A size too small

Spider kids grow out of their clothes, too.

Young cellar spider's cast-off leggings and T-shirt, hung out to dry.

Immature spiders molt frequently; they've got a lot of growing to do, from pinprick spiderling size to fat adult. This one was about half-grown, a spider teen. Well-fed, so he grew out of the leggings while they were still new-looking.

To shed the old exoskeleton, the spider has to bust out from the inside. It increases its heart rate to pump a lot of hemolymph (the spider's blood) from the abdomen into the cephalothorax. The pressure expands the cephalothorax, which pushes on the old exoskeleton until it cracks. The spider flexes its muscles until the old exoskeleton falls away. (HowStuffWorks)

One of my crabs molted this morning, too; I found the old carapace and legs up against the glass. When I returned with the camera, after morning chores, it was gone. The hermit crabs collect these, break them up, and clean out any edible remains. The remaining chitin is eaten by bacteria; starfish and certain fish can also digest it.

I don't know what, if anything, eats old spider molts. Something must; in nature, nothing is ever wasted.

On a driftwood log

Three links in a food chain:

Clump of mushrooms growing out of a driftwood log.

Maybe four links: people felled the tree, possibly. Then the ocean carried it to Salmon Point and threw it onto the shore. Here, mushrooms are eating the wood. And something is enthusiastically eating the mushrooms; the bites look like those of slugs or snails.

I looked for the slugs, but they are usually night feeders, especially out in the open. I couldn't see any, nor any sleeping snails. The logs make good, sturdy roofs for slug bedrooms, down in the dark and damp.

Dotted line with eyes

I think I could spend a lifetime on one small area of our intertidal shelf, looking, looking more closely, and looking again, and never run out of something new to discover, And for each basic body plan, Ma Nature, who loves to tinker, has devised an almost infinite round of changes.

The latest critter I have found looks, at first glance, like an ironed amphipod. He has long, pointed antennae, a good collection of legs and other assorted limbs, a segmented body, prominent eyes. But he lies flat and swims in a straight line, which no self-respecting amphipod would ever do.

Tanaid, about 1/8 inch long

The last two collections of fuzzy eelgrass and clamshells from the tide flats carried dozens of these tiny beasties, all about the same size. Without a lens, they look like short dotted lines, with a darker dot at the front. ...o 

Side view. The antennae have a reddish spot halfway along their length.

I checked out all my references. I spent hours Googling. (Why, when asked for planktonic crustaceans, does Google give me umpteen photos of walruses?) I checked E-Fauna, for BC; there are 389 species of amphipods in their list, 75 species of isopods, very few with photos. But this is neither amphipod nor isopod, but something in between.

ASnailsOdyssey didn't have anything on these. They weren't in Beachwatchers. I finally found an image that led me to RealMonstrosities, and the Tanaids.  (But these aren't monstrosities at all; I think they're cute.)

Face view; breaking the surface of the water, and heading into the shadow of the camera. She didn't like the light.

Once I had a name for them, I did find some information.

There are more than 700 species of this family, several thousand of the larger order. (From Crustacea.net.)

In some areas their population size has frequently been measured at more than 10,000 individuals per square metre and, on occasion, over 100,000! In the abyssal plain they are often the most abundant crustacean and their numbers almost rival that of polychaetes. (From RealMonstrosities)

Most are very small, part of the almost invisible base of the food chain that starts with tiny swimmers and ends with us.

The abundance of tanaids is strong evidence of their ecological importance. Despite this, they have been neglected in most ecological surveys (Baldinger & Gable, 1996). This ecological ignorance of the Tanaidacea is caused by the immense difficulties associated with identifying these animals. (From Crustacea.net)

So I'm not sure of the species of these beasties. Nor of their lifestyle. Some families are tube-dwellers, others are free-living, some live in burrows. Some are filter feeders; others are predatory.

Some species are hermaphroditic. Others start out life as sexless neuters, then turn into females. After their final molt, they change into males, stop eating, reproduce, and die.

The males of many species have very large pincers, sometimes as long as the rest of the body. Here's a photo, taken on the west coast of Vancouver Island.

Dropped in my tank, the little dotted lines swam happily away to burrow into the fuzz on the eelgrass. A day later, after the hermits had eaten their fill of fuzz, there was no sign of them. A couple turned up in the filter when I cleaned it a week later; a temporary shelter for them, free from hungry hermits and dancing shrimp.

The honeydew eaters

Linden trees, says Wikipedia,

"... are subject to the attack of many insects."

It's all the trees' doing; the sap flows richly and freely in its veins, easily tapped into, nutrient-rich, sweet and fragrant. Aphids harvest it, and serve it up to a throng of other insects.

Linden tree branch, with yellow jacket

Aphids, varying ages, and a molted skin.

The aphids that feed on linden are the Eucallipterus tiliae, the Linden Aphid. The new hatchlings are white or pale green, red-eyed. They develop their characteristic dark spots and stripes as they go from molt to molt. Some adults are winged.*

The thing about aphids is that they eat more than they use, and "spill" the excess. (The proper word is "exude", and the honeydew they produce is an exudate.) The nectar coats the leaves, dripping from branch to branch; the leaves become sticky. Sometimes the whole tree glistens and sweet rain falls to the ground beneath, feeding a black fungus in the grass.

And so the food chain goes, from the lawn to the tree to the aphids, to the ants that farm them and the ladybugs that prey on them, to the horde of winged critters feasting on the lot, and back to the ground to start the next cycle.

Ant on a twig

I cheated: two sizes of ants run up and down the trunk, along the branches, across the leaves. Run and run and run and run. I was having trouble getting one where I could focus on it. So I mashed a raspberry with a bit of water and sugar, and painted a stripe around the trunk, where they couldn't miss it. Five minutes later, the large ones were lining up for the treat.

Dessert bar

Ladybugs don't wait for the aphids to produce honey. They take their juice "on the hoof", with fresh aphid meat.

Medium-sized ladybug larva. The orange deepens as they grow.

Younger larva.

And a nineteen-spot adult.

Of course there are always flies.

Very small fly, unidentified.

Accidental fly. I was chasing the yellow jacket, and didn't notice the silhouette of a common fly on the back side of a leaf until later.

There's a small mob of tiny biting black flies, rarely photographed because I'm so busy swatting them before they bite, and usually being too slow.

I don't know what's hiding under this silky tunnel. Probably a pupating moth.

The wasps - dozens of them as long as the sun shines - flit from leaf to leaf, sipping nectar off the leaf surfaces, and looking for a good home for their babies, inside a caterpillar or spider.

Black and yellow mud dauber, I think.

I caught this wasp with the butterfly net, and had to chill him to calm him down. He woke up almost as soon as I brought him out; within a minute he was on his feet and heading for the door. This photo catches him just stretching and yawning.

The female wasps will build a series of one-egg mud nests. With each egg, they will deposit a paralyzed spider, then plaster over the entrance. The larva will hatch and eat the still-living spider.

The orange wasp, again. She's a ichneumon wasp, Theronia atalantae fulvescens.

These wasps prey on several moths and butterflies, notably the pine butterfly, a relative of the cabbage white. I may have seen these about and mistaken them for cabbage whites; they are very similar. The wasp also takes tussock moths and tent caterpillars.

In all the time I spent examining the tree this year, dodging wasps the whole time, I saw only one spider, and one very small caterpillar. It looks like the wasp babies are well provided.

And a tiny wasp, unidentified. It may prey on the larvae and larva food of the larger wasps.

The bark is juicy, too. I don't know what makes these tooth marks. Squirrel, maybe? An ant in the lower right corner shows the size.

Lichen on a small branch. Just because.

*Last year's post about this same tree, with larger aphid pics, is here.

Underwater tug-of-war

"Waste not, want not," they always said. I took it to heart. While the nudibranches, Melibe leonina, were slowly dying in a bowl of clean sea water on my table, I noticed a few cerata, fin-like structures on the back of the sea slug, lying loose.

"In some nudibranchs, cerata are used as decoy tactics. Typically, these cerata are not armed with nematocysts, but when attacked, the nudibranch will autotomise or drop one or more of its cerata. The dropped cerata produce a sticky secretion and wriggle energetically for some time after being cast off, presumably causing a distraction and allowing the nudibranch to escape." Wikipedia

These weren't wriggling by the time I found them, but they did look interesting, almost like tiny slugs or flatworms themselves. I wondered if the crabs would eat them. I spooned up a couple and dropped them into the aquarium. A hermit crab snatched the first one from the water as it came down; a few seconds later, one of the crabs had dragged the second into its hole under a rock. Neither crab was planning to share.

I collected the rest of the cerata and dropped them in, one at a time. An anemone nabbed one, and closed in on it, so I nudged another in the direction of a larger anemone. Snatch, fold, gulp! It was gone in a few minutes and the column was bulging.

The barnacles didn't like them. One touched the net of the large black thatched acorn barnacle, and it closed down tightly and stayed that way all night.

The next day, I dropped in a dead nudibranch, entire, which started a sand-wrestling, claw-waving free-for-all. One small crab hid under the rock and pulled the whole nudibranch down after himself, but that wasn't to be permitted. Imagine a cat half-way standing on her head to reach that finger wriggling 'way down under the sofa cushions; put a shell on her, and you've got a hungry hermit after a hidden snack.

Later on, when I looked in, the remains of the nudibranch was spread out on the sand, with a circle of scavengers all working together on it. The next morning, it was gone entirely.

The other three Melibes died. I put them in the freezer. A couple of days ago, I floated a Melibe ice cube in the tank, and watched, camera in hand.

Hermit Rex grabbed it on its way down, again. But a second later, the Blue-clawed hermit scrambled over the rocks and clamped onto the other side. Both pulled back, stretching the flesh to its limit. Rex is bigger; he had the advantage, but he was trying to eat and tug at the same time. Blue got a good grip and yanked. Almost got it, but ... The tug-of-war lasted quite a while, while the other crabs and hermits lined up to watch and wait their chance.

They look like they're sharing here, but Rex is just trying for the advantage of height. The fringed edges of the hood are still entire. Blue is pulling on it; Rex has the thicker body.

Eventually, one lost his grip, and Snowflake, the white crab, dashed in and ripped a chunk off. The other hermits descended on the tattered remains. By morning, again, not a morsel was left.

Big Green, holding a tiny portion of leftovers.

Even the worms were involved. They are too timid to enter the fray, but sneak around the edges, looking for crumbs, retreating in a rush if a crab leg touches them. This one stretched out almost his full length, about 6 inches.

The snails are algae eaters; they weren't interested.

Periwinkle. Isn't he pretty?