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

Tunicates – Your Distant Cousins?

Here’s one of your highly evolved and wonderfully unique marine neighbours.


Five colonies of Mushroom Tunicate. I believe this is Distaplia occidentalis.

Mushroom Tunicates are one of the many species of tunicate in the NE Pacific Ocean. The tunicates, as simple-looking as they may seem to you, are our closest invertebrate relative. That’s how complex their anatomy is.

From Dr. Laura Cole quoted from the Smithsonian blog Tunicates — Not So Spineless Invertebrates “About 3,000 tunicate species are found in salt water habitats throughout the world. Although tunicates are invertebrates (animals without backbones) found in the subphylum Tunicata (sometimes called Urochordata), they are part of the Phylum Chordata, which also includes animals with backbones, like us. That makes us distant cousins . . .  What unites these diverse groups and makes them our relatives? All animals in the Phylum Chordata have a notochord, a flexible backbone like structure, at some point in their lives.”

So here are some fascinating facts that may influence how we perceive organisms that look very different than we do. 

Tunicates have a unique exoskeleton called a tunic.


Photo showing the diversity of colour in Mushroom Tunicates.

Some tunicate species are solitary, living as distinct individuals. Others, like Mushroom Tunicates are COMPOUND tunicates where individuals live together in the colony, within one tunic. The individuals in the colony are called zooids. The zooids have specialized functions that can serve the collective colony. In this species each individual has its own incurrent siphon and pharynx (throat-like structure) to bring in water to filter feed. The individuals in the colony share digestive, reproductive and circulatory organs and excurrent siphons (to carry water out).

Oh, and by the way, tunicates are the only animals known to have a heart that can pump in two directions; they can reverse the direction of circulation.


Photo shows how compound tunicate colonies share a stalk. 

Tunicates are hermaphrodites where reproduction occurs both by cross-fertilization and self-fertilization. The fertilized eggs are brooded inside the colony in a brood pouch and the timing of when parents hatch out the relatively large tadpole-like larvae has been found to be influenced by light (morning appears to be preferred).  

Some species of tunicate have been found to have bacteria associated with them that provide chemicals that ward off predators and disease-causing microorganisms. You can imagine the human interest in how these chemicals might help our species fight off pathogens. 

And in case this all isn’t wild enough, colonial species of tunicate are known to regenerate their entire body from a group of cells named blood cells. This too makes them of great interest to we humans, who are tunicates’ distant relatives, but evolved to NOT be able to regenerate body parts.

Further information from Dr. Laura Cole, from her much-valued resource  “Tunicates — Not So Spineless Invertebrates”

The most common tunicates are sometimes called sea squirts because when touched or alarmed by a sudden movement, their muscles contract and the water in the animal shoots out. They are sessile after their larval stage, meaning that they remain attached to a hard substrate, such as dead coral, boat docks, rocks or mollusk shells, all of their adult lives. The name “tunicate” comes from their outer covering, called the tunic, that protects the animal from predators, like sea stars, snails and fish. Unlike the sessile sea squirts, other kinds of tunicates float in the water their entire lives. The salps and pyrosomes are mostly transparent tunicates that look a bit like jellyfish floating freely—some pyrosomes have be known to reach 60 feet (18 m) in length. Much smaller but still visible to the naked eye are the larvaceans—tiny tadpole like creatures that live inside a small house that they build and regularly replace.

[Note there are two related The Marine Detective blogs: (1) “Pyrosomes! Say What?” at this link and (2) “Otherworldly Drifter. Mind Blown” at this link.]

What unites these diverse groups and makes them our relatives? All animals in the Phylum Chordata have a notochord, a flexible backbone like structure, at some point in their lives.

Sea squirts have a notochord only in the larval stage which they use to swim and find an ideal place to attach—one that is bathed in particle-rich waters, since like all tunicates they are filter feeders and rely on water currents for food and nutrients. Once a good location is found, the larva attaches with a suction-like structure and metamorphosis begins. The notochord shrinks and gets absorbed into the body as the animal changes into an adult, and the tunic forms as the transformation occurs. The animal will then spend its days feeding on tiny particles from the water, primarily bacteria. 

There are two types of sea squirts: solitary and colonial. The solitary animals live separately all of their lives inside of their tunics. Each has two siphons—the oral siphon that receives the nutrient rich current and the atrial siphon that excretes the waste. Colonial species share a common tunic and sometimes also share the atrial siphon. Colonies of sea squirts are formed as a result of budding—when the larva settles and changes into the adult form, it then splits (or buds) to produce new individuals, called zooids. Colonies can be a few centimeters to several yards wide depending on food availability and predation.  

Sea squirts don’t look much like us as adults on the outside, but they have a digestive system similar to ours—with an esophagus, stomach, intestines and a rectum. But there are plenty of other differences. Unique to the benthic tunicates is a heart that reverses its beat periodically. It’s still a mystery to researchers why the tunicate heart will circulate blood through the heart in one direction and then switch to the opposite direction, or if the ability gives them some sort of advantage. 

On land, we don’t encounter sea squirts that often, although they are increasingly eaten by some Mediterranean, Asian and South American countries. Not only is the soft body inside of the tunic eaten, but the tunic itself can be pickled and enjoyed later. Compounds from several tunicate species could be useful in medical treatments for diseases ranging from cancer to asthma. Tunicates act as ocean purifiers, since they consume bacteria, and they can send a message that heavy metals are present in ecosystems where they are found, since they absorb metals like zinc and vanadium. Because they like to attach to hard surfaces, sea squirts are often found on the underside of boats, or inside motors, where they can wreak havoc on equipment, and some have become invasive species after being transported from their native ranges. Their relatives the pyrosomes, also called sea pickles, sometimes wash up in large numbers on the shore and are known for their bioluminescence. 

Like with many a large family, most of us don’t know about these distant relatives found in the ocean, but that doesn’t mean they aren’t worth keeping an eye on.”

Photos of other species of tunicate living in the NE Pacific Ocean.
Note that there are many more species than what I show here.

Solitary tunicate species: Pacific Sea Peach, Halocynthia aurantium, to 15 cm tall. Species like this have led to tunicates sometimes being referenced as “Sea Squirts” due to to larger, solitary species of tunicate having the “tendency to squirt seawater periodically from the main branchial siphon to back-flush sediments, other indigestible matter, and small animals from the filtering basket (about 10 times per hour in some species). Source: Snail’s Odyssey.
Another Pacific Sea Peach.
Solitary tunicate species: Glassy Tunicate, Ascidia paratropa to 15 cm tall. 
Solitary tunicate species: Sea Vase. In this photo, multiple individuals are “reaching” out of a crack in a wooden piling. Ciona savignyi to 15 cm tall.
Solitary tunicate species: These Transparent Tunicate have a problem. This species gets invaded by a wicked parasite (as opposed to all those gentle and meek parasites out there) . . . the Spotted Flatworm! This species of flatworm curls up, sneaks in through the tunicate’s branchial siphon, unrolls, eats the tunicate’s internal organs over 3 to 7 days and then moves on, leaving behind the empty tunic. They are species specific parasites, apparently specializing in invading Transparent Tunicates. The dark coil you see here is the waste inside their rectums. Transparent Tunicate = Corella willmeriana to 7.5 cm tall. Spotted Flatworm = Eurylepta leoparda to 2.5 m.
Alabaster Nudibranch atop Orange Social Tunicates (Metandrocarpa taylori.
Light-Bulb Tunicate. Clavelina huntsmani to 5 cm tall.

Stalked compound tunicate – possibly Distaplia smithi

Compound tunicate species: Red Ascidian. Aplidium solidum to 20 cm across.

Compound tunicate species: Lobed Compound Tunicate. Cystodytes lobatus, irregular size and shape, can be more than 50 cm wide.

Compound tunicate species: Lobed Compound Tunicate. Cystodytes lobatus with a feeding Orange Sea Cucumber.

Compound tunicate species: Lobed Tunicates and Mushroom Tunicates (and a whole lot more) 🙂

Compound tunicate species: May be Pale Mushroom Compound Tunicate. Aplidiopsis pannosum to 5 cm wide. 
Perspective into the siphons of a Broadbase Tunicate (Cnemidocarpa finmarkiensis to 5 cm across).
Hairy Tunicate (Boltenia villosa to 10 cm tall) near Broadbase Tunicate.

Sources: 

Invasive Tunicates

This is an example of an invasive tunicate species now found off the coast of British Columbia (and many other places). .
It’s the Lined Compound Ascidian, Botrylloides violaceus. All the other species shown here are not invasive

Super Mom! Up to 300 young under her care.

Last updated: April 2026
Initially posted for Mother’s Day.

These are Brooding Anemones (Epiactis lisbethae to 8 cm across).

Brooding anemone 1

She may not have a backbone, but she’s a Super Mom!

As many as 300 young can be clustered around her in up to 5 rows, benefitting from the protective canopy of her tentacles which contain stinging cells (nematocysts). The offspring remain here until big enough to stand a good chance of surviving on their own. They then crawl toward independence, claiming their own piece of the ocean bottom.

I am awestruck by this species’ beauty and reproductive strategy. It is also a reminder of how little we know about marine species that the Brooding Anemone was not recognized as a distinct species until fairly recently (1986), and it still so often gets confused with the Proliferating Anemone (Epiactis prolifera).

I share my marine “detectiving” about this species with you to provide a further example of how extraordinary our marine neighbours are and maybe, thereby, help inspire greater conservation efforts.

But yes, the timing of the blog is no accident. It may be that reflection upon an anemone Super Mom stimulates thought about our human mothers – just in time for Mother’s Day.

So here goes . . . bear with me as I build to clarifying the reproduction of our featured species.

© 2013 Jackie Hildering one time use only-4240156

Anemones have many reproductive strategies.

For many species, reproduction can be asexual as well as sexual with strategies like budding off offspring; splitting into two; or pedal laceration where a torn piece of the bottom of the anemone can grow into another anemone!

Some species are hermaphrodites with highly diverse ways by which offspring develop into adults.

In species that have separate sexes, many are broadcast spawners where Mom and Dad release their eggs and sperm into the ocean around them. Fertilization and development thereby happens in the water column.

Then, for only some 20 species of the world’s more than 800 kinds of anemone, there are those in which the female captures the males’ sex cells as they drift by and draws them into her digestive cavity to fertilize her eggs. She “broods’ her young.

Some such anemone species are internal brooders.  The young develop inside Mom until they hatch and are expelled into the water column as planktonic larvae.

But then there’s Super Mom – the Brooding Anemone (Epiactis lisbethae). She’s an external brooder.

After she has fertilized the eggs inside her digestive cavity with the sperm she has captured, the young develop inside her until they hatch into planktonic larvae. THEN, they swim out of her mouth, settle on her body under the tentacles and grow into little anemones that feed themselves.

When the offspring are big enough to stand a good chance of survival without the protection of Mom’s tentacles, they shuffle away to independence, leaving space for next season’s young.

The brooding anemone’s young are all of the same generation and are therefore all about the same size.

However, there is a second externally brooding anemone species in the eastern North Pacific where you most often see young of different sizes huddled under Mom’s tentacles. This species – the Proliferating Anemone (Epiactis prolifera) is the one that very, very frequently gets confused with the Brooding Anemone.

Proliferating anemone.
Proliferating Anemone with young (Epiactis prolifera). Often confused with the Brooding Anemone (Epiactis lisbethae). 

I have strived to clarify the many differences between these two externally brooding anemone species in the table below but to summarize: the Proliferating Anemone is smaller and does not have striping all the way down the column; adults are hermaphrodites; breeding happens year round; there are far fewer young clustered under mom’s tentacles; and they start off there as fertilized eggs, not as free-swimming larva.

The main similarity between these two species is and yes, I am going to use a tongue twister here since I believe it is inevitable when discussing anemones: with anemone mothers like these, baby anemones are protected from their anemone enemies!

Now off you go, share some ocean love with a Super Mom!

There are so many human females out there worthy of awe.

Where, were we to consider how many young they have shielded and helped to independence, the number might well be 300 or more. 

brooding vs. proliferating table
Click to enlarge. Table summarizing the differences between Brooding and Proliferating Anemones.
Brooding Anemone with young (Epiactis lisbethae) – all the same age. ©Jackie Hildering.
long-horizontal-001
See those distinctive tentacles, one coming from each Brooding Anemone? I don’t know what is happening here. This species does not have a penis and are reported not to have acontia (specialized stinging cells).

Sources:

Hermit Crabs with Sponge Homes

Please see photo below.

You are looking at two animals, not one. 

Alaskan Hermit Crab = Pagurus ochotensis to 5.3 cm long. The yellow eyes and “sheen” on the legs help in IDing this species. See how uniquely reflective the legs are? This species often lives in a shell made by a Northern Moon Snail (until a suberites sponge dissolves it away 😉 ).

 

This is an Alaskan Hermit Crab (who resides in front of Port McNeill, not Alaska).

Living on his/her back is a “Hermit Crab Sponge”.

This sponge species (Suberites latus) settles on the shell home of some hermit crab species and can completely dissolve the shell away.

Having a sponge home has its advantages. It is light. Also, the sponge will grow whereby the hermit crab need not find a new home as would be the case if it outgrew a shell home.

But, it can be awkward to tote around when it gets really big. See an example below.

Bering Hermit with a huge suberite home relative to its size. (Pagurus beringanus to 2.6 cm).

 

 

Yes, the hermit crab could leave the sponge and get another home if one were available. But, there is risk when outside your home, be it ever so brief.

Another disadvantage is when you have unwelcome house guests.

See below to get a sense of the inconvenience when a sponge predator crawls on your back.

 

Close-up on the inconvenienced Mud Hermit Crab.

From top to bottom: the big yellow animal is a Monterey Dorid (nudibranch species – gills are on left). This nudibranch is feeding on the Hermit Crab Sponge (tan colour) and then, see the tiny face? That’s a Mud Hermit Crab who isn’t going anywhere for a little while (Pagurus capillatus to 4 cm).!

Here’s another Mud Hermit Crab. See the bite out of the sponge? I initially found this individual upside down. The resulting photo of the underside of the sponge gives you a sense of how the sponge is shaped to the hermit crab’s body.

 

Note too how all the hermit crabs included in this blog have one claw bigger than the other?  This is the case for many hermit crab species and it allows them, when they retreat into their home, to seal off the opening to the shell or sponge with the bigger claw. They close the door to their home.

In the photo below, see how the larger claw seals off the hole for the hermit crab on the right? I suspect this interaction captured in this photo more about mate selection that it is about home envy.

 

 

I hope this “who is sponging off who” interaction provides some wonder for you at a time when safety in homes is such a reality for our species too (re COVID-19). 

Be safe whatever, and wherever, your chosen home.  💙 

The Hermit Crab Sponge is Suberites latus to 20 cm long, 6 cm wide and 4 cm high.
Source for these dimensions is “Beneath Pacific Tides” by Greg Jensen.

 

Bluespine Hermit with sponge home  (Pagurus kennerlyi to 3.5 cm long)

 

Juvenile Alaska Hermit who will benefit from the sponge growing bigger.

 

Bering Hermit Crab interaction. This too is more likely about dragging around a potential mate.

Slugs that Fly? The Great Winged Sea Slug.

Last updated: May 3, 2026
The information below is about 3 species of headshield sea slug (Order Cephalaspidea) that have similar egg masses. All three also have a very thin internal shell (bubble shell).

1. Great Winged Sea Slugs (the ones known to fly)
2. Albatross Aglaja
3. Spotted Aglaja

Great Winged Sea Slug

Gastropteron pacificum to 4 cm long.

Here’s a species that deserves the descriptor “Great” without doubt – the GREAT Winged Sea Slug.

I will never forget the first time I saw one of these tiny sea slugs “flying” underwater.  My brain came close to exploding. I did not know of their existence prior to one flapping past my mask.

Dive buddy Natasha Dickinson pointing at a Great Winged Sea Slug.

Gastropteron pacificum is usually no bigger than your thumbnail. Maximum length is ~2 cm long and with “wingspan” to 4 cm. The species is also referenced as the Pacific Wingfoot Snail and the Pacific Batwing Sea Slug. But, as mentioned, I prefer the reference to their greatness.

Just marvel at how they can propel themselves, as captured in this video.

I will ALSO never forget the first time I saw them spawning, so many of them on the sandy ocean floor, their egg masses expanding to be bigger than they are.

I try to document this every year, looking in areas with sand in from late March into May. I have found them, and their eggs, as shallow as 2m depth.

And sure enough, on March 31st, there they were again. They are gathering to mate!

March 31, 2020 – “Beach Camp” near Port McNeill at only about 3m depth.

The photos below show you what the peak of the spawn looks like. Photos are from May 26th, 2019. Just look at the number of them! How do they find one another? How many eggs in an egg mass? So many questions!

I bet you also want to know how it can be that their masses of fertilized eggs are bigger than the sea slugs themselves. I presume the masses must expand with seawater but  .  . .  I do not know.

As is the case for most terrestrial and sea slugs, Great Winged Sea Slugs are simultaneous hermaphrodites whereby both parents become inseminated and lay eggs. It’s a great strategy to maximize chances of reproductive success when finding a mate is particularly challenging and your babies hatch into the planktonic soup of the ocean.

Among my many wonderings about this species is: Why have I never seen Great Winged Sea Slugs swimming during the time they are aggregating to mate?  I learned from research by Claudia Mills in Friday Harbour (published in 1994), that only sexually mature animals swim AND that they were only observed doing so between September and February i.e. not while mating.

Why swim? In may work well to escape annoying divers and/or bottom feeding fish like Ratfish. The timing suggests that it allows for population dispersal – spreading out for food and/or mates. You would think that the fact that hatch as plankton would spread them out enough. Also, HOW do they then assemble in numbers like this? Is it possible that these sea slugs smell one another’s scent trails even in the ocean?

You can see faint trails here.

Please know that this species IS a sea slug but it is NOT a nudibranch. Great Winged Sea Slugs don’t have naked gills and adults do have an internal shell when adults. Great Winged Sea Slugs belong to the group of sea slugs known as “bubble shells” of the order “Cephalaspidea”. You can even see the bubble shell in some of these images.  Ronald Shimek creatively described these sea slugs as having “an internal shell that looks quite like a soap bubble and is about as durable.”

The wing-like structures are called parapodia. When the sea slug is not swimming, these “wings” wrap around the body forming a water-filled cavity. See what looks like a siphon? Part of the “head-shied” folds into a siphon directing water into the cavity. There’s also an exhalant siphon.

The photo above is from the first time I ever noted this species. I was able to follow one as it drifted to the bottom and then saw the siphon appear. This added to the sensation that my brain was going to explode with awe. I shared the photos with experts and learned that, at that time (2007) it was not known what any members of the family feed upon. This added to my appreciation / understanding of how little is known about marine species that are even common and in the shallows. Bill Rudman responded with “I suspect they may feed on small flatworms or other invertebrate with no hard parts – but that is just a guess.” Apparently Gastopteron are known to feed on detritus and diatoms but it a laboratory setting, To my knowledge, there has not been confirmation of the diet of the species when in the wild.

More about the eggs via Jan Kocian: ”  Anne Hurst (1967) described the egg masses and veligers of Gastropteron pacificum. She considered the egg mass to be of “Type C,” that is, “in the form of an ovoid or globular jelly bag attached by a jelly string. Ths is common amongst cephalaspideans” (Hurst, 1967: 256). The egg mass of G. pacificum “is almost globular and of clear jelly. It contains widely separated rounded capsules containing spherical pink eggs. The smooth-walled capsules each have a short string-like protrusion from one point on their surfaces and this does not appear to be attached elsewhere. As the eggs develop to form a ball of cells, the pink colour becomes concentrated and at one side of it is a group of yellowish cells, the whole being surrounded by a narrow layer of greenish cells” (Hurst, 1967: 268) . .  . Egg capsule dimensions range from 181-220 µ, and the animals take 14-15 days to hatch.”

Regarding diet, when I asked Bill Rudman of the Sea Slug Forum in 2007 what this species fed on, the answer was: ” . .. Gastropteron is one of the largest species in the family. At present we have no idea what any species feeds on, so this species might be easier than many to catch feeding. Can you put it on your ‘to do’ list? It would be very interesting to know. I know of no identifiable stomach contents being reported so I suspect they may feed on small flatworms or other invertebrate with no hard parts – but that is just a guess.”

I hope, dear reader, that these words and images offer an additional chance to get lost in the natural world for a little bit. It offers me such comfort to see the steady flow of the natural world around me – from the courting of song birds, to the emergence of plants, and the mating of sea slugs.

Know that, right below the surface, there’s a world or greatness  .  .  . where slugs fly.

Note that if you see similar egg masses in the intertidal zone,I believe they are more likely to be from one of two other sea slug species that are also headshield sea slugs (order Cephalaspidea)
– Albatross Aglaja or Spotted Aglaja. See below.

Albatross Aglaja

Melanochlamys diomedea to 1.5 cm long.

So often under the sand. Known to feed on nematode worms and kinorhyncha, aka mud dragons (Source: Zamora-Silva and Malaquiasm, 2016). The former common name of this species was the Diomedes’ Aglaja.

Albatross Aglaja laying eggs. You can get a sense of how small it is relative to the size of the grains of sand.
Albatross Aglajas crawling through the sand in the shallows.
Albatross Aglaja laying egg mass – you can just see a little bit of the sea slug in the centre of the egg mass.
Yeah! One above the surface whereby you can see the “headshield”,
See the tracks that help you find the Albatross Aglajas? Arrows indicate where three of them are amid their egg masses.

The species has been found in Norway which was not part of its known range. Malaquias et al, 2025 put forward that: “The exact origin of the specimens remains unclear but the absence of records from the northwestern Atlantic coasts of Canada and USA, combined with the increase in ship traffic across the Canadian Arctic support the hypothesis that a European population was introduced via shipping routes connecting the northeastern Pacific through the Arctic Northwest Passage.”

Karolle Wall has made the exceptional observation of one swimming in a similar way to Great Winged Sea Slugs.

Spotted Aglaja

Aglaja ocelligera to 3 cm long.

Usually also under the sand. Said to feed on other bubble shell sea slugs, which may include the Albatross Aglaja. Both the Spotted Aglaja and Albatross Aglaja do not have a radula (rasping tongue) whereby they are said to suck in their prey whole.

A rare good look at a Spotted Aglajid since they are usually burrowed in sand. Notice how one tail is longer than the other.
Two Spotted Aglajids above the sand, presumed one is following the other’s scent trail to get together to mate.
A Spotted Aglajid laying eggs! “Aglajids lay their eggs in the most interesting way. They release the egg stream around their rotating body, creating a coil or tube-like mass. They then dive into the sediment placing an anchor so the eggs, above, won’t wash away.” Source: Dave Behrens.
Observation from Keith Clements posted on Facebook, March 20, 2024.

Sources:

For an additional blog about another bubble shell sea slug in the NE Pacific Ocean see – “Shelled Sea Slug! A small mystery solved.”

Classification of Sea Slugs 

My attempt at summarizing the cassification of the group to which sea slugs belong.
Last updated 2020-04-17. Source: World Register of Marine Species.

Regarding the photo below:
The Opalescent Nudibranch is a nudibranch.  Nudibranchs DO have external gills (hence “nudi” = naked and “branch” = gills). Adults do NOT have an internal shell.
The Great Winged Sea Slug is a “bubble shell” sea slug (Cephalaspidea). They do NOT have naked gills and adults DO have an internal shell.
There! Now don’t you feel better knowing that: (1) Not all sea slugs have naked gills and hence not all sea slugs are nudibranchs; (2) However, all nudibranchs are sea slugs.

Preoccupied with Parasites

Preoccupied with parasites!

That’s not usually a good conversation starter is it?

But, read on. It’s worth it! If you are fascinated by adaptations and the interconnectedness of species . . . even when it involves parasites.

These are Transparent Tunicates (aka Transparent Sea Squirts). They are not parasites. They are highly evolved animals with a primitive backbone. They take in food particles through one siphon in their strong “tunic” and expel waste through the other siphon. See the siphons?

The dark you see here is the waste inside their rectums. Yep, they are filter feeders and clearly take in some sand too. What’s this then about parasites?

This species gets invaded by a wicked parasite (as opposed to all those gentle and meek parasites out there) . . . the Spotted Flatworm! This species of flatworm curls up, sneaks in through the tunicate’s branchial siphon, unrolls, eats the tunicate’s internal organs over 3 to 7 days and then moves on, leaving behind the empty tunic.

They are species specific parasites, apparently specializing in invading Transparent Tunicates. The following photos clearly show you the Spotted Flatworm presence there and the tunicates are now mere shells of their former selves.

All the internal organs are gone in the heavily invested individual in the photo below.

In having the privilege of learning even from individual animals by diving the same areas frequently. I recently saw the progression for individual Transparent Tunicates and the Spotted Flatworms that had invested them. The following photo is from March 1st, 2020. I’ve now added arrows to show the parasites.

The following two photos show you reality  24 days later. The originally invested Transparent Tunicates are dead and the Spotted Flatworms have moved into their neighbours.

Below is another perspective on the same individuals.

I truly hope that in these times where our own species is facing extreme challenges, that this information still creates awe, connection and respect for the lives of others. Maybe it’s more important than ever.

Wishing you health, resilience, and strength of community.

Transparent Tunicate = Corella willmeriana to 7.5 cm.
Spotted Flatworm = Eurylepta leoparda to 2.5 m.

___________________
Photo showing what a Spotted Flatworm looks like when not in a Transparent Tunicate.
‎Marine Mysteries.‎001

Mystery Worm

The species of necklace-worm in the following two photos has, to my knowledge, not yet been identified by science. My latest sighting of it was yesterday.

I am sharing the images to illuminate anew how little we know even of species in the shallows.

I have only documented this species 3 times and in each case it has been in less than 8 metres / 25 feet  of water. Interestingly, it was near Proliferating Anemones in each case which makes me wonder if the might prey on them. I am perplexed too by the slime encasements evident in the second photo.

I believe it has also only been documented around the Plumper Islands area off NE Vancouver Island.

I have relayed the observations to polychaete worm experts.

 

To be clear, I did not discover the species. 

I have only found individuals of this necklace-worm that has previously been recognized by experts as being an unidentified species.

In Andy Lamb and Bernie Hanby’s “Marine Life of the Pacific Northwest”, it is species AN22. They state: “While diving the Plumper Islands near Port McNeill, BC, we found this mystery necklace-worm. Significant numbers of this small (5 cm / 2 in long) creature were crawling about in the open, completely exposed. Such behaviour would seem to invite predation. Unfortunately, without a specimen . . . accurate identification is not possible. Detailed examination of the palps, teeth, cirri (finger-like projections) and chaetae (bristles) are required for species determination . . . It looks diminutive, but this mysterious worm is actually large compared to most necklace-worms.” Further from their update on KnowBC; “Some interesting observations can be made, however. The tentacular cirri near the head are much longer than their dorsal counterparts in the middle of the body: the latter appear to be shorter than the worm’s body width. It is not clear, though, whether these cirri are annulated (ringed) or smooth. The specimen’s eyes are evident as are some sensory organs located just behind them. Intriguing features are the two faint but obvious transverse structures on each segment that appear to be ciliated (hairy).”

Oh and because truth, humility and self-mockery are virtues I try to stand for, know that I had no idea I had photographed the species yesterday. I only saw it when I was processing my photos of the Proliferating Anemones. There are good reasons I dive with a magnifying glass.

 

Below, please find photos of just a few of the other species of marine worm that I have photographed around NE Vancouver Island.

I am sharing these to add to the wonder of worms found in the NE Pacific Ocean.

#1 Windmill Bamboo Worm
Praxillura maculata to 25 cm long.

This species makes 6 to 12 “vanes”/spokes at the end of its protective tube and then strings a web-like net of mucus between to capture bits of food. After a time, the worm comes OUT of its tube and eats the mucus and food! Yep, it seines for its dinner! See this link for photos by Ronald Schmek of the worm coming out of its tube to harvest dinner.

#2 Basket-Top Spaghetti-Worm
Pista elongata to 21 cm long

The Basket-Top Spaghetti-Worm builds a tube AND A BASKET from bits of debris and extends its tentacles through the basket to feed. So little is known about it.

From Lamb and Hanby: “The lower part of the tube, where the worm resides, is coated with shell fragments and pebbles. Is the purpose of this extravagant tube solely to camouflage and protect the worm . . . or to increase its access to food? The worm extends its long tentacles through the basket to gather food particles selectively . . . The basket-top may also function as a sieve, filtering out particles brought by currents. Elevating the tube above the rocky substrate may provide the elongate, and tree-like branchia (gills), hidden in the basket, with a good supply of oxygenated water.”

#3 Calcarious Tubeworms 

There are a variety of Calcareous Tubeworms species in the NE Pacific Ocean. I believe those in the following photos are “Red-Trumpet Calcareous Tubeworms” (Serpula coumbiana to 6.5 cm long).  You’ve probably deduced that with that large surface area, they dust for plankton snacks with their crowns. These structures also allow the animals to respire.

See the trumpet-like structures (which need not be red as the common name suggests)? That is the “operculum”. It functions like a door that pulls closed after the tubeworm retracts. Thereby the worm is further protected in its hard, shell-like tube of a home

I am always thrilled when I succeed in photographing this species since, with any disturbance, the crown Immediately retracts as of result of they eye spots detecting the change in light / shadow.

#4 Jointed Three-Section Tubeworm
Spiochaetopterus costarum to 48 cm long

Jointed Three-Section Tubworms are filter feeders that create mucus bags inside their bodies through which water is passed due to the beating of cilia. As the water passes through the mucus, plankton and detritus particles are sieved out. The long polyps you see in my first photo below, remove the pellets and keep the opening of the worm clear. Notice how thin the worm is and therefore how spacious the tube it has constructed? The second photo shows you what the pellets look like. 

The nudibranch species in the first images is an Opalescent Nudibranch which is likely feeding on a species of hydroid on the outside of the worm’s tube.

The nudibranch species in the third and fourth photo is Himatina trophina which not only feeds on hydroids on the outside of the tube but also, as you can see, lays its egg ribbons there.

#5 Slime-Tube Feather Duster Worms
Myxicola infundibulum to 9 cm long

This species can also detect shadow and retreat into their mucus homes with lightning speed. All you then see is the jiggly jello-like top of their tubes. (Yes, it took me a long time to get a photo of them!) Where other marine tube-worms make a parchment or shell-like tube, worms of the Myxicola genus secrete themselves a mucus home. “Myxicola” in fact translates into “living in slime” so don’t name your child that . They suspension feed on plankton and other bits of organic bits with their funnel-like crowns ( = “radioles”).

#6 Feather Duster Tube-Worms

It is very easy to see why these are known as “feather duster” worms.  Their crowns have huge surface area to “dust” the ocean for food. They live in parchment tubes and feed on plankton with their bushy crowns.

The banded blue and purple ones with the thicker tubes are the Vancouver Feather-Duster (Eudistylia vancouveri to 25 cm long). The pink, grey and tan ones are Split-Branch Feather-Dusters (Schizobranchia insignis to 15.8 cm long). 

Vancouver Feather-Duster and Split-Branch Feather-Dusters. See the nudibranch egg mass under the biggest Plumose Anemone? Those are from a Monterey Dorid.

 

Split-Branch Feather-Dusters (Schizobranchia insignis to 15.8 cm long). 

 

Vancouver Feather-Duster (Eudistylia vancouveri to 25 cm long).

#7 Sea Nymphs / Nereidae Worms

There are more than 20 species of nereida worms in the NE Pacific Ocean and the one that I am asked about most often is the “Giant Pile Worm” (Alitta brandti). It is indeed giant at up to 1.5 long and causes wonder and confusion; even getting misidentified as being an eel instead of a worm.

The video below shows a male spawning at the surface.

 

Octopuses Shed Their Suckers!

So cool, so cool, SO COOL.

While I was diving today, I saw these structures, like large snowflakes drifting out of a crack between two rocks.

And I knew there had to be a Giant Pacific Octopus there BECAUSE this is the skin at the end of the octopus’ suckers.

Octopuses shed this skin periodically and, possibly, from all their suckers at the same time! The skin grows continuously.

With Giant Pacific Octopuses having about 2,000 suckers (up to ~2,240 in females and 2,140 in males), you can imagine how many of these were drifting out of its den as the octopus exhaled, causing an upward current.

This skin is referenced as the sucker lining or “chitinous cuticle” and you can deduce from the photo below how the skin being shed would be of varying sizes.

 

I could peer into the crack and see the octopus that was shedding but s/he was too deep into the den to be able to get a photo.

How wonderful it would be to be able to provide you video of an octopus shedding its suckers in the wild. But, not surprising, it is easier to capture this with octopuses in captivity.

Below is a video of a captive Giant Pacific Octopus named Marylyn shedding her sucker linings (Video source: Christie Rajcic, “Octopus Shedding Suckers”).

 

I hope this adds to your sense of wonder of our marine neighbours. It also provides a whole new association to the words “So long suckers!” 😉

It’s difficult to explain the joy it gives to not have disregarded these little white bits but to know they were a clue to where there was an octopus.

Oh, and if you enjoyed this, you definitely will want to benefit from my life-enhancing blog “How Octopuses Poo“.

For you super nerds (hello!), the cuticle covers the “infundibulum”. See images below from “A Snail’s Odyssey“.

Sources:

Better Vision – New Year Thoughts and Octopus Eyes

[Update in 2021: CLEARLY I had no idea what a globally and colossally crap year 2020 was going to be when I wrote this blog. May the thoughts and information about octopus eyes still provide vision 🙂 ].
 
Here’s an unlikely combination of introspection and natural history. It’s what results when you bring together a photo of a Giant Pacific Octopus’ eye with the bad word play of “2020 vision” regarding the new year.

Introspection: In a human lifetime, you don’t get to cross the threshold into all too many decades. Like many of you, it makes me take pause . . . wanting to understand where we are and how to move forward with focus. It’s what happens when you want to make sense of a world which appears to have increasing numbers of cartoon-character-like heads of state. It makes me think about the state of heads, and how to find one’s way without despondency, denial and inaction.

I write these words largely to solidify my resolve and vision in this decadal transition but share them here in the hopes that they may be of use to you.

Better vision for better futures:

  1. The paradigm: Realizing why there are forces in the world who would rather flirt with the health of future generations than undertake action that would benefit their own grandchildren. They are those who have benefited the most from lack of equality, fossil-fuel use, rampant consumerism, and use of disposables. Despite the enormity of their power, positive change is happening and in the death throes of the paradigm, the very nature of truth is being challenged. When one shouts loudly, it is not likely they are more correct. It is an attempt to drown out the truth. They are the spasmodic utterances of the entitled. The aims are confusion, distraction, discontent (just keep buying more little girl and happiness will be yours), despondency, overwhelm and (of course) the blunt tool of FEAR. The hope is that we shut down and not notice the steps forward toward a paradigm based on greater equality and sustainability.
  2. Less is more: These are words I have shared so often. Above a true level of need, using less is not about loss. It’s about gain. The more we steer away from the myth that owning more and/or bigger is best or that it equates to “success”, the more liberation we have from being enslaved to $. We do know where true happiness lies. It is where there is greater sense connection, health and time for who and what we love.  What a world it would be if more of us saw that gain and realized just how empowered we are to create change through our consumer and voter action. Using less fossil fuels, dangerous chemicals and disposables positively impacts so many socio-environmental issues.
  3. The way forward: You’ve seen it haven’t you? The uprising, the unblinking truth . . . the power of youth who know the way. How excited I am for power shifting further toward them, their technologies and lifestyles fuelled by values of equality and sustainability. In no way does that mean we stand idle and wait for them to be of the age to vote. For me it is to be in service of them, the next generation. It is to help others see the way, to know their place in nature, to know their power, to find their voice, and to shield them from despondency, and fear.  

And here’s the natural history and marine mystery bit relating to the photo of the octopus’ eye (note that she was in her den and that I used a zoom lens).

Octopus vision:

You see that the pupil’s shape is very different from ours. Their retina is very different too.

Octopuses and other cephalopods have only one kind of photoreceptor cell while we have rod cells and three types of cone cells allowing us to see in colour. So how can cephalopods discern colour when they have only one kind of light receptor in their eyes? And they must be able to discern differences in colour. Consider how they signal with colour and how they camouflage.

Research from 2016* puts forward that their uniquely shaped pupils act like prisms, scattering light into different wavelengths (chromatic aberration), rather than focussing the light into a beam onto the retina.  The hypothesis, tested with computer modelling, is that cephalopods can then focus the different wavelengths onto their retina separately by changing the distance between the lens and the retina, thereby separating the stimuli and discerning colour. Note that the sharpness of their vision is believed to be different for different wavelengths / colours.

Even with their eyes closed, octopuses can detect light with their skin. This is tied to their ability to camouflage with the photoreceptors in their skin responding to specific wavelengths of light (different wavelengths = different colours).

Note too that octopuses do not have eyelids. They have have a ring-shaped muscular fold of skin around the eye that closes in the way of an eyelid (especially when some annoying human is taking photos).

There, I feel much better now. Bring on the New Year.

Here’s to all the colour, marvellous mysteries, clear vision, and solid action ahead.

*Sources

Katz, I., Shomrat, T., & Nesher, N. (January 01, 2021). Feel the light: sight-independent negative phototactic response in octopus arms. The Journal of Experimental Biology, 224.

Stubbs, A. L., & Stubbs, C. W. (July 19, 2016). Spectral discrimination in color blind animals via chromatic aberration and pupil shape. Proceedings of the National Academy of Sciences of the United States of America, 113, 29, 8206-8211.

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, meet the Wrinkled Amphissa (Amphissa columbiana). They are also known as “Wrinkled Dove Snails”.


This species of marine snails is so fabulously wicked. A gland near their foot can secrete thick mucus allowing them to climb up and down to where they smell food and suspend themselves. See that strand above the two Wrinkled Amphissas in the photo?

At only up to 3 cm long, they can also deter MUCH bigger sea stars. Read on!

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.

Scavenging

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.

Where are they abseiling to? These marine snails are big-time scavengers and are very active, using their long siphon to smell out dead animals and algae.

“Characteristic searching posture of A. columbiana with the siphon extended and sweeping back and forth to test the waters (illustration by L.F. Braithwaite).”

It appears they can detect the chemicals of decay incredibly well and they also follow the mucus trails of others of their kind. Often a pile of them are scavenging together as you seen in the photos below.

Feeding on a dead Buffalo Sculpin ©Jackie Hildering.
Feeding on the arm of a dead Sunflower Star ©Jackie Hildering.
Feeding on the sorus (spore packet) of Bull Kelp ©Jackie Hildering.
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!
Wrinkled Amphissas and Oregon Tritons snacking on a dead Lingcod. Nothing is wasted in the wild. ©Jackie Hildering.
Feeding on a dead Northern Moonsnail ©Jackie Hildering.
Feeding on a dead Leafy Hornmouth ©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.”

Biting

They also have a wicked defence against sea stars where they insert their very long mouth part (the proboscis can be more than 2.5 times the lenght of the shell) 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 Wrinkled Amphissas.

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 above 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 are – octopuses!

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.

Invertebrates of the Salish Sea – Amphissa columbiana

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 resource “A 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: