Just chitons

Each stretch of shore has its own mix of critters and algae. On the Willow Point reef, I saw mostly green and red sea urchins, tons of ochre and leather sea stars, acres of encrusting bryozoans. Crabs and whelks and other snails. And limpets. There are always limpets, everywhere. And a fair number of chitons, huge and tiny.

Giant Pacific chiton, Cryptochiton stelleri.

These chitons are the largest species of chiton, worldwide. They may grow to 35 cm. long. This one was a big guy, about a foot long (30 cm.), maybe a bit more, measured against my shoe (27 cm.).

And a smaller one, about 18 - 20 cm. long.

I found several others, one exposed upside-down on the sand, his unprotected foot exposed to the sun's heat; I turned him over and covered him with seaweed.

And then there were the little ones:

Lined chiton, Tonicella lineata

These grow to about 5 cm. long. This one was smaller. When I picked up the stone he was resting on, being careful not to touch him, he fell off. Or let go on purpose. Here he is in the process of rolling himself up in a protective ball, like our familiar roly-poly wood bug. Afterwards, I nudged him back into the hole his stone had been in, out of the bright light.

Muddy buddies. Three lined chiton cuddled together in a sea urchin's hole. With a pair of snails.

More on sea urchins and their holes, tomorrow.

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Cada tramo de playa tiene su propia mezcla de habitantes, tanto animales como algas y algunas plantas. En Willow Point, a la marea baja, encontré por su mayor parte, erizos de mar verdes y rojos, cientos de estrellas de mar ocre y "de cuero", hectáreas completas de bryozoos encrustantes. Y cangrejos de varias especies, lo mismo de caracoles marinos. Y lapas. Siempre hay lapas, dondequiera. Y un buen número de quitones, tanto grandes como chiquitos.

Foto # 1: El quitón gigante del Pacífico, Cryptochiton stelleri. Esta especie contiene los quitones más grandes del mundo entero, midiendo hasta 35 cm. de largo. Este ejemplar medía unos 30 cm. o un poco más, usando mi zapato (27 cm.) de regla.

Segunda foto: Un quitón un poco más chico, midiendo de 18 a 20 cm. Encontré varios otros, incluso uno que se había quedado barriga arriba sobre la arena, expuesto al calor del sol. Lo volví a su posición normal y lo cubrí de algas para protegerlo.

Y los quitones chicos:

Tercera foto: Un quitón rayado, Tonicella lineata. Estos llegan a unos 5 cm. pero este fue un poco más chico. Cuando levanté la piedra donde se hallaba, teniendo cuidado de no tocar al animalito, éste se desprendió y cayó al suelo. En la foto se ve que está empezando a enrollarse para su protección, a la manera de nuestros animalitos comunes del jardín, los armadilídidos. Después de sacar la foto, le empujé suavemente hacia el hoyo de donde salió, donde no le pegaba el sol.

Cuarta foto: Tres quitones rayados, juntitos en un hoyo hecho por un erizo de mar. Y dos caracoles marinos.

Mañana, más sobre los erizos y sus hoyos.

Hitchikers and their kin.

My little home aquarium is a self-sustaining habitat. (Well, with a lot of work on my part, but that's just maintenance, making up for the lack of the tides which keep their home clean on the shore.) It's always full of life. Because over the years critters keep appearing, sometimes coming in on seaweed brought in, groceries for the current residents, sometimes sandwiched between barnacles I bring home to keep the snails happy. And sometimes they just sort of appear, whether brought in as eggs or floating in the clean water I collected at the shore. I'm cleaning the tank, scraping off brown algae, getting rid of leftover crumbs, and I see a tiny shape, sometimes just a hint of movement, a crab-like walk, or a waving tentacle. Something new living in the tank.

And I have to keep up the maintenance because I can't abandon my tiny friends, not without carrying every single one down to the proper level of the intertidal zone and releasing it safely. 

Green isopods arrive clinging so tightly to rockweed that I don't see them, even while I'm rinsing it off before I anchor it in the tank.

Rockweed isopod, Idotea wosnesenskii. Showing up on a piece of red alga. About 4 cm. long.

A fourteen-legger. Notice the hooks at the tip of each leg. They cling tightly to the algae, so that even with strong wave action (or me harvesting it) they are not dislodged.

And growing up in the tank is a large community of tiny isopods.

Isopods on an oyster shell. The largest are about 5 mm long. 

A large one, captured on its own.

Whenever I take a shell out of the tank, I find it covered in these critters, all running about, always in a hurry. I don't know what species they are.

A mussel shell, holding two isopods, and a couple of amphipods (the curly ones). The isopods always lay flat.

And this: I first noticed it a month or so ago. It was stuck to the glass below the sand level, only the size of one of the isopods, and looked like a baby limpet from that point of view. But the shape was wrong; it looked oval, not circular. Even with a lens, that was all I could see, but I thought it might be a chiton.

Two weeks ago, it turned up, now recognizable, on an oyster shell. And today it was on a small rock, which I took out, still keeping it underwater, to get a photo.

Woody chiton, Mopalia lignosa. With two orange-striped green anemones.

As far as I can tell, he's a woody chiton. If so, he will grow up to 8 cm. long. Today, he 1.7 cm.

He was not pleased with the trip. As soon as I replaced him in the tank, he hurried back to the oyster shell. These are shy beasties, hiding on the underside of rocks and shells. There, he barely moves from one day to the next, just peacefully eating algae and diatoms; he especially likes green sea lettuce, Ulva spp.. Tomorrow is a low-tide day; if the weather holds, I'll go find a handful of the lettuce for "Woody". And some eel-grass for the hermits, kelp for the crabs, barnacles for the carnivore snails, and ...

And no telling what else will hitchhike in.

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Mi acuario casero es un habitat que se sostiene vivo solo. (Bueno, aparte de mucho trabajo de mi parte, pero eso es mantenimiento solamente, debido a la falta de la marea, que en el mar les mantiene su casa limpia.)  Siempre sigue llena de vida. Porque año tras año siguen apareciendo criaturas nuevas. A veces llegan escondidos entre las algas que traigo a casa para la comida de los residentes ya presentes; a veces se cuelan entre los bálanos que mantienen felices a los caracoles marinos. Y muchas veces aparecen como por magia, tal vez habiendo llegado como huevos o como el plancton que flota en el agua que traje desde el muelle.Estoy limpiando el tanque, raspando algas invasivas, aspirando restos de comida, y veo algo que se mueve, apenas el movimiento ya que el animal es tan pequeño; el movimiento lateral típico de un cangrejo, o el ondeo de un tentáculo miniaturo. Algo nuevo que ahora vive en el acuario.

Y tengo que seguir con el mantenimiento, pues no puedo abandonar a mis amiguitos, no sin llevarlos uno por uno al sitio adecuado de su zona intramareal.

Isópodos verdes llegan cogidos tan fuertemente al alga parda, Fucus spp., tan apegados que no los veo, ni cuando estoy enjuagando las algas antes de instalarlas en el tanque.

Foto: # 1, 2: Isópodo de Fucus, Idotea wosnesenskii. Visible sobre un alga roja. Nótense los ganchitos en cada una de las catorce patas; estos se agarran tan fuerte al alga que ni las olas ni yo al trasportarla logran despegar el animal.

Y han crecido en el acuario una generación de isópodos muy pequeños.

Fotos # 3, 4: Isópodos en una concha de ostión. Los más grandes miden aproximadamente 5 mm. de largo. Siempre que saco una concha cualquiera del tanque, la encuentro cubierta de un gran número de esto, todos corriendo de acá para allá, siempre con mucha prisa.

Foto # 5: en una concha de mejillón hay dos de estos isópodos miniaturos y dos amfípodos; estos son los que se doblan, haciendo medio círculo.

Y esto: lo vi por primera vez hace un mes o más, apegado al vidrio debajo del nivel de la arena. Desde ese punto de vista se parecía a una lapa chica, pero la forma era diferente. Con una lente de aumento lo examiné y pensé que tal vez sería un quitón juvenil.

Hace quince dias estaba, ya más grande, en una concha de ostión y si era un quitón. Y hoy lo encontré en una piedrita. Lo saqué del tanque, manteniéndolo siempre en el agua, y le saqué una foto.

Foto # 6: Un quitón "de madera", Mopalia lignosa, creo. Con dos anémonas.

Parece que si es un quitón de madera. Si es así, puede crecer hasta los 8 cm.; por ahora mide 1.7 cm.

No estaba contento con su viaje. En cuanto lo regresé al tanque se fue a esconder bajo la concha de ostión de nuevo. Estos son animales tímidos que se esconden en la parte inferior de las piedras y las conchas de mar. Allí, no se mueve mucho; se mantiene allí tranquilamente comiendo algas y diátomos. Le gusta la lechuga de mar, Ulva spp.; mañana, que va a ser un dia con marea muy baja, si el tiempo lo permite, voy a la playa a buscarle un poco de lechuga marina para "Woody", y algo de hierba Zostera para los ermitaños, kelp para los cangrejos, y unos bálanos para los caracoles carnívoros. Y ...

Y quien sabe que otra criatura se subirá de pilón.

Bearing the world on his back

 In the bottom few metres of the intertidal zone, I found chitons. Many chitons, tiny to "giant", of at least 4 different species.

This one resists being identified. Is this burden he carries from a sense of responsibility for the world, camouflage, or just because of his attractive personality?

Hardly identifiable as a chiton at all.

Except from the underside. Mouth on the left.

He could possibly be a mossy chiton. Mopalia mucosa: they grow dark, bristle-like hairs around the outer edges. But the algae he wears make it hard to be sure.

He's carrying 5 barnacles of the larger local species, which with time could immobilize him under their weight. But he's not fazed; there's room for more.

I labelled the photo of his back.

4 species of algae, 2 of barnacles, mussels and limpets and a tiny hermit crab. There's probably more, hiding under the sea lettuce.

Tomorrow: the rest of the chitons.

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Entre los últimos metros de la zona baja intramareal, encontré muchos quitones, de varias especies, desde las más pequeñas hasta los que llamamos "gigantes".

Este quitón resiste la identificación. Lleva el mundo en su dorso; ¿será por su gran sentido de responsibilidad hacia su comunidad, para servir de camuflaje, o simplemente porque tiene una personalidad tan atrayente?

Desde arriba, casi no se puede identificar como quitón, pero boca arriba, se ve la forma. Puede ser un quitón "cubierto de musgo", Mopalia mucosa, ya que estos llevan pelos oscuros, tiesos, alrededor de las placas dorsales. Pero por la algas que lleva, es difícil distinguir la especie por cierto.

Lleva 5 bálanos de la especie local grande, los cuales con el tiempo pueden llegar a pesar tanto que se le haga imposible moverse. Pero no se da por vencido; hay lugar para más.

Marqué la foto con algunas identificaciones. Hay 4 especies de alga marina, 2 especies de bálanos, mejillones y lapas y un cangrejo ermitaño miniaturo. Probablemente habrá más, escondido bajo la lechuga marina.

Para mañana, dejo los demás de los quitones.

Sand delvers

Here's another of those 1950s photos, offered as an explanation of why I still flip rocks and dig through seaweed on the beach. I came by it honestly, trained from early childhood.

Mid-tide, Ferrer Point, 1954

I don't think I was in this group of kids. I would probably be over by the rocks, or wading out to where the crabs hid. I saw my first chiton on those rocks.

Location of this beach, and the towns from the previous post.

If you Google "Ferrer Point" and zoom 'way in, you can see people still walking on that sand.

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Esta es otra de las fotos que sacó mi papá en los años 50. Y tal vez muestra el porque me paso horas en las playas volteando rocas y levantando algas marinas; me acostumbré a ello muy niña. En la foto, un grupo de niños busca almejas y hace castillos de arena en la playa de Ferrer Point. No creo que yo esté en ese grupo; estaría más bién allá cerca de las rocas, o vadeando hasta donde los cangrejos corrían. Encontré mi primer chiton en esas rocas.

En el mapa se ve la Isla Vancouver, la Isla Nutka, donde se halla esta playa, además de los pueblos que mencioné en el primer post sobre estas fotos.

Si gugleas "Ferrer Point" y haces zoom a lo máximo, podrás ver gente gozando de esa misma playa en estos dias.

Colours under rocks

What a difference a few metres make! I've been on this beach (Willow Point), flipping rocks at low tide before, but this time, the tide was the lowest I've seen it. The last time, I saw crabs and small snails and hermit crabs and barnacles. Not much else. This time, every rock had a diverse community on the underside.

Wosnesenski's isopods, multi-coloured snails, limpets, a tiny, tiny clam, barnacles, spiral tube worms, unidentified eggs, and a possible red chiton.

I was chasing Wosnesenski's isopods; they're big and visible, but very fast, very motivated to get back underneath a stone. None of them stop to challenge me, like a shore crab will.

"I'm going to pinch you and crunch your shell! No matter how big you are!"

(Aside: what's that weird thing under the clamshell on the upper left?)

Wosnesenski's isopod (Pentidotea wosnesenskii) stubby isopod (Gnorinmosphaeroma oregonensis -the name is longer than the beastie), and red chiton.

This isopod ran away, as they do, but exposed a stubby isopod and a red blob, which the camera saw better than I did. Stubby isopods are small, at most 1 cm long, usually less.

Stubbies. I think there are two of them, stacked. Two flatworms and their eggs, a barnacle, and a small, red chiton.

Chitons are fairly common in the lower intertidal zone. So far, I've seen the giant Pacific chiton (up to 14 inches; the ones I've seen were between 5 and 6 inches long), the beautiful red-lined chiton, the woody (to 8 cm), the mossy (10 cm), and some hairy species, so buried under their overgrowth of algae that they were unidentifiable. But I hadn't seen one so small, and so red. I don't know the species; none of the 30 species in my encyclopedia seem to match.

A more usual find; a woody chiton, still very small.

Red giant

"What is this?" A girl I'd been talking to on the beach came running, holding a large, red animal, already rolling itself up into a ball.

Giant Pacific chiton, aka gumboot chiton, Cryptochiton stelleri.

It rolls end to end; rolled up like this, it measured a bit over 6 inches. That's side to side, I think.

From the brief glimpse I got of it before it curled up, it's like the much smaller dead chitons I found on the beach last month. Those were almost white, with tiny pinkish protuberances; their fleshy coating had eroded away.

The gumboot chiton can grow up to 14 inches long. This one, I think was a little less than that. A fully mature one may weigh up to 2 kilos.

The fleshy outer coat is hard and rough to the touch, with a slight give on pressure, like strong leather. The flesh, in the brief glimpse I got before the chiton rolled itself up, was a brownish orange.

To touch a gumboot is to feel the fuzzy texture of about 20 species of red algae that live on the mantle and give the gumboot its brick-red color. (From Monterey Bay Aquarium)

At home, I examined my photos closely. The red mantle is covered with tiny flower- or anemone-shaped stalks; whether they are algae or the mantle itself, I couldn't tell.

Algae? The grey stuff is fine sand from the beach.

After I found those dead chitons, I returned a few days later, and found the smaller one where I had seen it before. I brought it home in a double plastic bag (it was stinky!), soaked it repeatedly in hydrogen peroxide for several days, cleaned the rotting flesh away, soaked the rest in alcohol, and then dried it.

The eight internal shells are now visible. Because of their shape, they're often called "butterfly shells".

7 shells (also called plates or valves) are clearly visible. The eighth is almost hidden under the edge on the left.

Top of this chiton. The white mantle is hard and smooth, but those red knobs are rough. They drop off quite easily; they are probably algae.

Total length of the dried chiton: 4 inches, curved in as it is.

Most chitons cling tightly to their rocks; these gumboots are easier to dislodge, and sometimes they can be washed up by the waves. This live one was on the sand, near rocks.

Sometimes in the spring, great numbers of chitons gather on rocky beaches, probably venturing in from deeper waters to spawn. (Monterey Bay Aquarium)

We replaced the chiton on the sand at the water's edge and left him to find his way home. He was still rolled up tightly when I headed back up the trail.

Katy in black leather

The afternoon was sunny and warm, although the previous afternoon's snow still had not melted. Favouring my gimpy leg, I chose a beach for walking that is flat, flat, flat. Mostly hard sandstone, covered with rockweed; not too slippery, easy going.

I followed the tide out. At the base of an erratic, I found a community of whelks and chitons.

The erratic as first seen, about 3/4 tide.

Now, half an hour later, the water barely reaches the base. I could walk there.

I am always intrigued by these erratics, left behind by the glaciers eons ago. It's as if they levelled the ground, rolling it like a lawn, leaving only faint scratch marks, and then, on a whim, dropping a great chunk of rock in the middle. This one is about 4 metres tall (13 feet), judging by my height; I could not quite reach the green/yellow mark where the usual high tide covers the stone and barnacles.

At the base of the stone, on the seaward side, several chitons rested in a shallow pool.

I think this is the black leather (Black Katy) chiton, Katharina tunicata.

These grow to about 6 inches long; the ones I saw were around 3 inches. I touched a couple; they are hard and leathery, and were firmly attached to the rock.

Another, almost a blue-black. To get these photos, I had to balance on three points, feet on wobbly stones, leaning a shoulder against the rock on the far side of the pool, hoping not to fall in, trying to keep the camera dry. I'll try again another day, after the tide has fallen more.

Several chitons here, in a deeper spot in the pool. Two black Katies, and two much smaller, nicely patterned chitons, possibly lined chitons, Tonicella lineata. The star is a leather star, Dermasterias limbricata.

More on this beach's residents, tomorrow.

No lights, please!

Last February, among the barnacles I brought home for my intertidal snails, a small chiton was hiding. He joined the other beasties in the aquarium, and trundled about happily for some time, cleaning algae off the glass walls and the stones. Then he disappeared.

Much later, cleaning the aquarium, I found him, inside an old moon snail shell. He'd grown some, was obviously thriving.

Since then, I've seen him often, on the outside of the moon snail shell, sometimes deep inside, sometimes on the bottom. But always on the snail shell; he never explores the glass walls any more, nor the sandy floor, nor even other shells. The moon snail shell is home.

Woody chiton, Mopalia lignosa , on algae-encrusted moon snail shell, fleeing the camera.

Chitons are slow animals, as slow, almost, as limpets. (Although a limpet on a mission can trot right along.) And on the beach, the chitons don't seem to mind being partially out of the water at low tide. I thought that maybe I could get some clear photos of "Woody", and maybe get a close look at his spines with the microscope, if I took his shell out of the tank. I put him in a tray with a half-inch of water, and set up the lights and camera.

But Woody didn't approve. As I rolled the shell around to get him within reach, he kept turning, heading down, towards the bottom of the shell, under the water. There are light-sensitive spots on his plates; he saw those bright LED lights, and hated them. Every photo I took was of him hurrying away. I didn't even try to aim the microscope at him.

He never left the moon snail shell. It's his safe place.

Side view.

The small, soft spines on his girdle arise from light freckles. The girdle is quite flexible; at one point, he galloped up and over the limpet, lifting the edge of the girdle to fit.

I gave up and replaced his home in the tank. He stopped racing around; he must have been pretty tired. He's still on the moon snail shell.

Rust, sea lettuce, and a baby chiton

The tide was as low as I've seen it at Oyster Bay, and I was wading around the remains of old ships left decades ago as a breakwater.

Clammers, and remains of an old ship, draped heavily in sea lettuce.

A long ship, reduced to spikes and sea lettuce holders.

In a few inches of water between rusty girders, I noticed a little chiton, upside-down. Unusual; they're normally stuck tightly to the substrate, but maybe his perch had gotten too hot and dry for his taste.

I picked him up, and he immediately rolled himself into a tight ball. I didn't know they did that.

I think this the woody chiton, Mopalia lignosa; his hairy girdle is lighter, softer, and has shorter hairs than the common hairy chiton.

After a brief wait, since I wasn't moving, he started to unroll himself again.

Orange underside. Like a limpet's, his foot includes a mouth (not visible on the right) and is separated from the girdle by a space which includes the gills.

When I moved, he rolled up again, so I gently replaced him back in the water, foot down.

These chitons grow to about 3 inches long; this was a youngster. They live in the middle to low intertidal zone, mostly on the sides and bottoms of rocks. There are no rocks in the area where I found him, so he had to make do with rusty metal.

They eat mainly sea lettuce; he'd picked a good place for that; these old ships are loaded with the stuff.

With my nose to the glass

I've been watching some of the smaller life in my aquarium.

Like this female Calanoid copepod carrying her egg sac behind her.

The copepod is the basic food group for many marine organisms, including my anemones.

Some scientists say they form the largest animal biomass on earth. ... copepods almost certainly contribute far more to the secondary productivity of the world's oceans, and to the global ocean carbon sink than krill, and perhaps more than all other groups of organisms together. (Wikipedia)

In my tank, the copepods are about 1 mm. long, and visible only when the light hits them against a dark background.

The sand dollar was trying to climb the wall, pushing with the stripy spines until he was almost vertical. But there was nothing to eat on the wall, and he gave up and crawled back into the sand.

A tiny piece of broken crab shell, with the remains of a barnacle.

When the lined chiton came close to the glass, I was able to see the tiny hairs on its girdle.

I brought home two stones with big barnacles for the leafy hornmouth snails to eat. Once they were in the tank, the sand that came along with them got up and started to walk about. With a lens, I could see that they are snails, as small as fine sand grains. And in short order, they had all crawled down and merged into the sand on the bottom of the tank.

Meanwhile, back at the ranch ...

While I've been poking around weedy fields and stony beaches, life goes on apace in my aquarium. Snails are laying eggs, the amphipods are pairing up, and the anemones splitting up. (That's fine; that's how they multiply.) I counted 39 hermit crabs tonight, when I changed their water. About a third are youngsters; some are barely pinhead size - a small pinhead, at that. And there are two new crabs, a couple of millimetres across the carapace.

I've begun to bring in water from the shores at high tide again, instead of using the commercial aquarium salt and filtered water, since I learned that the local aquarium is using water from their doorstep. And my animals are much happier! Their colours are brighter, they're more active, a few that were damaged by the marauding crabs have recovered. The commercial salt has (probably) all the minerals and trace elements sea creatures need, but it's all dead stuff. Sea water is alive; it's swarming with planktonic plants and animals, the base of all marine food webs. And so is my aquarium, now.

Limpet on the glass, scraping away at spots of green algae. The pointed extension is its gill. And the bright green tube just inside the shell is limpet poop, digested algae.

A small chiton, about an inch long. It arrived on a rock with barnacles for my snails.

Another recent addition. The crabs ate his companion before they were deported.

Several small anemones have appeared in the tank. This one, I think, is an orange-striped green anemone, well to the back of the tank on the old abalone shell.

That limpet again, still eating, with its antennae extended; celebrating that wonderful feed coming up!

Down at the beach, looking for water, I took this next photo. The incoming tide usually is carrying something: driftwood, ripped up eelgrass, long kelp whips, scraps of sea lettuce, and this last week, hundreds of lions' mane and moon jellies. This time, the algae was the colour of yellowed sea lettuce, but instead of sheets, it was a thick paste, with thicker blobs.

Green scum, unidentified algae.

I waded in and collected my two gallons of water, pushing aside the algae. It was fine; my anemones received it with enthusiastically waving tentacles.

Bathed mud crawlers

I keep finding chitons. Under rocks, in tidepools, on soggy mud, under blackish algae, there they are, not moving, almost invisible, looking like oval mud patches surrounded by shreds of algae. When I've seen one in a sludgy pool, there are sure to be more, sometimes in plain sight, although I hadn't seen them.

Years ago, on Stories Beach, Laurie and I found a lined chiton. Easy to see, away from its favourite red algae, and a fast crawler besides. Easy to identify.

Lined chiton, Tonicella lineata, 2010

This year's finds are more challenging. Most of my photos have turned out like blurry blobs of mud. But I caught two chitons on the underside of rocks, lifted them into the sunlight, and poured water over them until the mud washed away. And then it turns out that they are as beautiful in their own way as their showier kin.

Mossy chiton, Mopalia muscosa.

The outside rim, called a girdle, spiky and hairy as it is, is a mud catcher. And the eight plates covering the centre come in variable colours, from grey to brown to green.

Zooming in to see the pattern of the plates. The head end is to the left and the plates overlap each other, going from head to tail.

Brown and yellow, with a couple of decorative accents, red algae.

Zooming in on the head. 

These chitons are night crawlers. In daylight, they sleep. Even disturbed by a rude rock flipper, and given a good bath, these two barely moved. The first one lifted an edge, then flattened itself more tightly to the rock; that was enough exercise for the moment.

These two were on the 50th parallel.