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.

Stowaway

The tide was low, and it had stopped raining. The sun peeped around the clouds for a minute. I went north of the city to Orange Point; there's a muddy trail going down to a small, rocky beach. I'd never been there at low tide before.

And the rocks go on underwater.

In a small sandy patch, I found five Gumboot chitons. All very dead, much battered about, with all the red colouring sandpapered off. One was in slightly better shape; I took a photo.

Giant Pacific chiton (Gumboot), Cryptochiton stelleri, belly up. Mouth to the left.

He wasn't pretty; I processed the photo for my records, not to share. Until I looked more closely: he's carrying a passenger.

The commensal polychaete worms Arctonoe vittata or A. pulchra can sometimes be found in their pallial groove, as can the pea crab Opisthopus transversus. (WallaWalla)

The pallial groove is the space between the foot and the mantle, where the gills are located. And in this chiton's groove, there's a pea crab.

Zooming in. The crab is hiding behind his pincer. The white blobs are the gills of the chiton.

I don't know if the crab was alive or dead. I did see another of the chitons with a dead pea crab beside it, as if it had crawled out as the chiton died.

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La marea estaba baja, y había dejado de llover. El sol se atrevió a asomarse detrás de las nubes por un momento. Fui al norte de la ciudad, al punto Orange (Anaranjado); allí un sendero lodoso baja hasta una playita llena de rocas. Nunca había visitado esta playa a marea baja.

Primera foto: La playa, el estrecho, la isla Quadra. Y las rocas siguen hasta debajo del agua.

En una pequeña sección arenosa, encontré cinco quitones Gigantes, Cryptochito stelleri, todos muertos. Muy muertos, maltratados, con su piel color rojo raspado hasta dejar a los animales encuerados. Uno estaba en condiciones tantito mejores: saqué una foto.

Segunda foto: el quitón, el pie al aire. La boca se ve a la izquierda.

No era una foto bella, pero la procesé para mis archivos: no pensaba publicarla. Hasta que la miré más de cerca y descubrí que el quitón llevaba un pasajero.

A veces se pueden encontrar los gusanos Arctonoe vittata o A. pulchra dentro del surco paliativo, como también se encuentra el cangrejo guisante Opisthopus transversus. (WallaWalla)

El surco paliativo es el espacio entre el pie del animal y su manto, donde se encuentran las branquias. Y en el surco de este quitón, hay un cangrejo guisante.

Tercera foto: viendo más de cerca: el cangrejo efectivamente escondido tras su quela (pinza). Las cosas blancas son las branquias.

No sé si en cangrejo todavía vivía. Vi cerca de otro de los quitones un cangrejito, como si se hubiera escapado mientras moría el quitón. Pero también estaba muerto.

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.