Under the donut shop

I took a short detour this afternoon, downtown, looping through a small dock area, peering between floats and under ramps.

Where the sun managed to reach, and where the waves stopped dancing, I caught a few glimpses of a vibrant community.

Plumose anemone, Metridium senile.

Back in the shade, there's a glassy bulb, possibly a tunicate. And a branch that may be a hydroid.

A small lion's mane jelly, Cyanea capillata

This was a youngster, only about a hands'-breadth across, and swimming actively, folding itself up, then opening again rhythmically.

Spreading out, heading under the wharf. With a green sea urchin.

On the bottom of a float (blue) and the pipes under a cabin.

So many critters! So many colours and shapes! I can't identify most of them, but there's a beautiful purplish feather-duster worm, limpets, orange and pink sponges, another plumose anemone, and something bright orange that may be the lips of a scallop.

And everywhere, there were tiny fish, breaking the surface so that it looked as if it were raining.

With the reflection of a donut shop.

Present, but too dark or too blurred by waves, hundreds of green sea urchins, mussels and barnacles, many orange starfish, a kelp crab and another two, too well hidden to identify, a fair number of chitons. And a kid fishing for shrimp. Who scared them all away.

Oh, and a big seal. Photos tomorrow.

~~~~~~~~~~~~~~~~~

Tomé un desvío corto esta tarde. Pasando por el centro, di una vuelta por un pequeño muelle, buscando entre los flotadores y debajo de las rampas. Donde alcanzaba la luz del sol, y donde las olas dejaban de bailar, llegué a ver señas de una comunidad vibrante.

Fotos:

1.  Una anémona plumosa, Metridium senile. En la sombra hay algo que parece un foco; posiblemente sea un tunicado. Y lo que parece una rama de árbol puede ser un hidroide.

2. Una medusa melena de león, Cyanaea capillata. Muy chica aun; apenas medía unos 10 cm. Iba nadando, estirándose y encogiéndose repetidamente.

3. Aquí está estirada. Con un erizo de mar verde.

4. Debajo de un flotador (azul) y en la tubería debajo de una cabaña. ¡Tantas criaturas! ¡Y de tantos colores y formas! No puedo identificar la mayor parte de ellas, pero se ve un gusano plumero color mora, lapas, esponjas anaranjadas y color de rosa, otra anémona plumosa, y algo anaranjado brillante que posiblemente sean los labios de una vieira.

5. Y dondequiera había un banco de pececitos, tocando la superficie del agua hasta que parecía que estaba lloviendo. Aquí están unos con los reflejos de una tienda de donas.

También hubo, pero escondidos en lo oscuro, o borrosos bajo las olas, cientos de erizos de mar verdes, mejillones y bálanos, muchas estrellas de mar anaranjadas, un cangrejo "kelp" y otros dos, sin poderlos identificar por estar bien escondidas, y bastantes quitones. Y un muchacho que pescaba camarones. Los cuales se habían hecho escasos.

Y también una foca grande. Mañana subo las fotos.

Dancing jester

Nothing is ever as simple as it seems. Especially underwater. Everything is layered; things grow on shells, on seaweed, on rocks; other plants and animals grow on those, and are home, again, to another community of something else. And everything eats. Hydroids eat plankton; nudibranchs and hermit crabs eat hydroids; crabs eat hermits when they can catch them; gulls eat crabs. So do we, if they're big enough.

On one of the blades of the skinny eelgrass I brought home the other day, I noticed a fuzzy barnacle. And the fuzz, looking at it with a hand lens, was not the expected diatoms or algae.

Side view of the blade of eelgrass. The barnacle is about 3 mm high.

These look like some type of hydroid; there's a stalk, a polyp surrounded by tentacles, these ones with knobs on the tips. But I can't find them in any of the books or web pages I've searched, probably because they are too small to attract attention.

Our common Obelia hydroids are branched.

Small Obelia, on another blade of the same plant. The eelgrass blade is 4 mm. wide.

But the new ones are clubs with at the most two polyps at the top. And they're noticeably orange, rather than semi-transparent like the Obelias.

But wait a minute! Looking at that first photo again, what is that thing that looks like a little man in a jester's hat? That's no hydroid!

I watched for a while, and the jester began to dance.

See him there, on the centre left side of the eelgrass?

It's a Caprellid, a skeleton shrimp. I never expected to see one so small. But nothing else dances like they do.

Standing upright again, waving antennae and big pincers (the jesters hat).

I found three more skeleton shrimp, all about the same size, along the blade of eelgrass. Standing upright, with the pincers raised, they mimic the hydroids, possibly as protection from predators that will avoid the stinging tentacles of a hydroid, and otherwise would find a caprellid quite tasty.

Most species are predators that sit and wait like a praying mantis, with their gnathopods ready to snatch any smaller invertebrates which come along. They accentuate their adaptive form and colouration by assuming an angular pose, resembling that of the fronds among which they live. They remain motionless for long periods of time while waiting to ambush their prey, often protozoa or small worms. (From Wikipedia, Caprellidae)

Wikipedia adds that they are eaten, in turn, by anemones, nudibranchs, and fish. I think I would add hermit crabs to the list. The colonies of hydroids and skeleton shrimp lasted only a night, with a dozen hermits busy cleaning the eelgrass. All that was left in the morning was the barnacle.

....

And there's more! Empty doughnuts tomorrow.

Life must cycle

Sea anemones reproduce in a variety of ways: by cloning, (splitting or tearing off a part of the parent's body, which then continues to grow as an adult); asexually by budding: or sexually, producing free-swimming planulae, which find a spot and settle to grow into the adult stage.

Hydroid bud. Released medusas will eventually reproduce sexually. Unlike these, the anemones' buds grow directly into adults.

Clones can be quite large; up to half the parent's body, but the buds and larvae are microscopic. Even the infant anemones, already settled, may be only a couple of millimetres across the base.

Like the ones I found in the clamshell:

One of several patches, on this and a second clamshell. What species? Time will tell.

The orange-striped green anemones outside of their home territory, reproduce by splitting. "At home," they also release sperm and eggs. Whether they consider my tank a home away from home, I don't know.

Orange-striped green anemone. Their colours and shapes are variable, even in the same individual at times.

Are these orange-striped? Probably. See the two at bottom left. The stripes are green.

These little anemones are appearing in large numbers all around the tank. They are obviously not produced by splitting; no mature anemone has been racing all around, dropping bits of himself as he goes. It looks like these grew from babyhood.

Another of the same anemones, on rotting sea lettuce.

And then there's the little blue anemone, rescued from certain death on the beach last October:

Brooding or Proliferating anemone, Epiactis prolifera, about 1/4 inch across. On a third clamshell, with several orange-striped babies, kelp, and green algae.

This anemone has a unique sex life. Young adults are almost all functional females; as they mature they become simultaneous hermaphrodites (having both male and female gonads at the same time, as opposed to being first one sex, then developing into another) capable of fertilizing themselves and others. (From Oregon Coast Aquarium)

She's still young; adults can be up to 2 inches across, so for now, she's female only. Since there are no males, she won't be reproducing for a while yet.

(So the infant green anemones in the clamshells aren't hers; they must have come with the kelp holdfast.)

Once she reproduces, she'll brood her babies for up to three months.

... larvae? ... Live on mother's column (digesting yolk, then catching prey) until at least 3 months old and 4 mm diameter, then crawl off. (From wallawalla.edu.)

She knows her own:

When starved, Proliferating Anemones will ingest young anemones that have become detached from the parent’s base; however, these are normally regurgitated unharmed, even after several hours in the gut. (OCA)

I can't forget Val, the largest anemone in my tank.

Burrowing anemone, Anthopleura artemisia. 4 inches tall and still growing.

These anemones reproduce sexually, which won't happen here, since she's a loner. Or by splitting, which she shows no inclination to do. She's probably had enough of that; when I got her, she was just a blob of torn tissue left on a beach, probably by a bird.

Just another jelly

Looks good enough to eat!

Hydroid medusa, against sea lettuce.

Working late tonight, trying to get a decent photo of a surprising snail. Photos tomorrow, probably.

Rust

Doing a bit of housekeeping in the hard drive, I found this forgotten photo.

Abandoned can, New Westminster Railroad tracks, 2009.

I've been examining the tinies in the tank again. I think maybe yesterday's mysterious bubble beasties could be hydroids. I'll try to capture some where I can get a better look.

Obelia and the Very Messy Limpet

When we go to the beach, I pick up a bag of veggies for the animals in my aquarium. The crabs love green sea lettuce; I often see them grab a floating leaf, tear it into chunks and gobble it down. They're fond of a side salad of red Turkish towel, too. The big brown anemone seems to do better when there is a bit of rotting kelp nearby. Hermit crabs like the red stuff; thin red algae and Turkish towel. Some hang out on the sea lettuce, picking at the surface.

Snails and limpets feed on fresh eelgrass, but the hermits like it best a bit aged, covered with weedy growths. They browse knee-deep in the "pasture", whether eating the weeds or searching for bits of detritus, I don't know.

Eelgrass blade, with fuzz and a couple of limpets.

The last batch of fuzzy eelgrass brought along a small limpet, as fuzzy as the grass itself.

Limpet, bubbles, and a city on a hill.

The limpet is about 1/2 cm. lengthwise, less than 1/4 inch. I looked at it through a magnifying glass, to see if the tiny spiral worms were alive, and found a thriving community, more diverse than I had expected. I've been trying to get photos ever since, difficult since I needed it to stay underwater so that the waving, feeding critters would be out. There was so much activity that, even in still water, the eelgrass blade floated to and fro.

Side view.

In the peak of the limpet shell, a new eelgrass plant is growing. Under its shade, there's a circular patch of bryozoans. The red blob above this, and red lines in other spots, are feeding tubeworms. At the rim, two tiny (less than a millimetre long) mussels are hanging on.

Empty worm cases (Spirorbis) on the top of the shell.

The feeding tentacles of many tubeworms, in the crevices between stalks and spiral worm shells, are only visible under a microscope; among them tiny crawling and swimming things wander about.

A mussel on the eelgrass. Maybe a millimetre long. And on its tip (look closely) there's another shell, possibly a limpet.

It would be much easier to examine this limpet shell without all the weeds cluttering up the view. Or so I thought, until I came to my senses and paid attention to them, too.

One branch, covered with buds.

More than buds.

The "weeds" are animals: hydroids, one of the Obelia* species. They are cnidarians, related to the jellyfish; the adults form stalked colonies, but the young start out as medusas, miniature jellies. The "buds" are polyps, some feeding, some reproductive. In the photo above, just above the centre, you can see one open polyp, feeding. The tentacles are tipped with stinging capsules that explode when a prey animal touches them, incapacitating it so that the tentacles can bring it down to the mouth.

When a polyp is disturbed, it shuts down quickly. Most of the ones I saw were closed. I guess I was scaring them.

A closed polyp, with the tentacles pulled inside a thin case.

Life cycle of an Obelia. Image from Kent Simmons, U of Winnipeg.

The reproductive polyp has no tentacles. Inside it, baby medusas form and are set free as they mature.

Empty reproductive polyp.

I saw one tiny stalk with the open tentacles at the top, hiding at the base of the eelgrass blade, either a new branch on the old colony or a young polyp, recently settled. It was too small, too transparent for my camera.

*Obelia. Sounds like a woman's name. Would you name a kid Obelia?

City of glass

This delicate beauty showed up in my aquarium. It probably hitchhiked on a piece of seaweed I brought home from the White Rock beach.

Glass animal

It's about an inch long, fully stretched out. I can't find it in my books nor on the web, but I think it is possibly some variety of hydroid, a Plumularia, maybe.

A hydroid is a community. Each circle of tentacles belongs to a separate animal. Looking at this one closely, I can distinguish several structures: segmented "feather" stalks with rows of zooids along the side, each brandishing its little spray of tentacles; a wrapped stem beneath, a few individuals consisting of a stem and a funnel shape, topped with tentacles.

Detail.

I found tons of interesting photos of Cnidaria (the hydroids' home phylum) on Google; what variety there is in this obscure "rock fuzz"!

• A diver's photo album includes tiny hydroids.
• Pearson College guide to ecosystems. Scroll 'way down to "Underwater at Race Rocks". One of the hydroids.
• Elasmodiver. Cnidaria. The glassy plume hydroid.
• SeaNet, Stanford. Phylum Cnidaria ...
• RaceRocks.com Several hydroid species on a scallop shell.
• A UK site with great photos. Keep clicking on "Next species".

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