MARINE INVERTEBRATES | The Marine Detective

Hurts My Brain – Salp Chain!

These extraordinary animals are not jellyfish. In fact, they are more closely related to you than they are to jellyfish.

These are salps. They are planktonic tunicates with an astounding lifecycle and whose importance includes cycling of nutrients and reducing carbon.

*Natasha Dickinson and aggregate form of Salpa aspera. Natasha was my dive buddy on the dives I reference here. We were diving with God’s Pocket in Browning Pass. Photo: Jackie Hildering.*

When diving this past April, we happened to be in a bloom of the salp species “Salpa aspera“.

It was truly mind-rupturingly, staggeringly astounding to be carried in the current with so many chains of clones snaking by (they are jet propeled). Yes, I had to make up a new adverb just for this experience!

The stomach is the dark, circular organ you see in each individual in the chain (aggregate).

We also saw an individual break from the chain and move independently! More on that below.

*Male Kelp Greenling nipping at Salp aspera. We also saw multiple rockfish species feed on them. Seastar species here is a Striped Sun Star. Photo: Jackie Hildering*

Which species of salp?

I did not know which species of salp was all around me. Thankfully, I was able to tap into expertise far greater than my own. Moira Galbraith, Zooplankton Taxonomist with the Institute of Ocean Sciences, very generously shared her knowledge when I sent her my photos, euphoric observations, and request for an ID.

Moira’s answer to my ID request:
“By the size of the stomach and placement (red/green ball), the shape of the ganglion (the c-shape you can see at opposite end from the stomach) and the short projections along where the individuals are attached to each other; I would say that this is Salpa aspera. These have been washing up on beaches off the west coast of Vancouver Island. . ..

Each individual takes in water through the front and channels it out the back. There are muscles bands along the body which create a pulse or pump. Food is taken from the incoming stream and diverted to the stomach. The water going out the back allows the animal to propel itself through the water. Chains work together making it look like a snake or an eel moving through the water.”

Importance?

Salps can grow and reproduce VERY quickly when conditions are right. They are one of the fastest growing multicellular animal on Earth.

Salps are also big zooplankton.

As a result of their size and number, a whole lot of water gets filtered and the poop that comes out is bigger than the plankton that got consumed. These big “fecal pellets” sink and transport nutrients.

If the fecal pellets make it to the bottom of the ocean, they could carry carbon away from where it will enter the atmosphere. Further, when salps die, their bodies also sink quickly and could thereby remove more carbon from entering the atmosphere.

Lifecycle:

The chains are the “aggregate” form of the salp lifecycle. They are all female clones.

A male individual fertilizes the aggregate.

The females break-off from the aggregate and release a single embryo. The solitary females then go on to develop testes, become males and fertilize the aggregates.

Whoa! Imagine how astoundingly it was for us to watch an individual break from the aggregate and then move independently. If I understand the lifecycle properly, this would have been a female with an embryo.

*Salp lifecycle. – alternation of generations where the asexually reproducing form makes the sexually reproducing form. Source: Henschke et al.*

*Salpa aspera aggregate and the individual in the video (on the bottom left). All the pink animals on the ocean bottom are Great Winged Sea Slugs and their egg masses!*

More information:

Madin et al., 2006:
“Development of such large populations is presumably made possible by the high rate and efficiency of filter feeding by salps, their rapid growth and their alternation of sexual and asexual reproduction. These characteristics permit a rapid population response by salps to favorable food availability, such as may result from seasonally high phytoplankton productivity in oceanic regions of water mass intrusions and mixing along fronts. In some locations, high population densities of salps can be produced in as little as a few weeks.”

Woods Hole Oceaonographic Institute:
“From their clear, blob-like appearance, you’d be forgiven for mistaking the salp for a jellyfish. But it turns out that these gelatinous zooplankton actually are more closely related to humans than to brainless jellyfish. Unlike the jellyfish, salps (and humans) boast complex nervous, circulatory and digestive systems, complete with a brain, heart, and intestines.

Salps use jet propulsion to efficiently glide through the ocean. They’re great at multitasking: while expanding and contracting their muscles to move, they’re also pumping phytoplankton-rich water through their feeding filters, taking in the nutrients they need to survive . . . .

When food is plentiful, they can quickly create more chains, and each salp can increase rapidly in size. This superpower makes them one of the fastest-growing multicellular animals on Earth. Like all good things, the salp bloom comes to an end when all their available food is consumed.

Found throughout the world ocean, salps play an essential role in the ocean’s biological pump. Because they feed on phytoplankton—which grow in the presence of sunlight and carbon dioxide—salp poop is extremely rich in carbon. When these fecal pellets (and dead salps) fall to the seafloor or are snapped up by other twilight zone creatures, it’s like putting carbon into a bank vault.

The carbon remains at the bottom of the ocean for years, if not centuries, helping regulate our climate. Scientists don’t yet have an accurate assessment of how changes in salp numbers and distribution could affect the ocean’s carbon cycle—and impact climate change—but it’s clear that these critters play an important role.”

New York Times article about the research of Sutherland and Welhs (2017).

[Note that this research was on two different species of salp.]

“Meet the salp. It typically lives in deep waters, where its barrel-shaped body glides around the ocean by jet propulsion, sucking in water from a siphon on one end and spitting it back though another. It swims alone for part of its life. But it spends the rest of it with other salps, linked together in chains arranged as wheels, lines or other architectural designs . . .

Over years of watching them swim in chains, she [Dr. Sutherland] made a surprising discovery. They synchronize their strokes when threatened by predators or strong waves and currents. But while linked together in day-to-day life, each salp in the chain swims at its own asynchronous and uncoordinated pace. Counterintuitively, this helps salps that form linear chains make long nightly journeys more efficiently.

The life story of the sea salp is peculiar. Each one starts life as a female, then switches to male . . .

Making chains is part of their life cycle, and if these chains break, they don’t link back together. Each salp lives only a few days or a month in two stages: solitary, and in a colonial chain. A solitary salp gives rise to a colony of genetically identical salps asexually. The salps are connected in a chain that starts as a coil around the solitary salp’s gut. It grows over time and eventually breaks free, the beginning of the colony phase. Each individual within the chain will reproduce sexually. Through spawning, a male’s sperm reaches a female’s egg, forming a baby solitary salp that eventually swims out of its parent. “That solitary will make a chain and so on,” said Dr. Sutherland. It’s a chicken-or-the-egg kind of situation.

Perhaps to enhance a salp’s reproductive success, many salps migrate vertically, from the deep sea toward its top at night and back down during the day. At the surface, they can congregate with a greater chance that the sperm of one hits an egg of the same species.

And salps in linear chains are particularly skilled at this migration, traveling thousands of feet each night, at speeds around 10 body-lengths a second. “That’s like running a marathon every day,” said Dr. Sutherland.

You might think that fast synchronized, coordinated swimming strokes would be the way to make that happen. But each salp in the chain pumps to the rhythm of its own built-in pacemaker.

The resulting swim isn’t as fast, but it’s smooth and sustainable, with less interference from the wakes made by individuals. It’s like the difference between a Porsche and a Prius, said Dr. Sutherland. A Porsche can accelerate quickly to top speeds, but a Prius is more fuel-efficient.”

Poorly lit photo but gives you a sense of how long the aggregate / chain can be. I would estimate this one to be nearly 4 metres long. ©Jackie Hildering

Sources:
Henschke N, Everett JD, Richardson AJ, Suthers IM. Rethinking the Role of Salps in the Ocean. Trends Ecol Evol. 2016 Sep;31(9):720-733. doi: 10.1016/j.tree.2016.06.007. Epub 2016 Jul 18. PMID: 27444105.

L.P. Madin, P. Kremer, P.H. Wiebe, J.E. Purcell, E.H. Horgan, D.A. Nemazie (2006), Periodic swarms of the salp Salpa aspera in the Slope Water off the NE United States: Biovolume, vertical migration, grazing, and vertical flux, Deep Sea Research Part I: Oceanographic Research Papers 53 (5), 804-819

Nereus Program Our jelly-like relatives: Common misconceptions about salps

New York Times (2017) – It’s Better to Swim Alone, Yet Together, if You’re a Salp

Sutherland Kelly R. and Weihs Daniel (2017) Hydrodynamic advantages of swimming by salp chains. R. Soc. Interface.142017029820170298

Wood’s Hole Oceanographic Institute – CREATURE FEATURE – Salp

*Salpa aspera aggregate and another dive buddy, Linnea Flostrand. ©Jackie Hildering.*

Slime Star!

Did you know about the species of sea star in our waters that releases slime to deter predators?

Slime stars are so wickedly adapted! Their distinctive puffy bodies have led to them also being known as Cushion Stars.

They release a LOT of thick, transparent goo from their upper surface when disturbed.

Disturbance constitutes rough handling, temperature shock or when other sea star species try to eat them. Sunflower Stars and Morning Sun Stars are known to trigger the slime production and get a mouthful of goo. The mucus is reported to be toxic to other invertebrates if they are immersed in it for 24 hours.

How much mucus do Slime Stars produce?
See the Hakai Institute’s video below.

What is also so unique about Slime Stars is that they “exhale” water through that big pore in their upper surface every few minutes (the osculum). The full “exhalation” of the water takes about 5 seconds. You can see in the photos and video below how wide the hole opens. Water enters the sea star on the underside (through ambulacral grooves).

Video from Invertebrates of the Salish Sea.

*The same Slime Star as in the previous photo.*

The tips of the arms / rays of Slime Stars are also distinctive. See how they curl upward? That is believed to be an adaptation to hold the mucus on the upper surface of the sea star.

*See how the tips of the rays are curled upward?*

As a result of genetic research, it has been put forward that the individuals with dark markings may be a distinct species from the solid-coloured ones. Currently, they are all classified as Pteraster tesselatus.

– Maximum size: 24 cm across.
– Known range: Bering Sea to Washington State; from 6 to 436 meters.
– Diet: Sponges, tunicates, and bivalves such as the False Jingle.

Sources:

Invertebrates of the Salish Sea – Pteraster tesselatus
Neil McDaniel – Sea Stars of the Pacific Northwest – Slime Star
A Snail’s Odyssey – Sea stars – Defences – Mucus

My photos in this blog are all from near northeastern Vancouver Island in the Territory of the Kwakwa̱ka̱’wakw (the Kwak̕wala-speaking Peoples) ©Jackie Hildering.

*Injured Slime Star. Appears to have been bitten by a crab.*

Zyzzyzus rubusidaeus

One of the services I like to provide here on The Marine Detective, is to share words you can try to randomly drop into conversations and annoy your friends. You’re welcome. It’s a task I take very seriously.

Yes, there really is an animal with the scientific name Zyzzyzus rubusidaeus and to me, they look like they have been designed by Dr. Seuss himself. Their common name is the Raspberry Hydroid and they have beautiful predators too.

The common name for Zyzzyzus rubusidaeus is the Raspberry Hydroid. They were only described as a new species in 2013 by northern Vancouver Island’s own Anita Brinckmann-Voss who lived in Sointula. The research paper is at this link.

Their specific nudibranch prey are Pomegranate Aeolids. To my knowledge, the only documentations for both species, to date, are near Telegraph Cove (Weynton Pass) and Quadra Island (Discovery Passage). I can certainly attest to how fortunate we are to see them so predictably near Telegraph Cove.

*What you see here, in addition to Raspberry Hydroids and a Pomegranate Aeolid nudibranch, are Mushroom Compound Tunicates, and a feeding Giant Acorn Barnacle.*

See below for more information about both species. Oh, and if you ever are able to use the word “Zyzzyzus” in a word game because of this post, I expect a thank you! 😉

Descriptor for the above photo:

Trifecta!

(1) Nudibranch species the Pomegranate Aeolid (Cuthonella punicea to 2.5 cm).

(2)Their only known prey, the stinging celled animals Raspberry Hydroids (Zyzzyzus rubusidaeus to 5 cm tall).

(3) The nudibranchs’ egg masses / strings. As is the way with sea slugs, they most often lay their eggs on their prey. Talk about adding insult to injury. I eat you and I lay my eggs on you so there will be more of my kind to prey on your kind.

*More Pomegranate Aeolids feeding on Raspberry Hydroids. This is a female colony. The round structures are female gonophores which may contain embryos.*

More about hydroids:

Almost all hydroid species are colonial. They are carnivores. Hydroids are related to jellies, anemones, and corals (phylum Cnidarian).

The reproduction of hydroids is remarkable. Colonies are male or female. They start by reproducing asexually by budding off hydromedusa – tiny free-swimming, jellyfish-like versions of themselves. These produce either eggs or sperm. Fertilization of the eggs leads to larvae that may settle on the ocean bottom and form colonies.

Hydroids catch drifting prey with their polyps aided by their nematocysts (stinging cells). None of the hydroid species off our coast deliver a sting that we humans can feel (no matter how sensitive you are 😉).

The food gets distributed throughout their single-sex colony.

And who loves to eat species of hydroids? Nudibranchs! Specifically, the aeolid kinds of nudibranchs – they have those bushy structures on their backs (cerata). Many of these nudibranch species not only rely on the hydroids for nutrition but also make use of their prey’s stinging cells! The nematocysts get incorporated into the ends of the cerata.

Sources:
Brinckmann-Voss, A., & Calder, D. R. 2013. Zyzzyzus rubusidaeus (Cnidaria, Hydrozoa, Tubulariidae), a new species of anthoathecate hydroid from the coast of British Columbia, Canada. Zootaxa 3666: 389-397

Nakwakto Goose-neck Barnacles

Please tell me these made you gasp?

These are barnacles that live in only a very few places on the planet. The most are at Nakwakto Rapids, north of Port Hardy. The red is hemoglobin!

I think these are one of the most achingly and extraordinarily beautiful animals I have ever seen.

They are Nakwakto Barnacles. They need really strong current and that was very clear during the dive where I photographed these, even on a small tidal exchange). The dive site was Turret Rock, also known as Tremble Island because of the appearance that the island shakes in the tidal exchange (apparently up 39 kilometers per hour during its largest tidal exchanges).

*Nakwakto Goose-neck Barnacles with Split Kelp wafting behind.*

The next photo shows you the SAME species but in shallow water where you can’t see the hemoglobin because, near the surface, the gooseneck barnacles need a protective black pigment against sun exposure. How’s that as a metaphor for how your environment influences your beauty?

These barnacles are perceived to be a variant of Gooseneck Barnacles with the same species name, which is Pollicipes polymerus.

The barnacles’ stalk can be 15 cm long and body to 4.5 cm long.

*An attempt to show you the density of this species in this extraordinarily high current area.*

From Hanby and Lamb’s Marine Life of the Pacific Northwest: ” . . . the spectacular formations of the Nakwakto goose-neck barnacle, a large and colourful variation of the goose-neck barnacle – found in Nakwakto Rapids, Slingsby Channel, c. BC. The glorious red colour is actually the hemoglobin in the barnacle’s blood. The blood is obvious in subtidal specimens like these, which do not have the black pigment that protects the sun-exposed populations inhabiting shallow or intertidal zones . . . this unique and isolated population must be preserved via a No-Take Marine Protected Area.“

From Rubidge et al 2020; “A unique subtidal variety of the Gooseneck Barnacle, Pollicipes polymerus, forms large aggregations at Nakwakto Rapids (Lamb and Hanby 2005). The “Nakwakto variety” of P. polymerus, is bright red as the hemoglobin in the barnacles’ blood is visible. Subtidal populations do not need the black pigment found in the sun-exposed intertidal populations (Lamb and Hanby 2005). The red “Nakwakto variety” of P. polymerus has been recently reported in other subtidal areas including a sea cave on Calvert Island on the central coast and Race Rocks near Victoria. Because of its slow recovery rate after perturbations and its ecological role as a habitat-forming species, P. polymerus was identified as an Ecologically Significant Species and conservation priority for the Marine Protected Area network planning process in the Northern Shelf Bioregion (DFO 2017).“

Photos: September 17 and 18, 2022, near the Nakwakto Rapids in Gwa’sala-‘Nakwaxda’xw Territory ©Jackie Hildering.

Sources:

Rubidge, E., Jeffery, S., Gregr, E.J., Gale, K.S.P., and Frid, A. 2020. Assessment of nearshore
features in the Northern Shelf Bioregion against criteria for determining Ecologically and
Biologically Significant Areas (EBSAs). DFO Can. Sci. Advis. Sec. Res. Doc. 2020/023. vii +
63 p

Found! Cryptic Nudibranch

I finally observed some of the most cryptic nudibranchs on our coast!

The Cryptic Nudibranchs you see here are only about 1 cm long and look at how astoundingly evolved they are! They are virtually invisible on the Kelp-encrusting Bryozoan which is growing on Bull Kelp at this time of year. This species of nudibranch is also known as Steinberg’s corambe (Corambe stinbergae to 1.7 cm).

You can see in the photos here that we found some of the nudibranchs mating and there were many of their egg ribbons (each of those coils has a lot of eggs that result from both parents becoming inseminated and laying eggs).

You can also see where they have been feeding on the bryozoans (colonies of animals).

I have looked for them for years knowing their range is from Alaska to Baja California, Mexico.

*Mating: Right-side-to-right-side attached via the gonophores. Both hermaphrodite parents lay eggs.*

What made the difference in now being able to find them:

(1) Getting the clue from Robin Agarwal to look at the kelp fronds that were REALLY tattered with the Kelp-encrusting Bryozoan colonies .

(2) Having a skilled dive buddy willing to join me in burying our heads in old, tattered kelp in the surge for 30 minutes instead of looking at all the big, colourful life at this dive site. Thank you Janice Crook!

(3) Once we knew what the egg ribbons looked like (those s-shaped little masses), we had a really good clue and knew better where to look even more closely for the nudibranchs.

Now on to finding the SECOND really cryptic nudibranch species that feeds on Kelp Encrusting Bryozoans – Corambe pacifica to 1.5 cm long and whose egg masses are tiny, flat coils.

For more photos and my previous blog on what Kelp-encrusting Bryozoans look like, please see my other blog “Kelp Lace? Bryozoans”.

Photos: September 19, 2022, Browning Pass ©Jackie Hildering, The Marine Detective.

Happy dive buddies
– Janice Crook and yours truly.

Kelp Lace? Bryozoans.

And so it begins.
It’s the time of year when the annual kelps like Bull Kelp begin to break down. It’s then that Kelp-encrusting Bryozoans really get a chance to colonize the kelp as you see in these photos.

Every little box is an individual animal. It’s a “zooid”. The oldest member is in the middle and the others all originated from that one by asexual reproduction.

The zooids filter feed on plankton with the tentacles you see in this wonderful video by friend Karen Johnson. These crowns of tentacles are known as lophophores.

“Kelp-encrusting Bryozoan” (Membranipora membranacea) is also known as “Kelp Lace Bryozoan”. It’s no mystery how either common name was inspired. Each circular colony is approximately 20 cm wide.

If you are lucky enough to live near the Ocean, look at the kelp that washes ashore for these colonies. The colonies in these photographs where on Split Kelp (Laminaria setchellii) and Bull Kelp (Nerocystis luetkeana).

What on earth is a “bryozoan”?

From Beachkeepers: “Bryozoans are colonial animals that arrange themselves in circular (radial) fashion, often with the oldest (and first to settle) individual in the middle. . . . The ‘box’ of the zooid is made of either a tough protein (like what you would find in crab shells) called chitin, or what you would find in coral reefs, calcium carbonate. This body box has an opening where the bryozoans extend their feeding apparatus (that looks a lot like a sea anemone) called a lophophore. Yes, they have predators! [Some species of] nudibranch will eat them, though they can reproduce asexually to form the colony back to size after a nudibranch has been grazing on them. Sometimes, when they grow back, they’ll even grow chitonous spines on their body walls to discourage the nudibranchs from coming back. These spines usually form on the individuals on the outside edge of the colony.”

*Adalaria nudibranchs feeding on the bryozoan.*

*Blue Turban snail feeding on Kelp-encrusting bryozoan.*

*Opalescent Nudibranch near a colony of Kelp-encrusting Bryozoan.*

Detail about this bryozoan species – Kelp-encrusting Bryozoan.
From Invertebrates of the Salish Sea: “Bryozoans start from a single individual zooid (an ancestrula) which repeatedly reproduces asexually to form a colony. In this species, the oldest individual is in the middle. Colonies of this species usually begin to be noticeable in late spring and grow through summer into fall. By fall they may form extensive crusts on the kelp and many colonies have merged with one another. In many bryozoans there are various types of zooids but in this species there is only one type of zooid which serves for feeding, for reproduction, and for defense. The colony appears to be a simultaneous hermaphrodite, or male zooids may develop first. They do not brood their young. Eggs are fertilized then released, and quickly develop into cyphonautes larvae which may feed and develop as plankton for several months. The larvae settle when they encounter kelp such as Laminaria or water with an excess of potassium ions. The small white nudibranch Doridella steinbergae [reclassified to Corambe steinbergae] may be found living and feeding on these colonies but it blends in so well it is difficult to see . . .”
Note there is a second similar looking cryptic nudibranch that can found on these bryozoans and that is Corambe pacifica. Corambe pacifica has a notch at the back. Corambe steinbergae does not.
I have never managed to find these cryptic nudibranchs. Grateful to Karolle Wall and Robin Agarwal for their photos below.

What happens to the kelp?

It is the natural cycle of kelp species like Bull Kelp, that at this time of the year, the large version (the sporophyte) begins to break down. Spore packets drop to the bottom of the Ocean which create a different version of the kelp. It’s Alternation of Generations and here is my blog about that wonder. Other kelp species like Giant Kelp are not annuals. They remain year round.

*Spore packets (in the centre of the kelp fronds).*

All photos (other than those by Karolle Wall and Robin Agarwal) were taken in early August near northeast Vancouver Island in Kwakwaka’wakw Territory ©Jackie Hildering.

Additional information:

Hageman, Steven J., et al. “Bryozoan Growth Habits: Classification and Analysis.” Journal of Paleontology, vol. 72, no. 3, 1998, pp. 418–36. JSTOR

Washington State Department of Ecology, Moss animals: Animals in plant disguises!

Note: Some report that this species of bryozoan is an invasive in the Atlantic. However, “recent genetic studies indicate that this species is a complex of a number of long-separated clades. The only verified invasion is its introduction from the Northeast Atlantic to the Northwest Atlantic” (Source: Nemesis).

Whorling Wizardry

Here’s a big dose of wonder for you.

It’s the time of year when female Oregon Tritons are laying their eggs. These are BIG, predatory marine snails at up to 15 cm long.

Look at how many fertilized eggs are in each “capsule” and marvel at the shape of the egg mass. These capsules are referenced as “sea corn” for this species. It takes each female about 2 weeks to lay her eggs in this wondrously shaped clutch. A friend referenced the shape of the egg mass as being reminiscent of Van Gogh’s “Starry Night”. Agreed!

See the “blank” egg capsules? They have likely been preyed upon e.g. by shrimp, hermit crabs or other snail species. You can even see hermit crabs and snails in these images feeding on the eggs. Some hermit crabs are even sitting on females as they lay eggs. Oh the cheek!

*See the hermit crabs and “blank” egg capsules?*

I could not resist providing a closeup on this Whiteeknee Hermit from the previous photo.
Look at those eyes!

*Closeup on a Blue Turban snail snacking on eggs (from previous photo).*

Almost every time I see Oregon Tritons lay eggs, they are doing so as a group. Reportedly, up to 30 individuals have been found laying eggs together.

Why are there so many eggs? Because chances of survival are so low when there is no parental care (other than the architectural marvel of the egg case) and the young hatch into the soup of the Ocean. Planktonic larvae hatch out of the eggs at about 2 weeks of age.  With it taking 2 weeks for the young to hatch, and 2 weeks for Mom to lay the whole mass, the first capsules could be hatching by the time she is finishing her work. I learned from aquarist Casey Cook from her microscopic observations at the Aquarium of the Pacific that, “By hatch time there are significantly less in the egg [capsules] than at the beginning of the lay. We presume the babies eat each other to gain nutrients for creating their first shell layers.”  

One study found that, in an aquarium, the larval stage for this species was up to 4.6 years and they only began metamorphosis into their adult form when something was available for them to settle on e.g. rocks (Strathmann and Strathmann, 2007). Further “time from metamorphosis to first reproduction was 3.3 years” (in these conditions in the aquarium).

The scientific name for Oregon Tritons is Fusitriton oregonensis. That’s a whole lot of Oregon in their name and the species is the official seashell of Oregon state (there’s trivia for you). However the range for this species is well beyond Oregon. They are found from northern Alaska to northern Mexico, and Japan. They are common around northeast Vancouver Island. Depth range is reported to be from the intertidal to 180 m. In my experience they are rarely in the intertidal however.

They are also known as the Hairy Triton. “Hairy” for the bristly “periostracum” you see atop the shells which appears to stop attachment of marine organisms. Some loose this bristly covering and, resultantly, can have a lot of settlement and growth on their shells.

The brown structure you see at the opening of the shell is the operculum. This is hard and made of keratin and serves as the door to close the shell. More about that in my “Shut the Door!” blog at this link.

Predatory? Yes! They are among the marine snail species that drill holes into prey, sedate, and slurp. From Invertebrates of the Salish Sea: “Feeds on ascidians, urchins, bivalves, sea stars, brittle stars, chitons, abalones, and polychaetes [worm species] . . . It produces sulfuric acid in its salivary glands, which may help in boring through shells. A gland in the proboscis secretes an anaesthetic used for subduing prey. It feeds with biting jaws as well as a radula . . . Humans should not eat this snail because it carries a pathogen in its salivary glands which can be fatal to humans.”

I have also seen this species scavenge on dead crabs, anemones and fish and eat Lingcod eggs.

*Oregon Tritons scavenging on the head of a Lingcod.*

*Oregon Tritons mating. I hope you appreciate the mood lighting.*

*Oh look! It’s a Scalyhead Sculpin (indicated with arrow).*

Octopuses Have Arms

Big questions often come from little people and there are so many times that I have been asked by children why I reference the limbs of an octopus as “arms” and not “tentacles”.

Here’s why:
Arms have suckers down the full length of the appendage. Tentacles only have suckers near the tip. Thereby, all eight octopus appendages are arms while squid have two tentacles and eight arms. Further, the purpose of tentacles is generally limited to feeding where arms have more functions. Octopuses use their limbs for feeding, locomotion, reproduction (if male*), defence, etc!

Oh and why are they called “arms” vs. “legs”? Because octopuses’ appendages have more purposes than just locomotion.

*Octopus walking on her arms (and you thought YOU were special 😁). How to know this is a female octopus? See below for the link to my blog* on octopus sex.*

There are scientists who have put forward that some octopus species use two of the limbs mostly for locomotion whereby they would have two “legs” and six “arms” but let’s avoid that debate!

While we are on the topic of semantics and cephalopods, and anticipating that there will be those who question my use of the plural form of “octopus”, please note the origin of the word octopus is Greek, not Latin. Thereby “octopuses” or “octopods” is truly more correct than “octopi”. From a strict linguistic perspective, the most correct is “octopods” but I choose not to use that. I think if I were to say “octopods” it would distract what I am trying to communicate that is more important that grammar. I might also come across as pretentious and have fewer human friends 🐙.

There, don’t you feel much better armed to speak for our awe-inspiring eight-legged neighbours? Or, are you up in arms?

*Related blog: Giant Pacific Octopuses – How Do They Mate?

Worms That Bite Anemones?!

Okay, this is a true mystery.

I have relayed my observations to marine worm researchers but want to share with you too. It’s just too fascinating not to do so. These finds emphasize yet again how little we know even about marine species that are just below the surface. I also hope that by sharing my observations here, it may lead to other divers being on the lookout for these interactions and potentially adding to the knowledge about interactions between necklace-worms and anemones.

*Necklace-worm species #1 and Proliferating Anemone – January 1st, 2008.*

*Necklace-worm species #2 and Short Plumose Anemones – March 6, 2022.*

My observations involve what I believe are two species of necklace-worm. Each is interacting with a different species of anemone. In both cases, the species of necklace-worm is unconfirmed. The polychaete* researchers I have been in contact with have asked for samples of the worms to allow for microscopic examination and potential DNA analysis.

*Polychaetes are the “many-bristled” worms. They are worms that have a pair of paddle-like appendages / bristles on each segment. Most species of worm in this class are found in the ocean or in brackish water and there are about 15,000 known species globally. Polychaetes “are ubiquitous in the ocean, burrowing and hunting in the sand, crawling on algal covered rocks, living in self-made tubes, or swimming in the water” (Encyclopedia of Biodiversity, 2013).

Note that observations and photos here are from the Pearse Islands and Plumper Islands on northeast Vancouver Island in the territory of the Kwakwaka’wakw in depths less than 17 metres / 50 feet.

Necklace-Worm Species #1 and Proliferating Anemones:
I have written about this previously but include the observations here again so that the information about these necklace-worm / anemone interactions is bundled in one place. It involves a species of necklace worm appearing to bite into Proliferating Anemones (Epiactis prolifera to 8 cm wide).

My first observation of this interaction goes back all the way to 2008 when I documented the following thanks to the keen eye of my dive buddy Natasha Dickinson.

*Both photos: Necklace-worm species #1 appears to be biting into a Proliferating Anemone – January 1st, 2008.*

I do not know if the necklace-worm dislodged the anemone of if the anemone let go in an attempt to get away. We came upon this scene when the anemone was already upside down.

I have only noted this interaction twice since then. See photos below.

*Necklace-worm species #1 and Proliferating Anemone – February 15, 2015. Note the “casings” the worms are in on the left.*

*Necklace-worm species #1 on the right and Proliferating Anemones – February 22, 2020. [Yes, on the left, those are babies of multiple ages hanging onto their mother. More about that at this link.*]

For those who have Lamb and Hanby’s Marine Life of the Pacific Northwest, you may note that this species of necklace-worm looks like AN22 which is referenced as a “mystery necklace-worm”. But again, collection of a sample would be needed to confirm species ID.

Necklace-Worm Species #2 and Short Plumose Anemones:

On February 12, 2022 I saw THIS.

*Necklace-worm species #2, Short Plumose Anemones AND the spaces where these anemones used to be. Many of these anemones are retracted. Photo February 12, 2022.*

There are necklace-worms in those slime tubes! Where you see the circles is where other Short Plumose Anemones once were (Metridium senile to 10 cm tall and 4 cm across).

*Close-up showing the necklace-worms. Photo February 12, 2022.*

Were they always at this site? I have done a quick review of past photos and see a few of them in photos back to 2013. Variables in why I may not have noticed them before are that: (1) they were much more apparent as a result of the dislodged anemones; (2) there may be more of them now; and (3) we usually don’t focus on the spot where the concentration of these worms were (we usually dive deeper).

*Here’s another photo from that dive to give a better sense of the size of the worms. That Blood Star is about 15 cm long. Photo February 12, 2022.*

So TODAY’S mission was to return to this dive site and focus on the interaction between this species of necklace-worm and Short Plumose Anemones. How abundant are they? Are they biting the anemones?Are the worms anywhere other than around Short Plumose Anemones? Are the anemones using their acontia as a defense against the worms? Acontia are defensive strands filled with stinging cells (nematocysts) that are ejected when an anemone is irritated / threatened / stressed. The acontia can extend far beyond the anemone, providing longer distance defense than the stinging cells in an anemone’s tentacles.

Dive buddy Natasha Dickinson today. This is the exact same spot as what you see in the images from February 12th above. I contrast the two photos at the very end of this blog so you can see how things have changed after 22 days. Of course I do not know how much the anemones would move around in the absence of the worms.

To answer those questions:
– I found the slime tubes almost everywhere there were Short Plumose Anemones at this site. I did not find them anywhere else i.e. this species of necklace-worm’s slime tubes were only around Short Plumose Anemones.
– I only found a few Short Plumose Anemones using their acontia but it seems more likely that they were being used against other anemones. I cannot know if the anemones dislodge themselves as a defense. There were only a few places where there were the circles of slime tubes where an anemone had once been. There were far more places where the slime tubes were in amongst Short Plumose Anemones.
– YES I do believe this species of necklace-worm is biting into the Short Plumose Anemones. See below for abundant photos from today.

*Some Short Plumose Anemones using their acontia. See those little white strands?*

I will of course provide updates as I learn more via the researchers and other divers / underwater photographers. As always, I hope it is a source of wonder for you to learn more about these species, their adaptations and interactions, AND how much we humans still have to learn about the natural world around us. 🙂

All photos below are from March 6, 2022.

*Taking a bite? Also looks like this anemone is about to undergo “pedal laceration” to reproduce asexually.*

*Here too it looks like some of the anemones are in the process of pedal laceration = form of asexual reproduction.*

Below, you can contrast the same spot after 22 days. There has been a lot of change but again, I do not know how much the anemones would move around and/or dislodge in the absence of the worms. Oh no, is this now going to be my life? In addition to trying to document individual Humpback Wales and Tiger Rockfish, now I am going to try to document individual Short Plumose Anemones?! Probably.

My additional photos below are from March 19 2023, providing further documentation of Necklace Worm species #2 targeting the Short Plumose Anemones and possibly stimulating pedal laceration and acontial defense.

It’s a Really Good Time to Be . . .

Yesterday, we found two Sunflower Stars!

See the juvenile here to the right of my buddy Natasha? There, right beside the mating Yellow-Rimmed Nudibranchs. This Sunflower Star was in just 5 metres of water.

Today’s two Sunflower Stars are the first I have seen in twelve hours underwater over the last three months and believe me, I have been looking. I only saw one before that. They are such a rarity now. Will these two survive? I have seen waves of juveniles before and then they disappear. Their plight appears to be linked to climate change.

Hope? With action . . . yes, there is shining hope.

Without action . . . no.

Please hang in there. Please read on.

I have been struggling too, looking for escape / reprieve from global realities as another “atmospheric river” is forecast to fall on parts of our province. It is so tempting to want to hide especially if we see the problems we are facing as disparate. They are not.

I have had to remind myself of the common solutions so that I see a way forward that is not guided by the faintness of blind hope; paralyzed by fear and overwhelm; and / or obfuscated by the din of values and voices that serve the few for a brief time.

Common solutions include: to know, live and share the GAINS that come from using LESS (fossil fuels, dangerous chemicals, disposables, less consumerism generally); to speak for truth and science and to have compassion for those who cannot; to exercise our power as voters and consumers to serve future generations; and to care and act on the knowledge of connection to others – across time, cultures, distance, and species.

In short, it’s a really good time to be a good human.

I had to dig for these words for myself. As always, may they serve you too.

Photos: November 21 in Kwakwaka’wakw Territory near Port Hardy at a site where I have been monitoring sea star since 2013, ©Jackie Hildering.

*The same juvenile Sunflower Star a few minutes earlier. Notice the fish? There’s a Painted Greenling on the left and a Blackeye Goby on the right.*

For those who are not yet aware, I include the reality of Sea Star Wasting Disease (SSWD) below. A link to a summary of the research and where to report sightings is in my blog at this link.

*The other Sunflower Star we saw yesterday.*

Since 2013, more than 20 species of sea star have been impacted by SSWD from Mexico to Alaska. There is local variation in intensity of the disease and which species are impacted. It is one of the largest wildlife die-off events in recorded history. Sea stars contort, have lesions, shed arms, and become piles of decay.

Currently, some species of sea star appear to have recovered while others remain very heavily impacted. Sunflower Stars (Pycnopodia helianthoides) have been devastated and were added to the International Union for Conservation of Nature (IUCN) list as Critically Endangered. There are current efforts to have Sunflower Stars assessed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) with hopes that they receive protection under Canada’s Species at Risk Act.

There is NOT scientific consensus about the cause. Current hypotheses focus on (i) a virus and (ii) low oxygen at the surface of the sea star’s skin maintained due to bacteria. What is consistent in is that changing environmental conditions appear to allow the pathogen (be it bacteria or viruses) to have a greater impact.

The best current source for a summary of the research is Hamilton et al (August, 2021). From that source: ” . . . outbreak severity may stem from an interaction between disease severity and warmer waters” and “Though we lack a mechanistic understanding of whether temperature or climate change triggered the SSWD outbreak, this study adds to existing evidence that the speed and severity of SSWD are greater in warmer waters”.

What I believe to be the reality off the coast of British Columbia is that there are refuges of Sunflower Stars at depth where it is colder. They spawn with some young then settling in the shallows where they may succumb to the pathogen if stressed by warmer water.

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

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