Chameleon lichen

After a few days of strong winds, the forest floors are littered with broken branches, dead leaves, conifer needles, and lichens; clumps and threads and whole branch-loads of lichens.

Two lichens; Lungwort and a beard lichen. On a Bigleaf maple mulch.

High on the trees, where the rain drains away quickly and the lichen is exposed to sunlight, the thallus is a mix of browns, from pale beige to dark chocolate brown, to a yellowish mid-brown. In the shade, where it's still dry, it's a paler greenish-grey. Tossed down here onto the wet ground, and then rained on, it turns a bright green on top, and a pale blue-grey on the underside.

The beard lichen, those pale threads mixed in with the lungwort, stay the same colour whatever the weather.

I didn't know this:

L. pulmonaria has the ability to form both vegetative propagation and sexual propagules at an age of about 25 years. ... Dispersal by vegetative propagules (via soredia or isidia) has been determined as the predominant mode of reproduction in L. pulmonaria. ...In this method, the protruding propagules become dry and brittle during the regular wet/dry cycles of the lichen, and can easily crumble off the thallus. These fragments may develop into new thalli, either at the same locale or at a new site after dispersal by wind or rain. (Wikipedia)

25 years! Lichen is slow-growing. How many years does it take to completely coat a tree, like the one I posted yesterday?

Decorator colours

The plumose anemone in my tank has a brown column and  beige tentacles, a common combination. Often, though, they are white on white; a white column, and whiter tentacles. I had never seen one with a green head before.

Plumose anemone, Metridium senile in the tidepool under the glacial erratic. With green tentacles.

I browsed images on Google; I found a few white "Mets" with pale green tentacles, always in photos taken during a dive. This one is in a few inches of water. And that was the colour as my eyes saw it; I used the flash, because the anemone was in shade, but those tentacles were a definite blue-green.

Another. This one has white tentacles, but the base is a pale blue.

This one matches the one in my tank. Some of the red blotches around it are tubeworm "flowers".

Another "normal" M. senile.

Deep under the rock, starfish wait out the dry spell. The flat, spread out anemone seems to be a burrowing anemone, with its mouth exposed. Must have just eaten something. Maybe one of those little fish?

More vivid colours. A deep pink tubeworm, still fishing while the water lasts. The pink-tipped green anemones below have shut down for now.

Even the hermit crabs are wearing party colours. I spotted this one with those bright blue pincers, like the one I brought home last week.

Three hermits, a dead kelp crab,and limpets. The deep red  critters at bottom right are not fish; they're shreds of seaweed.

Kelp crabs are usually a dull olive green, sometimes greenish brown. I don't know if this one was joining the explosion of colour in his lifetime, or if there's some sort of blue-green algae that took over his carapace and legs after he died.

This photo was taken aiming straight down into a foot-deep rounded hole. There are many of these near the bottom of the intertidal zone; circular holes, smooth-walled, looking like someone at some time removed a bowling ball from the rock. What causes this? I don't know.

I am always on the lookout for nice whelk shells for my hermits at home. Here, around this erratic, there are many whelks, all healthy and shiny, but no empty shells. And almost every hermit crab I saw was wearing a smashed and broken shell. What happened to the fresh shells?

I feel sorry for these hermits; the ones I brought home were quick to switch into intact shells; they do know the difference. I almost feel like collecting some decent shells from my tank and spreading them around this tide pool. Or would the tide immediately haul them off and slam them against the rocks until they were full of holes?

Questions, questions.

You are what you eat

Northern winters are tough on the little beasties that live at the intersection of sea and shore. Temperatures change, often drastically, in the course of a few hours. Storms toss whole colonies up on the beach, bury them in mounds of slimy, rotten eelgrass, drop logs on top of them. Cozy shelters in the seaweed are stripped bare; on the scoured stones, there is nothing left to eat, nothing to hide a scuttling crab from the myriads of hungry birds following the tide line.

My tank critters are spoiled. The temperature stays put; so does the water. Food drops from on high every day. There are no birds, and the cat doesn't relish getting wet.

Grainy-hand hermit on the remains of a kelp holdfast.

But even here, winter brings its losses. I comb the beaches year-round, searching for salad fixin's and gym equipment for the hermit crabs. In summer, there are bright sheets of sea lettuce, tall stalks of eelgrass, some loaded with delicious hydroids and diatom fuzz, knobbly Turkish towels and washcloths, long, green hair, stubby rockweeds, and more. But in winter? Bare stones, washed-out shreds of unidentifiable weeds, stripped of anything edible. And tea-leaf black, dried eelgrass.

In earlier years, the tank in winter gradually lost all its greenery, until the hermits wandered about disconsolately on bare sand and stone. I supplemented their diet with human food, sheets of green algae meant for sushi wrappings. They liked that, but it fouled the water.

The last couple of winters have been different. A red sheet algae established itself in the tank, and now grows as enthusiastically as the land plague, Himalayan blackberry. I have to keep cutting it back with every weekly water change. But at least there's something fresh to eat, and somewhere to climb.

Red algae is even trying to grow on the hermit's shell.

The change in diet has influenced the colours of some of the tank's residents. Red are redder, greens are browner. The colour of the shrimp's innards changes day to day, depending on his last meal; red today, transparent tomorrow.

And even the normally transparent copepods are striped with red and yellow. Look closely at the hermit above; there are a dozen copepods visible on his shell.

Three females with eggs, one male; the rest, I can't tell.

Most copepods have one red eye, a streamlined body, and a forked tail. The females carry their eggs around behind them; usually one pouch (Order Calanoida), sometimes two (Cyclopoida), one to each side. In the dark one at the lower left, the pattern is easy to see; red eye above, green bag beneath. The small, pale copepod at upper left may be a male of the Cyclopoida; his long, forked tail is just visible.

Drawing adapted from one by Jesse Cladgett.

When purple is green

When they're babies, purple shore crabs come in all colours from creamy yellow to green to red or even bluish. Most adults are purple or green.

Green shore crabs are mostly in shades of green, although some are dark red or purple. Otherwise, they look like purple shore crabs and live under the same rocks. It's usually easy to tell them apart, though, because the purples have polka-dotted pincers. The greens have plain pincers.

But then, there are the colour morphs. Some purple shore crabs are all over green, and they don't wear polka dots.

Green purple shore crab with a cracked carapace.

(I don't know how she got hurt, or how old the injury is. One of my students, a 9-year-old boy, brought her to me as is. He says that's how he found her. She was quite lively, in spite of the damage.)

So how do I know she's a purple? Because green shore crabs have hairy legs; purples are "nude". Their Latin name is Hemigrapsus nudus.

Side view. Clean-shaven legs.

She only stayed on my hand for a few seconds, then she scrambled off and dropped into the rocks. But before she went into hiding, she stopped to warn me off:

"Go home, huge monster!"

... thereby showing me her green, non-polka-dotted pincers.

These crabs lose pincers and legs with no noticeable disruption of their lives. The cracked carapace won't heal, but at next molt, she'll have a nice, new one; she should be ok.