A grainy hand and 3 hairies

Interlude. Between outings to forest and shore, I come home to a dozen busy hermit crabs wanting dinner. Sometimes they even pose for photos.

A grainy-hand hermit, Pagurus granosimanus.

Eating dried kelp.

There are 5 medium-sized hermits, both grainies and hairies. The grainy-hand hermits grow up to 2 cm. long, counting the shell they've chosen; hairy hermits are just a bit smaller.

They're picky about the shells they use. I bought a package of these imported white shells; nice, clean shells with a wide opening, not too heavy. The grainy-hand hermits like them but the hairies won't touch them; they prefer whelk or periwinkle shells, or even the invasive mud-flat snail shells.

I'm not really sure how many baby hairy hermits there are; I count a half-dozen any day, but some of these, at least, grew up in the tank, and I have seen some so small I only knew they were hermits by the way the shell moved. Snails inch themselves along; hermits scuttle.

One of the larger of the tinies, a hairy hermit about 5 mm. long, shell and all.

They all love dried kelp. I cut off chunks for them about 2 cm. long.

About as small as the camera can capture. Another hairy hermit, Pagurus hirsutiusculus.

This one was perched on a small barnacle which had attached itself to a mussel. The white strands are the mussel's byssal threads, by which it has glued itself to the wall of the aquarium. Each thread is about the diameter of a human hair. Off to the right side, there's a copepod female carrying her egg sac. The red dot is her one eye.

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Intermedio. Entre vueltas por los bosques y las playas, regreso a casa donde me esperan mis cangrejos ermitaños, queriendo cenar. A veces hasta se detienen para que les saque una foto.

Fotos:

#1. Un ermitaño de mano granosa, Pagurus granosimanus.

#2. Comiendo quelpo resecado. (Y mojado ahora, claro.)

Hay 5 ermitaños de tamaño mediano,  P. granosimanus y P. hirsutiusculus, los peludos. Los granosimanus crecen hasta unos 2 cm. de largo, con todo y concha; los peludos son un poquito más chicos.

Son algo quisquillosos en lo que respeta a las conchas que deciden ocupar. Les compré un paquete de estas conchas importadas, limpias y blancas, con boca amplia, no muy pesadas. Los ermitaños de mano granosa las usan, pero los peludos ni los tocan; prefieren conchas de bocina o bígaro e inclusive del caracol invasivo Batillaria attramentaria.

No sé por cierto cuantos de los ermitaños peludos juveniles viven en el acuario; puedo contar, cualquier dia, una media docena, pero algunos de ellos crecieron aquí en el acuario, y he visto algunos tan miniaturos que solamente los reconocí por su manera de moverse. Los caracoles se arrastran paso por paso: los ermitaños corretean.

#3. Un ermitaño peludo juvenil. Mide aproximadamente 5 mm con todo y concha.

#4. Les gusta el quelpo seco. Les corto pedacitos de como 2 cm. de largo.

#5. Este es a lo más pequeño que mi cámara puede captar. Otro ermitaño peludo. Se había subido a un balanito, el cual a su vez se había fijado a un mejillón. Los hilos blancos son los bisos del mejillón, con los cuales se ha adherido a la pared del acuario. Cada biso tiene el diámetro de un pelo humano. Al lado derecho se puede ver un copépodo hembra llevando su saco de huevos. El puntito rojo es su único ojo.

Growing hermit baby

It's been a while since I had photos of the critters in my aquarium. Somehow, the light is never right, or the residents are in too much of a hurry. Or too small.

That's what it was with today's hermit. A couple of months ago, I noticed two small hermits in the sand, so small they were only recognizable as hermits by the way they moved. Sand grains in pinhead-sized shells. I don't know how they arrived; whether they were born in the tank or hitched a ride in on a bit of seaweed.

But they grew. They found themselves larger shells, still not much bigger than a pinhead. And now I could see legs. With the next size up, I could recognize each one; one had yellow legs, the other has black legs with prominent white patches. Two different species, then.

Little yellow-legs grew faster and changed shells more often. And today he was wearing the largest yet, still only about 4 mm. long. And he came right up to the glass, and his legs had turned orange with blue spots!

Orange legs with blue spots, red antennae, eye stalks, antennules.

And I think he's a grainy-hand hermit, because of the blue spots on his legs. So he very well could have been born in the tank; the adult grainy-hands had been pairing up a while ago.

While I was trying to focus on him, other critters showed up:

Limpet, feeding

Green shore crab, photobombing.

For comparison: here's an adult grainy-hand hermit, from a previous shoot.

Orangey legs with blue spots, red antennae, eye stalks, antennules. Much bigger, of course.

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Hace tiempo que no he subido fotos de los invertebrados que viven en mi acuario. Por alguna razón la luz no servía, o si no, los residentes tenían mucha prisa. O estaban tan pequeños que apenas se veían.

Eso es lo que pasó con el ermitaño de hoy. Hace dos meses vi dos ermitaños miniaturos en la arena, tan chiquitos que solamente los reconocí por su manera de correr. Granitos de arena en conchas tamaño cabeza de alfiler. No sé como es que llegaron al tanque, sea que aquí nacieron, o tal vez vinieron entre la hierba de mar que traje para gimnasio y comida para los otros animales.

Pero crecieron. Se buscaron conchitas más grandes, aunque todavía parecían cabezas de alfiler. Pero ahora se podían ver sus patitas. Y con la siguiente muda, les pude dar nombres; se distinguían el uno del otro. Uno tenía las patas amarillas; el otro tiene patas negras con manchas blancas. Así que son de especies diferentes.

El de las patas amarillas ha crecido más que el otro, cambiando sus conchas más frecuentemente, cada vea a una concha más grande. Y hoy llevaba la más grande hasta ahora, apenas, todavía, de unos 4 mm. de largo. Y se acercó a la pared y vi que sus patas se han vuelto anaranjadas, y tienen puntos azules.

Foto: aquí está, con patas anaranjadas con sus puntos azules, las antenas y los pedúnculos oculares rojos, también las antenulas.

Creo que es un ermitaño de manos granosas, Pagurus granosimanus, por los puntos azules en las patas. Si lo es, bien podría haber nacido en el tanque; hace un tiempo, los adultos se estaban apareando.

Mientras trataba de enfocar, otros residentes del tanque pasaron en frente.

Foto #2: una lapa, comiendo algae.

Foto #3: un cangrejo costero haciéndose un "photobomb".

Foto # 4: Un ermitaño P. granosimanus adulto, para comparar. Tiene patas anaranjadas con puntos azules, y los pedúnculos oculares, las antenas y las antenulas son rojas. Claro que es mucho más grande.

Double header

Another couple of photos from old storage. These were tiny critters from the aquarium, back in 2010. I had removed them to a plastic lid to look at them.

And here's a critter with two (or is it three?) heads.

Three stubby isopods, and one miniature hermit.

Hermits don't seem to mind having stuff piled on top. This little guy is carrying two stubbies.

Stubby isopods: about 6 mm. long. Their scientific name, Gnorimosphaeroma oregonensis, is 'way longer than they are.

The hermit, out from under the isopods. And a mussel, reaching out.

Mussels "walk" by extending a long foot, grabbing, and contracting the foot, reaching, grabbing, shrinking, over and over. It's a slow process, but they're not really in a hurry. Once they've found a good spot, they'll tie themselves down and stay put.

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Estas son otras fotos que se habían quedado sin procesar, desde el año 2010. Son animalitos del acuario; los había puesto en una tapa de plástico para observarlos.

En la primera foto, aparece un animal con dos cabezas. O no; son tres criaturas amontonadas. Encima, un par de isópodos "chaparritos", Gnorimosphaeroma oregonensis. Y abajo, un cangrejo ermitaño, muy pequeño. Los isópodos miden 6 mm. o menos.

En la segunda foto aparece también un mejillón miniaturo, con su "pie" extendido. Los mejillones caminan extendiéndo ese pie, agarrándose de lo que toquen, contrayendo el pie, jalando el cuerpo hacia el nuevo punto de contacto. Muy lento, pero los mejillones no tienen prisa. Para la mayor parte de su vida, se van a quedar atados en un solo sitio. No necesitan buscar comida; filtran el aqua que los baña.

Tiny climber

No matter how well I scrub the inner walls of my aquarium, the edges stay green. Where the glass is joined with silicone, algae grow, becoming part of the adhesive material. And the littlest hermit crabs climb these strips of algae.

Hi, there!

MiniHermie

I walked on the shore of Oyster Bay at low tide, collecting eelgrass for my hermit crabs. A new one came along for the ride.

Mini-hermit.The seaweed strand is like a fine string.

I took his photo in a plastic cup 2 inches across. The circle around the centre is 5 mm. wide, which makes MiniHermie about 3 mm long, shell, extended pincers and all.

Orange striped legs, a bit of blue, and striped antennae.

I added him to the tank, and he floated down until he reached the eelgrass, and grabbed on. I probably won't see him again until he grows up a bit.

Made his day!

Baby hermit is king of the castle today. And he's won the prize, too!

"Yummy shrimp pellet, and it's all, all mine! And nobody can steal it while I'm up here!"

Not a pinhead

The camera's one eye is better than my two, even augmented by a big lens. I spent the afternoon searching for the pinhead hermit crabs in my tank, trying to get them to come to the glass, and then to sit still for a minute, long enough for the camera to find them and focus. (Okay, half a minute? Please? If I give you some yummy food?)

They weren't interested. But a couple of their slightly larger friends took the bait. And the shrimp pellets make a good measuring stick, 3 mm. (1/8 inch) long.

The pellet is almost larger than the hermit (sans shell).

These tiny hermits are orange and white. They have the eyes, antennules (those waving flags in the middle of the forehead) and banded antennae of the hairy hermits, but an adult hairy is green or brownish, with blue patches on his knees.

A young adult hairy hermit, turning green already. Big enough now to hold the pellet in her chelipeds.

Side view of the same hermit. Look closely: the shell is populated with tiny tentacled critters, visible from the side and also from the top. The "tail" is one tentacle of a two-tentacled worm who has taken up residence in a tiny hole. 

I'll make another attempt to get photos of the pinhead* hermits. Their colours are contrasting dark brown and white.

*And I measured a standard dressmaking pin's head; it's 1 mm. across. Now, how will I convince a hermit to pose with a pin?

All those little eyes!

I had brought in a fresh batch of eelgrass for the aquarium, and a hermit crab in berry found herself a safe place there, far above the marauding crabs and nosy fellow hermits, where she could do a bit of housekeeping, and give her babies a bath.

I happened by just at the right moment to see what she was doing and took photos and a video.

Ma hermit and family.

This was three weeks ago, just before my family arrived and we took off on vacation. When I was back home and settled in again, she seemed to be baby-free.

I cleaned the tank, added fresh water, and, as usual, screened the old water before I discarded it. First, I strain out the big stuff, bits of seaweed and so on, look it over carefully, collect any stray critters, and dump the rest. Then I run the water through a fine sieve, check the sieve for moving critters, and replace them in the tank.

Finally, I strain the water through a coffee filter, and look over that under a bright light, watching for movement, even if the animals are too small to really see. And here, I found two tiny dots, about the size of copepods (under 1 mm.), that moved too slowly for copepods, and too fast for snails. I captured them with an eye-dropper, and looked at them under a microscope.

I could see, there, the tiny coiled snail shells. (I'm glad some of my baby snails don't make it, and leave their shells for other babies.) And in front of each miniature shell, I could also see the two tiny dots that were their hermit crab eyes, looking up at the world.

They went back in the tank. Maybe they'll have a chance to grow up.

Tiniest hermit

I caught just a hint of movement in the depths of a ruined holdfast. Hermit-type movement; the constant flick of antennae and waving pincers, in a place where none of my smallest hermits can fit.

I had to wait, but eventually, "Tiny" came out to get a look at the world. (They do love to climb!)

"I'm the king of this castle!"

The hermit crabs below him are a couple of the smaller hairies, in half-inch mud snail shells. Tiny is wearing a new Nassa shell, in blue and pink. These shells lose their colour as they grow, and are usually a mix of greys and off-white.

A smidgen of curiosity

Whenever I bring home seaweeds for my tankful of hermit crabs, I wash it and examine it closely before I plant it. I'm looking for the unexpected hitchhiker, the stray scale worm or baby starfish, the unidentified egg cases, the critters I've never seen before. There's always something.

After the seaweed is washed and planted, I set aside the water, usually overnight, to settle out. In the morning, I may find a half-dozen sharp-pointed snails climbing the walls of the bowl; tiny specks only identifiable as snails by their actions. Or a tubeworm or two may have set up housekeeping in the detritus. Maybe there's even a miniature clam; it takes a sharp eye and a lens to see these as they twist themselves down under cover of the muck.

One morning a few weeks ago, a speck almost too small to be seen was scrambling across a gap between sand grains. The motion looked more like a hermit's gait than the smooth glide of a snail or the sideward slide of a clam; faster, and more erratic. But it was too small to identify, even with the lens; I had to get out the microscope.

It was a hermit. Without his shell. I couldn't add him to the tank like that; he'd be swallowed by a barnacle or an anemone in an instant.

I kept him in a plastic cup while I prepared a batch of shells for him to choose from. All the tiny ones I had were far too big, but I'd seen before how the babies deal with that; they use the broken tips. I crumbled a bunch of shells and spread them in the cup.

A few hours later, the baby hermit was dressed; still too small to see clearly without a lens, but safely protected from barnacles, at least. He went into the tank with the big guys. And disappeared.

I was watching another very small hermit yesterday, when an smidgen of something orange came up to the glass and stared at me. My baby hermit, growing up!

Smile for the camera!

He stayed there for a while, long enough for me to take some photos, then run to get a pin for a size comparison.

With an ordinary dressmaker's pin, on this side of the glass.

He watched me for a while, then turned and wandered off. Later, wanting to show him to Laurie, I looked and looked, with a lens, without, with the water removed (low tide day, critters!); I couldn't find him anywhere. Never mind; I know he's there, somewhere.

What amazes me most about these critters is their intelligence and personality, even when they're no bigger than a grain of sand. It must take some ability to sort shells, choose the right one for your size and strength, make sure it's clean and empty; talents that even this pinhead critter uses. They're picky about their shells, too; they they test them for calcium content, shape, rollability, and something else; coolness? They like to wear the styles their peers are wearing. But they're mentally flexible enough to try something new when there are none of their favourites around.

But more than that is their curiosity about the world around them; this habit they develop of staring at me or the camera through the glass; their enthusiasm when they find something new to climb, a new vantage point, or just something to explore because it's there.

And all this goes on in a brain the size of the sharp point of that pin!

Teeny-tiny hermit crabs!

The tide was almost at its lowest ebb when we went to Boundary Bay Wednesday afternoon. We walked out more than halfway to the border marker before the water came racing back in.

I was collecting veggies for my hermits and crab, and out that far, the harvest was good; a varied menu, fresh and green. I brought home two varieties of sea lettuce, a handful of eelgrass with its roots, eelgrass with diatom fuzz, a bit of green tuft, a complete rockweed attached to a shell, and a "head" of sea hair. And for the three whelks that have grown up in the tank, I collected several clamshells hosting colonies of barnacles.

I washed everything at home, and planted the greens in the aquarium. There were too many clamshells, but I put the best in the tank and left a couple in the washing water while I decided what to do with them.

A while later, I saw movement in the sand and shreds of seaweed in the bowl. It was odd; not the curving, speedy swimming style of an amphipod, nor the jittery dance of a copepod. Not the frantic waving of a worm;  not a snail dragging its shell along; something walking. The animal was too small to see clearly, in the muck and underwater. When I tried to collect it with my eyedropper, it scuttled away. Definitely not a swimmer.

With the lens, I could see a hint of transparent legs. And it ran backwards, like a hermit.

I eventually trapped it, and examined it with the microscope. It is a hermit crab, less than 1 mm. long. And it was nude; a precarious state, making him a tasty morsel for any passing critter, even a barnacle.

I can't resist the collector's bug. I have boxes and bottles of little shells. And one small box holds pinhead shells. I went through them with a tiny paintbrush, collected all the snail shells and gave them to the hermit. Within a few minutes, he had moved into one, and was examining a second. Hooray!

I found a second hermit, a bit bigger. He joined the first, and chose the largest of my pinhead snail shells.

Two hermits, with extra shells. The larger one is checking out an alternate shell. He didn't like it, and has kept the one he's wearing here. Shell and all, he's just over 2 mm. pincers to tip.

I'm keeping them for now in a half-cup of water, with a few fragments of sea lettuce and hair. They seem contented enough, so I'll give them a chance to grow up a bit before they join their cousins in the tank.

Babies growing up!

Even a worm can be beautiful:

Polychaete on barnacles

I moved all my animals into a larger tank two weeks ago, transferring the sand, the planted eelgrass, the stones and shells, then the hermits and crabs once everything was going again. While I was combing the sand with my fingers to make sure I got out all the scrambling critters before the serious earth-moving started, I came up with a 3-inch polychaete. I don't know who was more startled, and I dropped it and/or it slithered out of my hand instantly.

The only worms I have brought into the aquarium have been microscopic. I've been watching them grow and make their tunnels, skinny red wires reaching up to the sand surface. I'd seen no sign of one of these big (and they do get big!) paddle-footed predators. It must have grown up in the tank in the few months it's been operational, since the beginning of September.

(The one in the photo is from 2010; I didn't chase the newcomer down. I'll let it grow for a bit.)

And something small, that will grow, soon enough:

New "grain of rice" hermit, on a fragment of molted crab shell.

By the dotted antennae, I gather he's a hairy hermit. He's too small to see if he has blue knees.

Tomorrow, weather permitting, the beach!

Hermit in a black shell

The tide was high at Centennial Beach, but this little guy was exploring the upper level.

"You can't see me!"

"Well, maybe you can ..."

"So I'm outta here!"

He tickled, running over my palm, but I held on and put him down carefully on the stones.

Well, look what Father Time brought me!

A whole, brand-new, unused, not even test-driven, sparkling-fresh year to play with! Wonderful!

And here's a brand-new hermit, to go with. He`s just molted and is hardening up before he goes hunting for a new shell.
A favourite from January of last year.

Now what shall we do with it? (The year, that is.)

Worth the work

A marine invertebrates aquarium needs babying; the ocean the residents come from is a complex environment, always changing, always refreshing itself, always in motion. They won't tolerate stale or quiet water or boring food.

I have a routine; I check and adjust the water pump daily, check the temperature and lighting, and add an appropriate amount of foodstuffs, taking care to vary the diet as much as possible. Every second day, I clean the filter, replace about an eighth of the water with fresh sea water, and remove large chunks of leftovers. As needed, I re-arrange or replace the plantings and playground equipment (large curvy shells, clumps of barnacles and/or mussels, stones); the crabs are constantly uprooting, tunneling, rock-flipping, sometimes to their own disadvantage.

Tiny hermit up a eel-grass and sea lettuce "tree".  All the ambulatory critters love these.

At least once a month, I call it low-tide day*; drain out most of the water, remove the animals and seaweeds, scrub the algae off the inner walls, and rinse the sand beneath. The first rinse water comes out thick with decaying plant matter. I always have to check it carefully and run it through a filter (coffee) to see if any of my critters got washed out with it. There are usually a few amphipods and plenty of copepods. Barnacle and anemone food, on the hoof. I put them in clean water and return them to the tank when I'm done.

Some of the animals, yesterday, refused to leave the filter. They ran around the bottom, holding on, not swimming like amphipods do. They were almost transparent, and too small to see clearly; what I was seeing was the way the light glinted off their wet bodies. I had to swish them around in the water to dislodge them, then shake the filter to get them out. Interesting.

But I was busy, so I set them aside until the aquarium was full again, and then poured them all in.

Later, my work finished, I was checking the leftover rinse water before I dumped it, and another of these beasties turned up in the filter. This time, I went for the magnifying glass. And it was a hermit crab! I've never seen one so tiny.

Newborn greenmark hermit, not wearing a shell  yet. About 2 mm. long.

I had noticed some mating behaviour in the tank, earlier. Male hermit crabs choose a female, and hold onto her, sometimes for days, until she consents to mate.** I'd seen a couple of adult greenmarks dragging occupied shells around; it's springtime, after all. But I never expected anything to come out of it, not in my small tank. But here they were; a whole family of baby hermits!

Green shore crab with rider.

Here's a tiny one, walking on the pincer of a green shore crab. I saw this guy for the first time last week, and wondered how he got here. Now I think I know. He's much bigger than yesterday's babies already.

"Got my eye on you." Greenmark hermit with the crab's eye in the background. The crab is about 1/2 inch across the shell.

*I know; the ocean does it twice daily. I'm not an ocean.
**See two previous posts on mating hermits: "A friend for Boy Blue" and "Little Bo-Peep is fast asleep".

Hermits bred in captivity!

Story tomorrow; I've been up all night watching them.

Newborn greenmark hermit.

Now I'm probably too excited to sleep. Goodnight, anyhow.