Join me in the cold, dark, life-sustaining NE Pacific Ocean to discover the great beauty, mystery and fragility hidden there.

Posts from the ‘MARINE INVERTEBRATES’ category

Abseiling Sea Snail

Go ahead, say that 5 times “abseiling sea snail, abseiling sea snail, abseiling sea snail . . .”

Now that you’ve warmed up and possibly developed a lisp, here are some details about a marine snail species that can climb, has an incredible sense of smell, and can deter much bigger predators.

Meet the Wrinkled Amphissia. No, I do not make up these names.

Amphissa columbiana can be up to 3 cm long, and is also known as the “Wrinkled Dove Snail”. 

 

Climbing

In this species, a gland near the foot secretes thick mucus that allows them to climb up and down and suspend themselves in the sea.

See the two photos below. I know it is so difficult to see the mucus strand.

Scavenging

Where are they abseiling to?

These marine snails are big time scavengers and are very active, using their long siphon to smell out the dead (photo below shows the siphon well).

It appears they can detect the chemicals of decay incredibly well in the water. Often a pile of them are scavenging together.

Wrinkled Amphissa amid Fringed Filament-Worms. If you look really closely you can even see some of the snail’s eggs attached the shell of the snail in the foreground. ©Jackie Hildering.

 

From Braidwaithe et al 2017 regarding feeding. “They appear to locate food resources primarily through chemosensory cues, often following conspecific mucus trails and sometimes congregating around actively feeding sea stars. The chemical cues that draw A. columbiana to food act as feeding stimulants; the addition of scent from a damaged animal induced the snails to feed on healthy prey. The ability to sense chemical cues from damaged animals, including those being consumed by feeding sea stars, creates scavenging opportunities other gastropods may be unable to exploit.”

 

Wrinkled Amphissa aggregation scavenging on a dead Rat Fish. The much larger snails feeding here are Oregon Tritons (Fusitron oregonensis to 13 cm long).The Tritons might follow the scent trails of the Amphissas to the food!

 

Photo above and below. Wrinkled Amphissas and Oregon Tritons snacking on a dead Lingcod. Nothing is wasted in the wild. ©Jackie Hildering.

Biting

They also have a wicked defense against sea stars where they insert their mouth parts (proboscis) into one of the grooves on the underside of the arms of predatory sea stars, biting a nerve.

From Braidwaithe et al  2010″The injury, which generally repelled the attacking sea star, immobilized the affected arm, rendering it useless for several days. The biting defense appears to be effective against several sea star species and may reduce predation on A. columbiana.” Some crab species do feed on them. 

Such remarkable adaptations in a sea of remarkable organisms which means I will be writing blogs and allotting abundant alliteration for a long, long time to come.


Adapting over thousands of years

I am sharing the photo below to give a sense of the diversity in the mollusc phylum to which snails belong.

“Mollis” means soft in Latin and the molluscs are our soft-bodied terrestrial and marine invertebrate neighbours. Their phylum is the second largest (the insects take first place). Note that all the organisms in this photo start off as larvae in the planktonic soup of the Ocean.

You can imagine how excited I was to chance upon  5 highly diverse marine mollusc species in one small area.

 

Details about the species in the photo:

– To the left of the Wrinkled Amphissa is a Keyhole Limpet who makes its own hat-like shell and grazes on rocks (preferred diet is bryozoans). Limpet species need to suction down hard on a flat surface because they do not have a shell to cover its underside. The individual here is in a risky position as a predator could easily flip and consume limpet. Too cool not to share with you is that engineers have found that the “teeth”  of limpets (the radula) are made of the strongest biological material ever tested (and the teeth are less than a millimetre long)! Note that marine snails like the Wrinkled Amphissa are protected not only by a shell, but they have an operculum which serves like a door to close the entrance to the shell when the snails withdrawn into its shell.

– Below the Wrinkled Amphissa, a Blue-Lined Chiton. Chitons make 8 plates to protect themselves. They are grazers like limpets. They too need to be able to suction down to protect themselves but do not need to be on a flat surface since the plates allow them to “contour” onto the surface.

– To the right of the Wrinkled Amphissa is a species of sea slug known as the Pomegranate Aeolid. It has “naked gills” and is therefore in the group of sea slugs known as “nudibranchs”. Sea slugs are marine mollusc without ANY shell or plates for protection. They are protected by feeding on animals with stinging cells (nematocysts) which become incorporated into those structures on its back (they are called cerata and also function as the naked gills for respiration). Specifically, Pomegranate Aeolids feed on Raspberry Hydroids which were only acknowledged as a new species in 2013. Scientific name is “Zyzzyzus rubusidaeus” and again, I do NOT make up these names. 🙂 See photo below.

– Below the chiton, if you look very carefully, is a very tiny sea slug species. I believe this is a Sea Cherub – a type of sea slug that swims and does not have naked gills (and therefore is not a nudibranch).

Not in the photo but to be considered too in the incredible diversity among marine molluscs is – octopuses!

Pomegranate Aeolid feeding on Raspberry Hydroids. ©Jackie Hildering.


Sources:

Anita Brinckmann-Voss & Dale R. Calder (2013). Zyzzyzus rubusidaeus (Cnidaria, Hydrozoa, Tubulariidae), a new species of anthoathecate hydroid from the coast of British Columbia, Canada” (PDF). Zootaxa. 3666 (3): 389–397.

Lee F. Braithwaite, Anthony Rodríguez-Vargas, Miles Borgen, Brian L. Bingham  (2017).”Feeding Behavior of the Wrinkled Dove Snail Amphissa columbiana,” Northwest Science, 91(4), 356-366.

Lee F. Braithwaite, Bruce Stone, Brian L. Bingham (2010). “Defensive Behaviors of the Gastropod Amphissa columbiana,” Journal of Shellfish Research, 29(1), 217-222.

Phenomenal Feather Stars

Phenomenal?  Yeah they are.

The lineage of “feather stars” (members of the crinoid class) goes back 485 million years, give or take a million. They crawl around. They swim in the most extraordinary way. You’ll see. 🙂

Another non-scientific name used for feather stars is “sea lilies” but I avoid that. As pretty as the name is, I believe it adds to confusion. These are animals, not plants. They are echinoderms, relatives to sea stars, brittle stars, sea urchins and sea cucumbers. Also “sea lily” is a name more often used for the crinoid relatives that have a stalk into adulthood. Only juvenile feather stars have a stalk. Then, get this . . .  they detach and crawl down their own stalk to perch directly on the bottom! (Source: A Snail’s Odyssey). See below.

 

 

There are many feather star species in the world but the detail here is about the species commonly found in shallow water off the coast of British Columbia – Florometra serratissima (range is from the Aleutian Islands to Baja California).

Feather stars have 5 feathery arms that split to form 10 or more arm branches that are used to gather bits of organic matter (snacks) out of the water. With arm’s outreached, Florometra serratissima is up to 25 cm wide and they are up to 31 cm tall. Feather stars also use their arms to swim as recently captured in this video by dive buddy, Brenda Irving. They swim as if “walking up an invisible staircase” (quote from Lamb and Handby).

Phenomenal – right?

The following detail on their locomotion is largely compiled from the brilliant resourceA Snail’s Odyssey by Tom Carefoot, Professor Emeritus, Department of Zoology, University of British Columbia.



How do they swim? 

“Florometra serratissima is the only swimming species of crinoid on the west coast of North America. It swims by graceful undulation of its arms in 3 sets, each set moving successively but overlapping. Thus, while about one-third of the arms are in power stroke, another third are in recovery, and the last third somewhere in between. During the power stroke the arms extend out maximally for greatest frictional resistance, while during the recovery stroke they bend inwards to minimise resistance.”

“The sets comprise two triplets and one quadruplet, are their composition with respect to specific arms is invariable (see sequence below). In the scenario shown, swimming is initiated by the blue triplet making a downstroke, followed 1sec later by the green quadruplet, and 2 seconds later by the orange triplet. An entire sequence is completed, then, in about 3 seconds, and the pattern may be repeated for up to 30 seconds.” (Source: A Snail’s Odyssey).

After several strokes to move vertically (to a mean height of 29 cm at an average speed of 5.4 cm/sec), individuals often turn 90 degrees and swim horizontally. If there is current, they will swim with the current. Horizontal swimming is achieved by the 5 arms furthest away from the bottom making stronger downward pulses than the arms closest to the bottom. (Source: Shaw and Fontaine. See Figure 3 at this link if you wish to better understand the horizontal movement).

Swim speed was found to occur in “short, repeatable bursts of 10 to 30 seconds. Continuous swimming beyond 4 minutes provokes a refractory period lasting 5 to 17 minutes during which individuals are incapable of swimming.” (Source: Shaw and Fontaine).

Feather stars end up back on the ocean bottom by stopping movement, and then “parachuting” down (as can be seen at the end of the video above).

Swimming and crawling can be stimulated by current and touch from predators such as Sunflower Stars (Pycnopodia helianthoides) and crabs. Research supports that if touched by a Sunflower Star, there is about a 5 second delay followed by “several power strokes carrying the stimulated individual 1 to 3 metres away.  This cycle can be repeated several times and capture by a sea star is actually thought to be rare.” (Source: A Snail’s Odyssey).

Particles of food are captured by the pinnules, moved by tube feet and cilia and form a bolus, which is moved down a “food grove” toward the mouth. This delicate looking animal has to be strong enough to be in high current areas as that’s where the feeding is good. The cirri hold on to surfaces and allow the Feather Star to crawl. ©2019 Jackie Hildering.


Yes, they also crawl! 

Crawling has been found to be feather stars’ main means of getting around with swimming being only in response to a predator or touch.

“Stalkless crinoids such as Florometra serratissima anchor to the substratum [ocean bottom] using flexible cirri [these have been described as holding on like bird’s feet do]. The cirri are jointed and can slowly bend and straighten. . . . ” (Source: A Snail’s Odyssey).

The arms are also involved in crawling around. The 10 arms attach to the bottom with small hooks, the central part of the feather star’s body (the calyx and cirri) is lifted. “The arms then contract and extend on opposite sides of the body, which moves it in one direction or the other. Repetition of this behaviour will gradually move the individual to a new location.” (Source: A Snail’s Odyssey)


What a remarkable species with relatives dating back 485 million years and defences including: (1) being able to regenerate arms; (2) having a body that has little nutritional content, is hard, and may taste bad AND; (3) is strong enough to withstand the current that delivers snacks, but light enough to allow swimming as an escape response.

 

Above: Feather star near Telegraph Cove at about 10 m depth. Species reported to be from 10 to 1252 m. Believe this to be a female! From A Snail’s Odyssey: “Studies on feather stars Florometra serratissima at Bamfield Marine Sciences Centre, British Columbia mostly have separate sexes, but a small percentage is hermaphroditic. Breeding is continuous throughout most of the year and “dribble” spawning is the norm. Gonads appear as swellings on special pinnules of the arms, known as genital pinnules. Genital pinnules occur on all 10 arms, but concentrate in the lower third of each arm. Male individuals can be recognised by the creamy white colour of their genital pinnules, and females by pink or orange-coloured pinnules.” More detail on reproduction of feather stars at this link. Photo ©2019 Jackie Hildering.

Above: This remarkable photo by Neil McDaniel shows an individual with eggs (orange) and allows you to see the incredible fine details of the “feathers” – the pinnules of Florometra serratissima. 

Above: Another fantastic capture by Neil McDaniel.  Florometra serratissima climbing down his/her stalk to live an an adult, moving around on its cirri and swimming.

Round Lipped Boot Sponge (1 m tall) near Powell River, festooned with feather stars (Florometra serratissima). Also, see the juvenile Giant Sea Cucumbers?

 

Feather stars at the same site as the individual in the video – the Knight Inlet Sill. Animals to the right are brachipods. ©2019 Jackie Hildering.

 

Above: Dive buddy, Brenda Irving, just before taking the video above. Here with the coral Primnoa pacifica which is usually found at great depth but the upwellings at this site in Knight Inlet lead to it occurring much shallower too, up to ~15 m. The animals on the coral in this image are Orange Hermit Crabs. Detail on this species of coral and this extraordinary site can be read at “A Proposal to Create a Marine Refuge at the Knight Inlet Sill, British Columbia to Protect Unique Gorgonian Coral Habitat” by Neil McDaniel. Click here.


Sources:

Markus . . . and the Octopus.

Today something extraordinary happened.

It happened when we placed a memorial for a dear departed friend, Markus Kronwitter.

My primary reason for sharing this is for Markus’ family and friends but, I think others will find something here too.

You see, a Giant Pacific Octopus attended and sat right atop the memorial.

Let me recount using photos.

Memorial made by Stephanie Lacasse.

 

Markus owned and operated North Island Diving in Port Hardy. He was a dear friend and incredibly important to our dive club, the Top Island Econauts. He died more than 3 years ago and the memorial today was to honour him and maybe offer some comfort to his wife Cecelia and his two daughters, Rosie and Jennifer.

The location was Five Fathom Rock just outside Port Hardy.  Part of Markus’ legacy is that he fought for this rocky reef to be recognized as a Rockfish Conservation Area. (More about the significance of that in my eulogy at the end of this blog).

After we shared thoughts about Markus at the surface, down we went to the highest point of the reef. We would wait there till the memorial was carefully descended by Steve Lacasse of Sun Fun Divers using a lift bag and rope.

We wanted to position the memorial there, near a sunken metal beer keg. The keg used to be a mooring float on this site. It was put there by Markus but, by mysterious means, had sunk to the bottom.

As soon as we got to where the memorial was to be placed, I saw a Giant Pacific Octopus, fully out in the open.

You can even see the beer keg right in the background.

After about 5 minutes, he retreated partially into his den, likely because of some annoying underwater photographer with flashing lights.

Note that I do know this was a male Giant Pacific Octopus because the third arm on the right was a “hectocotylus arm”. Only males have the hectocotylus which stores sperm. More on that at this link. (This individual also had an injured arm. It was only about half length but will regrow. Yes, some of the awe that is octopuses, is that they can regenerate limbs.)

Giant Pacific Octopus in his den.

But then . . . when Steve arrived with the memorial, the Giant Pacific Octopus darted out of his den, landed right atop the memorial and started flashing white. See the memorial under the octopus in the photos below?

Steve Lacasse with the octopus on the memorial which was still attached to the rope and lift bag.

 

You can imagine how we marvelled as this unfolded and that some pretty big emotions were felt.

Eventually, the Giant Pacific Octopus moved away. Then, the memorial could be positioned as we had intended, but not before a mature male Wolf Eel also went swimming by.

There’s no photo of that I am afraid. I was a little overwhelmed.

Memorial positioned.

 

Dive club members from left to right: Dwayne Rudy, Steve Lacasse, Natasha Dickinson, Gord Jenkins and Andy Hanke.

Somewhat dizzied by emotion, we continued with the dive.

Below, I include some photos of what we saw, especially to give Markus’ loved ones a sense of what this site is like.

Mature male Wolf-Eel in his den, very near the memorial.

 

One of 100s of Black Rockfish at this site (and a Mottled Star).

 

Male Lingcod guarding an egg mass with 100s of eggs.

 

Male Ling Cod. The boulders here give an indication of why this is such ideal fish habitat. There are so many crevices to hide in and rocks to lounge upon.

 

Rose Anemones aka Fish-Eating Telias. Sun shining down from the surface, five fathoms above us.

 

Tiger Rockfish – longevity can be 116 years WHEN given a chance.

 

See the male Lingcod under the huge mass of eggs? He’s got a lot to protect!

 

And then . . . just as we were about to ascend, there he was again – the same Giant Pacific Octopus.

The Giant Pacific Octopus with dive buddy, Natasha Dickinson.

 

How I wish we could have stayed longer. We had to surface to a far less mysterious world, but with hearts full and so much to tell Cecelia, Jenny and Rosie.

Goodbye Markus.

We’ll be visiting again soon.


My Eulogy for Markus. 

It’s my great honour to say a few words before we dive on Five Fathom Rock to position Markus’ memorial.

I of course found it excruciating to try to find the words fitting of Markus, because you have to tap into the emotion to find the words.

It’s been more than 3 years since Markus died. Cecelia, Jenny and Rosie you need the words and, even more, you need this place where your thoughts and feelings can be anchored.

In trying to find the words, I dared remember what it felt like to be around Markus. I don’t think that I know anyone else who was quite like him in knowing the right thing to do, no matter how hard it would be and no matter how many injustices he had suffered.

Markus was about making things better and standing up for what was right. He was a man of truth and science. He appeared unflinching in facing reality. He did not suffer fools. He saw through people with crystalline clarity. He walked his own path – in red “holely soles” and multi-coloured pants – and had the wisdom to stop to have Cecelia join to walk beside him.

He made hard decisions.

He . . . was . . . a . . . fighter.

He fought to be here on northern Vancouver Island.

He fought for his girls.

He fought for our dive club.

He fought for the fishes, now flourishing beneath us.

He fought for his life.
[When diagnosed with cancer, he was told he had 2 years to live. He lived for 14 years post diagnosis].

And he has left an extraordinary legacy.

Part of this, is the legacy of Five Fathom Rock.

Markus fought for this to be a Rockfish Conservation Area so that the fish that live here might get a chance to grow bigger, reproduce more, and to thrive.

And there’s success. It’s so beautiful down there Rosie, Jenny and Cecelia. The fishes are thriving – there are clouds of rockfish and it’s so powerful to think that some, like the Tiger Rockfish, might get a chance to live to be more than 100-years-old.

If there were any place where I could picture Markus, it would be here darting around with yellow fins, fish-like himself. Clearly so at home . . . here.

His efforts for Five Fathom included trying to have a mooring here and his creativity was to use a big metal beer keg. It’s down there now, on the highest part of the reef , close to where there are 2 Wolf-Eels. It’s where we’ll attach the memorial.

And how perfect that this will happen at a time when the Lingcod fathers are protecting the next generation, standing guard, not suffering fools, making very clear when you’re trying to get too close without good intent. Fiercely fighting for the next generation, with an extraordinary sense of place.

He loved it here.

It’s impossible to forget him here.

Not that there is any possibility of forgetting Markus or what he stood for.

His legacy of course includes you Rosie, Jenny and Cecelia. He loved you so much and I can’t even imagine how hard he fought wanting to be here still to protect you, to make sure you would always be okay.

Jennifer and Rosie, you are fighters like your Papa Markus.

Jenny – I also think you have his sense of purpose.

Rosie  – I think you have his sense of place.

Cecelia – the love in your eyes makes clear how you carry Markus with you always.

Markus Kronwitter.
It is here on Northern Vancouver Island that he found his wild.
It is with you three, that he found love.

 

 

 

 

 

 

 

 


Compilation of photos and video below.

 

How Do Octopuses Poo?

It’s one of the characteristics that unifies every living thing on the planet – we all need to get rid of waste.

How do octopuses do it? See the video and explanation below.

Why share? Because I solidly believe the world can be a better place through understanding and respecting the commonalities and differences of others AND through marvelling at the natural world.

With great thanks to Krystal Janecki for her video and Neil McDaniel and Jim Cosgrove for their knowledge.

Video above: Giant Pacific Octopus defecating by ©Krystal Janicki November 5 2018, Madrona in Nanoose Bay, British Columbia, Canada. Observations are that in areas where octopuses appear to be eating more bivalves like Swimming Scallops, the poo is whiter / paler in colour. In areas where they appear to be eating more Red Rock Crabs, the poo is various shades of red. (Source: Jim Cosgrove, personal communication).   


The detail below on octopus digestion is from “Super Suckers – The Giant Pacific Octopus and Other Cephalopods of the Pacific Coast
by James A. Cosgrove & Neil McDaniel (Harbour Publishing):

“The first structure for food gathering [in octopuses] is the interbrachial web, the umbrella-like membrane between the arms that the octopus used to enfold food such as crabs, shrimps and sometimes even fishes and birds.The web forms a bag-like container that holds prey close the the mouth . . .

Giant Pacific Octopus hunting. Notice the webbing between the arms = the interbrachial web. 
©Jackie Hildering.

The second structure is the mouth. An octopus has two pair of salivary glads, anterior (front) and posterior (rear). The posterior salivary glans produce a toxin called cephalotoxin. in giant Pacific octopuses this is not known to be deadly to humans, whereas in the blue-ringed octopus of the South Pacific it has killed people. When an octopus captures food in its web, it secretes cephalotoxin into the water, where it is absorbed through the gills of its prey. The neurotoxin affects the nervous system and causes the prey to lose consciousness and stop struggling. The octopus can then use its suckers to aid in dismembering prey such as crab.

The beak, the hardest part of the octopus, is made of the same chitonous material as human fingernails. It is black and looks like the beak of a parrot. The mouth also has a specialized tongue called a radula. The file-like organ is covered with tiny, sharp teeth that are replaced when they wear down, much as sharks regrow teeth. The radular teeth shred the prey’s tissue once the beak has bitten the food into chunks. Working together with the beak and radula are secretions of the anterior (front) salivary gland. The gland produces a mixture of substances called enzymes, which cause the food to break down quickly inot a jelly-like substance that can be easily digested. A combination of the enzymes and the radula enables an octopus to winkle even the tiniest bit of tissue out of the tip of a crab’s leg.

Giant Pacific Octopus beak. It’s made of keratin.

Once the food is captured, eaten and swallowed, it travels along a short tube called the esophagus (similar to the throat in a human) to a structure called the crop. This is not exactly the same as a bird’s crop, but it does function as a storage place for undigested food.

If the stomach is empty, food passed immediately from the crop to the stomach, which despite distinct differences, functions much like our stomach. In the giant Pacific octopus the digestive enzymes do not come from the wall of the stomach but are produced by the live and introduced into the stomach through ducts. These enzymes cause the food to break down into small molecules that the blood absorbs and transports back to the liver. There they are processed and distributed to the cells of the body. This dual-function liver is different from a human’s whose liver primarily deals with the products of digested food.

Summary of octopus digestion. Source: Super Suckers by James Cosgrove and Neil McDaniel
Harbour Publishing. Illustration by Adrienne Atkins.

Now we find another major difference from vertebrates such as humans and also from squids. Once the food in the octopus stomach is digested, the waste material has to be evacuated. The octopus stomach, however, has only a single tube leading in and out. This means that the waste material must be evacuated through the same tube the food entered before more food can be introduced for digestion. You might call this the “digestion on the instalment plan.” The waste comes out of the stomach into the intestine, which encapsulates it and moves it along till it eventually reaches the end of the intestine located at the entrance to the funnel [aka siphon]. Octopus poop, ejected from the funnel, looks a bit like a slender . . . ribbon . . . .

In giant Pacific octopuses the processing of food, depending on what is being eaten, can take many hours. On average these octopuses make six hunting trips a day, reposing in their den most of the time while they process food.”


Below, video of a giant Pacific octopus hunting. In this encounter, the octopus passes directly over a mature male Wolf Eel in his den. THEN, a Decorator Warbonnet emerges as well.


 

Diagram below names addition octopus anatomy.

Further octopus anatomy. Source: Super Suckers by James Cosgrove and Neil McDaniel
Harbour Publishing. Illustration by Adrienne Atkins.

Lessons Learned from Octopuses

It’s Canadian Thanksgiving and World Octopus Day (OCTOber 8th = get it?).

There’s so much to be grateful for. The health and freedom that allows me to live this life of depth; the love and support of buddies, family and community; AND the lessons learned, ESPECIALLY from octopuses.

What essential life lessons learned from them?

  1. Do not fear what may look foreign;
  2. Respect alternative intelligences;
  3. If necessary, blend in to escape detection;
  4. When you know what you want, hold on tight;
  5. Trust in your ability to squeeze through tight spaces and come out okay on the other side;
  6. Ink out the negative in your life and jet away, leaving it behind you;
  7. Know your home and keep the garbage outside; and
  8. Be big-hearted (octopuses have three), guard the next generation, and use your beak when needed!

And what’s going on in this photo? All is told about my buddy, this female Giant Pacific Octopus, and the Copper Rockfish (see him/her?) in my blog “Gentle Giants. What to do when you find your dive buddy with a Giant Pacific Octopus on her head“.

And thankful for YOU that you care enough to read this blog and help make my efforts feel so worthwhile. I’ll stay at it till I am an octogenarian (and beyond).

Opalescent Nudibranch – 3 Distinct “Hermissenda” Species in the North Pacific Ocean.

As a result of making the following post on social media, I learned that there has been a change in classifying the “Opalescent Nudibranch”.

It was Robin Agarwal who educated me and shared the following incredible photo from Monterey, California.

As you can see, the species on the left is more similar to the one I posted and which we call the “Opalescent Nudibranch” in British Columbia.

However, it has been determined (2016) that there are 3 species in the “Hermissenda” genus (all are up to about 9 cm long). One is found in the Northwest Pacific Ocean from Japan to the Russian Far East so there is no worry about confusing that one on our coast.  But, for the other two species, their range overlaps in Northern California where Robin took the photo.

 

This has of course led to the need for two common names to differentiate them there. The species on the right is being referenced as the “Opalescent Nudibranch” (reinstating the species name Hermissenda opalescens). The one on the left has retained the name Hermissenda crassicornis and is being referenced as the “Thick-Horned Nudibranch” where the species ranges overlap.

However, off British Columbia’s coast we are only likely to see the species on the left with its range being from Alaska to Northern California. Thereby, I anticipate this beautiful species will keep on being referenced as the “Opalescent Nudibranch” in the vernacular.

What are the differences between these two species?  I am so glad you asked as I totally nerded out and made a summary table to differentiate the 3 species reported in the research “The Model Organism Hermissenda crassicornis (Gastropoda: Heterobranchia) Is a Species Complex“.

The table is just for you my fellow nudibranch nerds.

But, I’ll cut to the conclusion. Don’t be fooled by the colour of the two species found in the Northeast Pacific Ocean. The colour of the cerata in BOTH species can vary from light brown to dark brown to bright orange. Cerata are the structures on some sea slugs species’ backs that have both a respiratory and defence function. The tips contain the stinging cells (nematocysts) of the nudibranch’s prey e.g. hydroids.

The easy way to differentiate the two Hermissenda species in the Northeast Pacific Ocean, is to look for white lines on the cerata. The species most often found off the BC Coast has white lines. The other does not. See my photo below to note this easily identifiable feature (and, if you need some amusement, have a look for the little hermit crab).

 

And now, for that summary table I promised you.

Then, more photos of the beautiful Hermissenda species found off our coast – Hermissenda crassicornis.

I share these to show the variation of colour in the species  but also, because by any name and classification, there can never be enough photos of such a stunning ambassador for the colour and biodiversity found in these cold, dark seas.

Source of table information and photos: Lindsay, T., & Valdés, Á. (2016). The Model Organism Hermissenda crassicornis (Gastropoda: Heterobranchia) Is a Species Complex. PLoS ONE, 11(4), e0154265. http://doi.org/10.1371/journal.pone.0154265. Click to enlarge.

 

See my previous blog at the link for “Attack of the Sea Slugs” in which one Opalescent Nudibranch attacks another.

 

Feeding on Orange Hydroids. ©Jackie Hildering.

Hermissensa crassicornis feeding on Bushy Pink-Mouth Hydroids. Red-Gilled Nudibranch also snacking away in the background.©Jackie Hildering.

Hermissensa crassicornis on Eel Grass. ©Jackie Hildering.

With a “Jointed Three-Section Tubeworm”. ©Jackie Hildering.

Feeding on hydroids, Red Soft Corals to the left and crawling on a Red Ascidian (highly advanced invertebrate, the most advanced of all in the image). ©Jackie Hildering.

Hermissensa crassicornis feeding on Pink-Mouth Hydroids. Here you can very clearly see the distinctive white lines on the cerata. ©Jackie Hildering.

Hermissensa crassicornis on Bull Kelp. Hooded Nudibranchs in the background. ©Jackie Hildering.

On Red Soft Coral. ©Jackie Hildering.

Hermissensa crassicornis on Solitary Pink-Mouth Hydroid. ©Jackie Hildering

Hermissensa crassicornis egg mass. ©Jackie Hildering

Who Goes There? Dizzying tracks in the sand.

Let me take you on a little mystery that filled me with big wonder, inspiration and happiness.

It goes back to July of 2017 when I was naturalist around Haida Gwaii with Maple Leaf Adventures.

Let’s make it a photo essay.

To set the stage, here’s the boat and the crew.

Crew from left to right: Mate -Lynsey Rebbetoy, Deckhand -Terese Ayre, Naturalist -You-Know-Who, Captain- Ashley Stokes, Chef -Yasmin Ashi.

You’ll note that the beautiful, historic sailing ship was operated by an all female crew on this trip. Important to note? Yes, but let me not digress.

Here’s the beach at Woodruff Bay near Cape St. James.

The discovery was made by the child I was so glad was on the trip.

Meet Kay from Germany.

Like any smart, curious and observant young person would, she asked what had made the crazy, convoluted patterns in the sand.

Here’s a closer look . . .

. . . and an even closer look.

I didn’t know what species had made those remarkable, dizzying tracks. But, the best things had come together – a mystery, a child, and the chance to discover the answer together.

We struck out to solve the mystery and found lots of little clam shells near the tracks.


We looked more closely at the tracks.

And found the tiny clams IN the tracks.

And then we noted what they were doing. They were licking the sand!

We had found the animal that was making the tracks and concluded the tiny clams must be feeding on organic material in this way. It is known as “deposit feeding” whereby the bivalves use their inhalant siphons to sweep the sand for detritus and microbes = snacks.

We were in awe at thinking of how much sand they must process to leave such long individual tracks and that they must be doing this quite quickly.

Upon returning to the ship, I was able to use the resources there to determine that the tiny clam was some species a “Tellin”.

However, it took my emailing my mollusc expert friends to have the species of Tellin confirmed.

Naturalist supreme, Bill Merilees, let me know I had “met British Columbia’s most beautiful clam Tellina nuculoides, the Salmon Tellin.” He also shared the results of his work to study their growth rings (imagine the dedication needed to count the growth rings of a large sample of tiny clams.) Bill’s research suggests Salmon Tellins can live to age 11 or 12.

Armed with their species name, I was able to find out a bit more.Their maximum size is 2 cm and their range is from southern Alaska to northern California. I presume the “salmon” in their common name refers to their beautiful colour.

I became even more awe-inspired to learn that research supports that bivalves like Tellins select particles based on physical and/or chemical properties that are poorly understood! (Source: https://doi.org/10.1016/j.jembe.2004.03.002.)

Imagine THAT while you watch my blurry video of the Salmon Tellins licking the sand.

To conclude, I will resist all the puns I could be using to be “tellin” it like it is. (Oops, clearly I am not entirely successful in resisting.)

Rather, I will share the quote with which mollusc expert Rick Harbo responded when I asked him about the species and their tracks.

He reflected on the tracks made by mollusc species who feed in this way with the words of Gandalf from Lord of the Rings  . . .

“All who wander are not lost”.

 

The happiness that comes with connection to nature and making discoveries – Kay with a boa of “Feather Boa Kelp” that had washed onto the beach. Be on the lookout for Salmon Tellins on a fine sand beach from Alaska to California. Note that other mollusc species (and worms, some sea slugs, etc) also leave tracks in the sand. More on other trail-blazing species in the future. 

Shelled Sea Slug! A small mystery solved.

Here’s a bit of a mystery that took me more than a year to sort out.

On April 27th, 2016, I found this egg mass while diving in Browning Pass with God’s Pocket Resort. This is to the north of where I live and is somewhere I only have the joy of diving a couple of times a year.

Mystery sea slug egg mass among horseshoe worms. (From Neil McDaniel re. worm ID – “they are Phoronids most likely Phoronopsis harmeri” – April 2016. ©Jackie Hildering.

I recognized it was likely a sea slug egg mass but did not know the species.

More than a year passed. On May 7th, 2017, I had a chance to dive the same site again and so hoped to find the species who laid the eggs. We quickly swam to where I had found the egg mass the year prior, into the shallows (~5m), and hovered over the ocean bottom strewn with bits of shell remains.

And I found these . . .

Tiny snail-like animals, plowing through the bits of shell and urchin remains. One, two, three . . . six of them!

I tried to calm myself down, to get photos, and to watch how, despite their soft bodies and the sharp bits of shell, they were able to even push under the surface.

They were Stripe Barrel Shells (Rictaxis punctocaelatus with shells only to 2 cm long)!

A “Striped Barrel Shell” beside an urchin spine, giving a sense of how small these animals area. ©2017 Jackie Hildering.

These are often mistaken as being a marine snail (prosobranch) like a whelk but they are a type of “bubble shell” sea slug. They are also not nudibranchs. They have a thin shell and do not have “naked gills”. Therefore they do not belong in the “nudibranch” sub-group of sea slugs (opisthobranchs).  For the classification super nerds, see this link or the graphic at the end of this blog for my attempt at offering clarity.

Plowing down into the shell debris! ©2017 Jackie Hildering.

Please know that I am not suggesting that this is a rare species. Rather, they are hard to find. Their size makes them hard to see; divers often do not target the sand or shell-covered bottoms where they live; AND . . . . they are often just under the surface.

I was incredibly fortunate therefore to find them out and about – maybe feeding on algae and/or trying to smell where a mate might be (and we think WE’RE challenged in finding a partner!)

And how about those eggs? Are they a match?

Yes, they are! I was able to confirm this thanks to the knowledge and brilliant documentation of Jeff Goddard on the Sea Slug Forum (see below).

Source: Sea Slug Forum; Jeff Goddard. 

 

Another little mystery solved.

Another big influx of wonder about the life in the NE Pacific Ocean! 🙂

 

Attempt at sea slug classification ©Jackie Hildering.

Giant Siphonophore (Prayja species)

Here’s another fabulously unique jelly-like drifter for you. It’s a “Giant Siphonophore” which can be up to 50 metres long. That’s right – 50 metres – albeit the sightings near the surface are usually much smaller like these two I saw north of Port Hardy (around 2 to 3 meters).

They are not usually common off the coast of British Columbia but, like the recent sightings of many pyrosomes, their presence indicates that there must be warmer waters. They are regulars off the coast of central California.

Paired swimming bells and long stem of a Giant Siphonophore (aka Bell-Headed Tailed Jelly) ©2017 Jackie Hildering.

Siphonophore jellies are so remarkable. While they appear to be a single animal, they are a colony of individuals (“zooids”) with very specialized jobs. The paired bells aid the propulsion of the colony (pneumatophores).  The units of the long stem are known as “cormidia”. Can you discern the individual units in the image below? Each of these segments has parts for reproduction (gonozooids), cacthing prey and digestion (gastrozooids), and defence (dactylozooids)by having stinging cells (nematocysts). While this species does deliver a bit of a sting, it packs no where near the punch of the most well-known siphonophore – the Portuguese Man o’ War.

Tail segment of a Giant Siphonophore with dive buddy and his video light in the background. This one did not have the swimming bells. The bright yellow colour of the “zooids” in the stem is distinct in this species of siphonophore. ©2017 Jackie Hildering.

What had me quite confused when I first saw the species, is that Giant Siphonophores often do not have the swimming bells – just the stem of individuals. These apparently have a role in reproduction (and are known as eudoxids) but cannot regenerate the whole colony. (Added bonus to this blog – more words for the next time you play Scrabble!)

Another perspective on the paired swimming bells (pneumatophores). ©2017 Jackie Hildering.

In what little information I could find on this species, there was this fabulously, dramatic descriptor: “The giant gelatinous predator moves silently through cold, dark waters, propelled by a pair of expanding and contracting swimming bells. Its rope-like body is actually a colony of almost a thousand individual subsections, each performing a specific task. Some provide propulsion, others, reproductive functions; but most specialize in capturing and devouring prey. When hunting, these sections deploy thousands of slender, stinging tentacles to capture drifting krill, copepods, small fish, and other jellies. Almost anything blundering into this deadly net of tentacles soon finds itself stuffed into the nearest waiting mouth.” (Source: The Ecology Center).

And just in case this all is not fascinating enough, the species is also bioluminescent. It produces a bright blue light when disturbed, briefly illuminating our dark, mysterious, life-sustaining sea.

Smaller Bell-Headed Tailed Jelly; April 2nd, 2018; Browning Pass, British Columbia.

Sources:

Decorator Crabs! The best-dressed in the NE Pacific Ocean.

Are you ready? I’ve been collecting these photos for a long time. Now, finally, I think I have enough to deliver this marine fashion show to you – the best dressed of the NE Pacific Ocean!

Decorator crabs are camo-crabs. They pluck bits of life from their surroundings and attach it to themselves. AND, if their surroundings change, they change their outfit.

Graceful Decorator Crab covered with hydroids including the “Raspberry Hydroid” which was only recognized as a new species in 2013 with the area near Telegraph Cove (Weynton Pass) being one of the few areas these colonies are known to live. ©Jackie Hildering.

This is highly functional fashion. Not only does this covering of life allow the crabs to hide from potential predators, it also apparently changes the way the crabs feel and taste in a way that deters their predators. Sponges taste bad or are even toxic to many predators and animals like hydroids and other “cnidarians” have stinging cells. Thereby, if you cover yourself with sponges or cnidarians, predators be gone!

Graceful Decorator Crab adorned with “Strawberry Anemones” (not actually an anemone species but a “corallimorph”. ©2017 Jackie Hildering.

Indeed, even though decorator crab species look like walking gardens, often what they attach are not algae but other animals – hydroids, sponges and bryozoans.

Additional bonuses of carrying other organisms on your back may be:

  • You have potential snacks within a pincher’s reach.
  • Your camouflage allows you to get closer to your prey.
  • You are carrying weapons!

From A Snail’s Odyssey: “Apart from passive camouflage from potential predators, other functions of the behaviour may include disguise for closer approach to prey, and provision of tools for active defense, such as a branches of hydroids containing functional stinging cells or pieces of sponges or tunicates containing toxic chemicals.”

Graceful Decorator Crab with snippets of sponge attached to his/her carapace (Hooded Nudibranchs in the background). This individual realized it had been seen and switched to the defence strategy of looking big since “so many fish predators are limited by the size of their mouths” (Source: Crabs and Shrimps of the Pacific Coast); ©Jackie Hildering.

Note too that not all growth on the back of crabs is the result of decorating and remember that crabs moult, crawling out the back of their shells in order to grow. Also from A Snail’s Odyssey:  “In some cases these camouflagings result from settlement of spores and larvae . . . . Passive buildup of growths is greater with increasing age as moulting frequency decreases.  Also, in many species there is a final or terminal moult which, if the species’ exoskeleton is receptive to settlement of larvae and spores, leads to an even greater build-up of cover.”

Graceful Decorator Crab adorned with (and atop of) Glove Sponge. ©Jackie Hildering.

“Spider crab” (superfamily Majoidea) species are the ones that most often adorn themselves. From Greg Jensen‘s Crabs and Shrimps of the Pacific Coast: “Many spider crabs . . . mask themselves with algae or encrusting organisms so that they can hide in plain sight. The decorator crabs are equipped with curved setae much like the hook part of Velcro fasteners: after shredding material a bit with their mandibles, they press it into place. The largest species tend to stop actively decorating once they outgrow most of their predators.”

Crab predators include the Giant Pacific Octopus and fish species like Cabezon, some rockfish, Surfperch, Wolf Eel and the Staghorn Sculpin. Of course, at low tide, birds and mammals are also predators.

Hoping this adds to the wonder, connection and respect for our marine neighbours. Enjoy the rest of the show!

[For research on decorator crabs with great diagrams explaining how how attachment occurs see this link.]

Well that’s unique! Decorated with Sea Vases (species of tunicate). ©2017 Jackie Hildering.

Try not to smile!

Another Graceful Kelp Crab adorned with Raspberry Hydroids.

Here you can even see where the Graceful Decorator Crab has clipped off bits of sponge. AND s/he’s in the act of attaching clippings. ©Jackie Hildering.

Longhorn Decorator Crab. ©Jackie Hildering.

Heart Crab (I THINK) – not likely to have decorated itself but rather this is the result of the settlement and accumulation of organisms = a walking ecosystem. ©Jackie Hildering.

Graceful Kelp Crab with adornment of Sea Lettuce. ©Jackie Hildering

Graceful Decorator Crab in front of a Painted Sea Star. S/he had just moved from being camouflaged among kelp to moving in front of the sea star. ©Jackie Hildering.

This Graceful Decorator Crab has adorned him/herself with bits of Barnacle Nudibranch egg masses for camouflage. You can see the egg masses behind the crab.

Decorator crab species in the NE Pacific Ocean include:

  • Graceful Decorator Crab – Oregonia gracilis
  • Graceful Kelp Crab – Pugettia gracilis 
  • Longhorn Decorator Crab – Chorilia longipes
  • Other species too will sometimes put a bit of camouflage on their rostrum e.g. Northern Kelp Crab – Pugettia producta