_Colombia.jpg

Common name: Mudflat Snails; Spiral Snails; Asian Hornsnail

Authors: Elliot Scott-Bigsby & Sayde Koetke

Scientific name: Batillaria cumingi

Size: Up to 3 cm (1 ¼”) in length


Identifying features: Shells are small, long, and grey-brown with 8 or 9 distinct circles.

Habitat: Found in the mid- to high intertidal zones, including but not limited to salt marshes, mud flats, pannes in estuaries, riparian zones, and wetlands.

Despite their large numbers it is sometimes surprising to find out that Batillaria cumingi is an introduced species originating from Japan and parts of Asia.  In California this species is slowly replacing the native snail Cerithidea californica: the two species currently coexist in the bays in California. They can be found in bays in British Columbia down to California.

References

Harbo, R. M (1949). Whelks to Whales: Coastal Marine Life of the Pacific Northwest. Madeira Park, BC: Harbour Publishing.

Klinkenberg, Brian. 2017. E-Fauna BC Atlas Page: Electronic Atlas of the Fauna of British Columbia. Retrieved November 9th, 2018 from http://linnet.geog.ubc.ca/efauna/Atlas/Atlas.aspx?sciname=Batillaria%20attramentaria

Dave Cowles (2009) Batillaria attramentaria (japanese false cerith,  false cerith, zoned cerith, screw shell, tall-spired snails), retrieved november 13, 2019 from:

https://inverts.wallawalla.edu/Mollusca/Gastropoda/Prosobranchia/Order_Mesogastropoda/Suborder_Taenioglossa/Family_Batillariidae/Batillaria_attramentaria.html

Purple Olive Snail

Scientific name:   Olivella biplicata

Authors: Cody C. and D. Young

Size:  2cm to 3.5cm (0.8 inch to 1.15inch)


Identifying features:

Purple Olive Snails are very attractive snails that have a smooth shell that appears highly polished.  The colour of the shell varies but is often a blend of grays and purples and pinks and many have longitudinal bands running down the length of the shell.  They often have dark lines at the edge of the whorls at the apex of the shell.

Habitat:

O. biplicata are found on sandy beaches below the high tide line from southern Alaska to northern Mexico. On Vancouver Island they are most commonly encountered by people walking along Long Beach near Tofino. They are carnivorous and plow through the sand while they are scavenging.  Though they are nocturnal they generally remain close to the surface when they burrow and some can found scavenging on the surface in the day time.  Others can be seen either by the tip of their shell or a proboscis extended above the sand.

References:

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

Lamb, A. and Hanby,B.(2005). Marine life of the Pacific Northwest: A photographic encyclopedia of invertebrates, seaweeds and selected fishes. Medeiva Park, BC: Harbour Publishing.

Pacific Geoduck

Author: Zoe Schmit

Common Name: Geoduck

Scientific Name: Panopea genersoa

Photo courtesy of Grant Dovey of the Underwater Harvesters Association and the West Coast Geoduck Research Corporation.

Identifying Features: My friend said it looks like a foot made of cream cheese while others say a skinned yam and then there are those that eat it as a tasty meal. Behold! The most phallic looking bivalve: the Geoduck (Panopea genersoa)!  The Geoduck (Panopea genersoa) is the largest bivalve in the Northern Pacific and Salish Sea areas, and the largest burrowing bivalve in the world. It has a thin shell that can reach up to 8 inches long, which always remains open, due to how large the clam is. The neck or siphons of the the clam can reach up to 1 metre in length. Its weight can also reach up 1.5 kilograms.

Habitat: P. genersoa is found in the intertidal zone of sandy beaches. The intertidal zone is where the ocean meets the land and is covered by water during high tide and is exposed land during low tide.  P. genersoa burrows itself under the sand, sometimes up to 110 metres down. The geoduck is found in Puget Sound, Washington, along the coast of British Columbia and Japan.

Food (prey): Geoducks are filter feeders. They eat mainly plankton. They siphon it in, eat it, and then eject the waste.

Predators: P. genersoa doesn’t have too many predators; the Sea Otter (Enhydra lutris), Spiny dogfish (Squalus acanthias) and people (Homo sapiens). To avoid these predators the Geoduck simply buries itself deeper in the sand. Humans harvest the Geoduck and serve them as a delicacy.

Life Cycle: P. genersoa can live to be 168 years old. To reproduce, the males spawn and the females produce 7-10 million eggs which are fertilized externally. 48 hours after being born, the shelled larvae begin swimming and eventually settle on the sandy bottom.

Recipe for Geoduck Fritters:

Ingredients

* 1 cup flour
* 1 tsp baking powder
* 1/2 teaspoon salt
* 1/8 teaspoon pepper
* 1/3 cup clam juice
* 2 eggs, beaten
* 1/3 cup milk
* 2 tsp butter, melted
* 1 geoduck clam, cleaned and diced
* Vegetable oil
* Lemon wedges

Directions

  1. Preheat oven to 200 degrees.
    2. Line a baking dish with paper towels and set aside.
    3. Sift the flour, baking powder, salt, and pepper into a mixing bowl.
    4. Add the clam juice, eggs, and milk and beat thoroughly with a wire whisk. Fold in the butter and geoduck.
    5. Fill a large saucepan or wok halfway with vegetable oil and heat to 375 degrees. Very carefully, drop large spoonfuls of batter into the hot oil and 3 to 4 minutes, turning once, or until the fritters are golden brown on both sides.
    6. Drain on paper towels, then transfer the fritters to the prepared baking sheet and place in the oven to keep warm.
    7. Garnish with lemon wedges and serve immediately.

References:

Andy, L. and Bernard, H. (2005) Marine life of the pacific northwest: A photographic encyclopedia of invertebrates, seaweeds and selected fishes. Madeira Park, BC: Harbour Publishing

Geoduck Recipes Geoduck Recipes. Retrieved January 2, 2017 from http://www.geoduckrecipes.com/

Goodwin, C.L. ; Pease, Bruce (Dec, 1989) Species Profiles, Life Histories and Environmental REquiremetns of Costal Fishes and Invertebreates (Pacific Northwest). Pacific Geoduck Clam Retrieved November 9, 2016 from http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA225230

Jerry Cahill. Geoduck “Gooey Duck” Clams. Geoduck “Gooey Duck” Clams. Retrieved November 20, 2016 from http://www.streetdirectory.com/food_editorials/cooking/chicken_recipes/geoduck_gooey_duck_clams.html

Richard E. (2000) Encyclopedia of the sea. New York City, New York: Knopf

Underwater Harvesters Association (2014). Geoduck from Canada. Geoduck from Canada | Underwater Harvesters Association. Retreived November 14, 2016 from http://www.geoduck.org/about.html


Elysia hedgpethi

Common Names: Hedgpeth’s Sea Hare, Hedgpeth’s Sapsucker

Scientific Name: Elysia hedgepethi


Photos by D. Young, Video by D. Young and Oliver S.

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

Ruby Octopus

Author: Claire Troost

Common Names: Ruby Octopus, Pacific Red Octopus, Red Octopus

Scientific Name: Octopus rubescens (Polypus rubescens)

Size Range: to 50cm (20 inch) arm spread

Identifying Features

This species was originally thought to be a juvenile  Enteroctopus dofleini, or Giant Pacific Octopus, but was later proved to be it’s own species. Knowing if what you see is a Ruby Octopus or not can be difficult, due to their ability to drastically change their appearances. This species also has three papillae below the eyes, which appear like eyelashes, a distinguishing feature against the Giant Pacific Octopus.

The mantle length of the Ruby Octopus usually reaches 8-10 cm and the arm length will reach around 30-50 cm. The weight of the adult octopus is commonly 100-400 grams.

The appearance of the this species varies widely, like most other species of octopus. It can change its shape and colour, appearing in reds, browns, whites and mixtures of the three (visit Octopus Skin Tricks for more information on octopus skin).


Amelia our Ruby Octopus about to be released back into the Pacific Ocean – a coffee pot is a great way to transfer octopus

Identifying Features

This species was originally thought to be a juvenile  Enteroctopus dofleini, or Giant Pacific Octopus, but was later proved to be it’s own species. Knowing if what you see is a Ruby Octopus or not can be difficult, due to their ability to drastically change their appearances. This species also has three papillae below the eyes, which appear like eyelashes, a distinguishing feature against the Giant Pacific Octopus.

The mantle length of the Ruby Octopus usually reaches 8-10 cm and the arm length will reach around 30-50 cm. The weight of the adult octopus is commonly 100-400 grams.

The appearance of the this species varies widely, like most other species of octopus. It can change its shape and colour, appearing in reds, browns, whites and mixtures of the three.  Follow this link for more information on skin tricks in octopus – Octopus Skin Tricks


Heading Home

Habitat

This octopus ranges from Alaska to Mexico and lives in the intertidal zone of up to 300m below the surface.It prefers kelp forests, as well as sandy and rocky areas. It lives in what is known as the benthic zone, which is the bottom of the ocean.

Diet

The octopus is a predator in the ocean, and as such has a wide range of food sources. In labs, the species has been seen eating gastropods, bivalves, crabs, barnacles and fish. In the wild, the full diet of the species is not entirely known. They seem to have a diet mainly consisting of gastropods (slugs and snails) and bivalves (clams), as well as fish.

The Ruby Octopus has excellent vision, though it mostly relies on it’s senses of smell. After the Ruby Octopus has captured a bivalve, it can open shells with it’s beak and drill holes in the shell of the prey with its radula (something similar to a tongue that some molluscs have). It then injects venom into the shell to kill the prey and can inject a chemical that separates the flesh from the shell. This is why you must be aware when picking up the Ruby Octopus, as it can bite and it’s venom may lengthen healing time.

After the Ruby Octopus kills its prey, it will keep hunting and collecting more food. It will then take the collected food back to it’s home environment and eat at it’s own pace. The shells of the prey of the Ruby Octopus are usually stacked outside of it’s residence.

It is hypothesized that the Ruby Octopus chooses its prey based on its ability to easily digest it, rather than the calorie content. This would make the Ruby Octopus a specialist predator, rather than a generalist predator.

Intelligence and Behaviour

Intelligence is defined as the skill to learn, acquire and then apply knowledge. The octopus is the smartest of the invertebrates. It has distributed intelligence, only one third of which is in its head, the rest is in its eight arms. The brains of molluscs are clusters of nerve cells throughout their body called ganglia, that serve a purpose. Octopuses have evolved to have a centralized brain. Two areas of their brain is for memory storage, as octopuses have even been known to recognize people. It’s these areas of the brain that are dedicated to learning, but are very different from a human brain.

Octopuses also have the ability to fold together every single one of its suction cups in a pincer grasp that humans use daily with our thumb and fingers. That’s over 100 pincer grasps at once.

They are very intelligent, and adept at solving problems related to their environment. When scientists gave an octopus different species of clams, some even wired shut, the octopus used different techniques to open them, based on their difficulty. It would use energy conserving techniques on less difficult prey.They have also been found to play in a boring situation. An octopus put in an empty tank with a floating bottle eventually became bored and starting siphoning water at the bottle, much like throwing a ball.

Another indication of intelligence is that individual octopuses have been found to have different personalities from each other. This was tested by putting many different octopuses in the same situations, including being given food, being threatened and having them open the tank. Some octopuses were shy and avoiding, some were active and/or passive, some were emotional, and some were combinations of the three.

Predators

The predators of an octopus will vary slightly depending on it’s size and location. These can include large fish, whales, birds and even dolphins. Most commonly, the octopus has a camouflage that allows it to go unnoticed.When discovered, an octopus will squirt ink, both causing a distraction and making it hard for the predator to see, to allow the octopus to escape. The ink also has a chemical in it that dulls the predator’s sense of smell. The octopus can also swim very fast, as it siphons water through its mantle. While escaping, it is a helpful feature that the octopus can fit into anything larger than its beak. This is because that is the only solid part of its body. If the octopus really needs to, it can also pull off one of its arms to distract the predator, and regrow it later. The severed arm however, maintains some of the octopus’s distributed intelligence, and will continue to hunt for food and attempt to bring it to a non-existent mouth.

Life Cycle

The mating season for the Ruby Octopus is usually in late August to early September. The male will use visual displays to attract the female. It will then insert the hectocotylus into the cavity of the female’s mantle where fertilization occurs. The female will put the eggs in a safe residence in early winter, where she will stay to guard them, and waft fresh water over them as they grow. The embryos will hatch in a very young stage similar to plankton, as they grow larger. Eventually they will start to live on the bottom of the ocean and become adults.

Behaviour

The behaviour of octopuses is widely varying, possibly a display of the animal’s high level of intelligence. The octopus is the most intelligent of the invertebrates, and individuals have even displayed different personalities. During hunting, the Ruby Octopus will pounce on prey and display sequences of colour changes to distract it.

References

(1953). Octopus rubescens   Berry, 1953. Retrieved from http://sealifebase.ca/summary/Octopus-rubescens.html

Borrell, B. (2009, February 27). Are Octopuses Smart? Retrieved from https://www.scientificamerican.com/article/are-octopuses-smart/

Borrell, B. (2009, February 27). Are Octopuses Smart? Retrieved from https://www.scientificamerican.com/article/are-octopuses-smart/

East Pacific Red Octopus. (2017, October 13). Retrieved from https://en.wikipedia.org/wiki/East_Pacific_red_octopus

Lamb, A., Byers, S. C., Hanby, B. P., & Hawkes, M. W. (2009). Marine life of the Pacific Northwest: A photographic encyclopedia of invertebrates, seaweeds and selected fishes. Madeira Park, BC: Harbour Publ.

Meschkat, C., Fretwell, K., Starzomski, B., & Biodiversity of the Central Coast. (2014). Pacific red octopus • Octopus rubescens. Retrieved from http://www.centralcoastbiodiversity.org/pacific-red-octopus-bull-octopus-rubescens.html

Ocean Networks Canada. (2010, June 21). Ocean Networks Canada. Retrieved from https://www.oceannetworks.ca/east-pacific-red-octopus

Octopus Worlds. (n.d.). East Pacific Red Octopus. Retrieved from http://www.octopusworlds.com/east-pacific-red-octopus/

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.


Identification
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.
  
Distribution
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.
  
Food
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.
  
Predators
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.
  
Reproduction
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.
  
References
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 http://www.seaslugforum.net/find/20125  
  
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