Tuesday, September 30, 2014

No end to mysteries

I do routine maintenance on the aquarium, daily, and half the time, it seems that I have to say, "What on earth is that?"

Last week I emptied the tank, washed the sand, and replaced everything. As usual, I kept out the dirty water I'd washed the sand with, and let it sit overnight, just in case any tiny snails were hidden in the gunk. Normally, the dirt settles, and the snails climb to the top, where I catch them and return them to the tank, then dump the goopy mess.

But this time, there was a white network of fibers just on top of the settled gunk, below the inch or two of clear water. I stirred the water again, and let it sit. Two hours later, there was the net again. Three times I stirred it; every time, white lines made a road map along the top two hours later.

Monday evening

I looked at the clumps under the microscope: all I could see were tiny, straight threads. Watching one for a while, I could see it grow, lengthening at both ends. When I stirred the mix, I could still see shreds of threads, unconnected. But two hours later, there was the network again.

Monday evening, overview. The bowl is 6 inches across. This is about a 3 inch section.

I was gone for a day, and came back Wednesday afternoon. Part of the bowl was covered with a papery coat; the rest was still clumps of threads, some still making a road map.

Wednesday afternoon

Zooming in, Wednesday afternoon.

The filled-in areas looked like papier-mache pulp; all short, white fibers, arranged every which way.

Thursday afternoon. The "roads" are gone, replaced by individual clumps.

I looked at several of these clean clumps under the microscope. There was nothing to see but the white fibers, still short and straight, sticking out in all directions.

Zooming in. Nothing but white fibers on the dark background.

Over the weekend, the threads covered the whole area, without any organization into clumps or roads. When I shook the bowl Sunday night and again this morning, they disappeared, and returned in a couple of hours to the final, uniform covering. No roads, no clumps.

I don't even know where to start to find out what this was.

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Saturday, September 27, 2014

Experimental aquarium photos

Taking photos of tank residents, I'm usually restricted to the first half inch or so on the other side of the glass. Beyond that, seaweed and swimmers, bubbles and shadows all get in the way. And there are already the scratches and algae on the glass itself to contend with. The photos are blurry, noisy, and dark, mostly unusable.

But the other day, I jammed the lens right up against the glass, ignored the obstructions, and aimed deep into the water. Here are the results, with just cropping and light level adjustment; I reduced the noise minimally, or not at all on some, in order to keep more of the detail.

The hermits love to climb into the anemone's mouth. They clean out detritus, and sometimes argue with her over a juicy shrimp. She doesn't seem to mind most of the time. This is one of the larger Hairy hermits, all pinkish from eating Violet Tunicates.

A smaller, blue hermit in a shell I brought from the pet store. There's a second hermit just behind a thin blade of red seaweed.

In the shadow of the eelgrass and sea lettuce.

A better view of Val's (the anemone's) side wall. I did smooth out most of the noise here, so distant detail is lost.

Farther back, two hermits on a dark brown, stumpy seaweed. The one in the orange whelk shell is a Grainy Hand hermit. No noise correction, no spot removal.

25 minutes later, a smaller Hairy hermit has climbed on top, for a better view.

A bit closer, on the side wall. An Asian mud snail and his reflection.

(I'm recovering from surgery, working slowly, as I can. All is well.)

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Thursday, September 25, 2014

The other white meat

When a flatworm catches a snail on rock or glass, the snail resists strongly, but the flatworm wraps itself around the shell and twists and tugs at it, sometimes for several hours until the snail tires. The flatworm always wins.

But a limpet should be different; there are no corners on its conical shell for the flatworm to get a grip on. So when a big flatworm oozed over one of my limpets, I never expected this:

You're wasting your time, flattie! He's stuck tight!

The flatworm tries to insinuate itself under the edges of the limpet, but it has a seamless hold on the glass.

Nothing much happened for 15 minutes. The flatworm slid back and forth over the limpet, never managing to get under the edge. Then ...

Suddenly, the flatworm shrinks inward and yanks up; the shell separates from the limpet meat.

The shell is pushed off to the side, and ...

The worm slides away, carrying a nice limpet steak. The shell remains, still attached to the glass.

Total time: 25 minutes.

The little white swimmers are copepods. The flatworm, and some of the limpets and hermits have a pinkish tinge this week; they've been eating Violet Tunicates growing on blades of eelgrass. Most of the tunicates are now just white scars.

I always blamed the hermits and the big anemone for empty limpet shells. Sometimes one loses its grip on a blade of eelgrass, or is knocked off by a hermit, and comes tumbling down to the sand or the anemone's mouth. On the sand, they are unprotected, and hermits and the crab eat them quickly.

Now, I've added flatworms to the list of predators. Poor, inoffensive, hard-working, glass-scrubbing limpets!

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Monday, September 22, 2014

Two-dimensional gluttons

It's flatworm season; every rock near the high tide line in Boundary Bay is hiding a few, plus their eggs. And tonight I found three babies in my tank. And a bunch of empty limpet shells. Baby flatworms are hungry!

"Hmmm! Looks like a tasty snail!"

Two skinny flatworms, several skinny smears of flatworm eggs, and a fat roll of bubble shell snail eggs.

And I've got a flatworm story to tell, as soon as I can. (I'm still, supposedly, on a break from blogging. But medical procedures are all hurry, hurry, hurry ... wait. Today, I'm waiting. Tomorrow I hurry.)

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Friday, September 19, 2014

Moss on a wall

In Burns Bog.



I'll be taking a short semi-break from blogging for a week or two while I deal with some medical issues. (Nothing to worry about.) I may post a few photos when I find time.

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Thursday, September 18, 2014

IRFD update: lizard, fossil, more!

Here are another seven happy Rock Flippers, who posted on Twitter at #rockflip:


Michael ‏@akmrbaldwin
Happy Int'l Rock Flipping Day from Alaska - a carabid beetle! #rockflip #IAmANaturalist pic.twitter.com/C7IrrL6n0D

Lobo GuarĂ¡ ‏@juandoso
Hidden treasures! pic.twitter.com/UcvzHVJqGs

Rebecca Zarazan Dunn ‏@rebeccazdunn
Happy International Rock Flipping Day  pic.twitter.com/8vGF2abNuF

Janet K C ‏@jkricketc
Just the usual dinosaur AKA Western fence lizard. pic.twitter.com/oQRg4kmJEZ

Jesse Calhoun Bethea ‏@jesscalhoun
Adventuring in Glen Echo Ravine for #rockflip day. pic.twitter.com/0UhD9xSbAL
Melissa found a fossil. pic.twitter.com/r5GEIpqYFx
Earthworm pic.twitter.com/h2BQHK4xTH

Catherine Scott ‏@Cataranea
Happy international rock flipping day! Perhaps you might find a beautiful spider! [photo by @Ibycter] pic.twitter.com/U3XHWoph7j

Laura ‏@lkwagonlander
September 14, 2014 http://pic-collage.com/_r4br8K49 pic.twitter.com/l2YpKZ6CIO
(This has a Rock-flipping kid.)

A couple of others also posted their photos on Twitter, but they had also added them to the Flickr pool, so they're on the first list, which I'll repost here:

Over in the International Rock Flipping Day Flickr group, many more interesting things have been discovered:

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Of two-tailed bugs, absent salamanders, and flipped rocks

Well, we've gone out and flipped our rocks (or not - one of us cheated took an alternate approach.)



It has been a quiet year, probably because I forgot last year, and we lost momentum. In spite of that, we made some interesting finds.

VERY IMPORTANT UPDATE: I just checked Twitter; there are a bunch more Rock Flippers over there. I'll add them to the list in a new post.

Here is the lineup, as it is now, copied from Heather's blog, At the Edge of the Ordinary:


Over in the International Rock Flipping Day Flickr group, many more interesting things have been discovered:

And this was a handy tip: Heather had found a pillbug under one of her rocks. "Or maybe a sowbug," she said; she finds them confusing. So do I, unless I pick them up; pillbugs roll themselves into a ball; sowbugs don't. (Here's a sample pillbug.)

But Sara Rall, in the comments on Heather's post, gave us a quick way to tell the difference, even from a photo.

To tell a pill bug (which can roll up) from a sowbug (which can’t), look at the back end. If it has two “tails” that stick out you have a sowbug (which would be my guess in the photo, but I can’t really see well enough to be certain).

Here's a family of sowbugs I found under a paving stone next door:

"Two-tailed" woodlice, aka sowbugs.

Zooming in. See the tails?

BugGuide has a photo of pillbugs side-by-side with a sowbug for comparison.

Thanks, Sara!

As usual, there were a couple or more Rock Flippers who did the "work" but didn't pass on their findings. If you're one of them, either Heather or I would be happy to add your name to the list; just give us a shout.

And many thanks to Heather for hosting this year. And I hope it rains soon and she finds a salamander; she well deserves it!

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Tuesday, September 16, 2014

Smiley

Douglas squirrel, Bear Creek Park:


"Chip, chip, chip, chip . . . " 

He called us into the forested area, chip, chip, chipping away constantly. Never stopped the whole time we looked for him high in the tree, nor while 4 people surrounded the tree taking photos. Never attempted to hide or leave. And smiled the whole time!

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Monday, September 15, 2014

Dem dry stones



Cougar Creek drains from the clay soils near our house, seeps under a couple of malls, meanders over to Cougar Creek Park with its lagoons and beaver dams, and plunges into a steep canyon. At the bottom end, it tunnels under the road into Sunshine Hills, and out into the Burns Bog flats.

We started our rock flipping excursion from that road, heading upstream, at first, into the canyon.

Reflections of the trees at the top of the Canyon. This year, the creek is shallow and slow.

Dying alder leaves and shadows of horsetails on the stones along the river bank.

We turned over many stones, both on the banks, and in the dry areas of the creek bed. Under a few, we found pillbugs, and one earthworm. Nothing more; the ground was dry, the creek bed scoured clean, and barely damp.

Where the creek was slightly deeper, held back by sticks and leaves caught on a few rocks, I turned over a rock, saw something flashing in the current, and caught it. I spread it out on the next rock to examine it.

A gruesome find. A red dragonfly, minus most of the head and abdomen, probably eaten by fish. The wings are intact. Nothing there to interest a hungry trout.

We crossed the road into Burns Bog. This part of the bog was once extensively mined for peat, and is criss-crossed by walls and railway tracks. A large part of it was paved over, but the pavement is cracked and mossy, buckling as the ground has heaved under it. Alders and maples grow in the gaps.

Moss breaking pavement, making soil for larger plants.

Cracked pavement. I looked in the cracks; nothing was moving.

It's been a dry summer; even in the shade, the moss was dry and scratchy. The ground underneath was no damper. We turned over many rocks and chunks of broken concrete, finding mostly dry soil, baked hard.

Under one slab of concrete, a few reddish ants had dug tunnels. They have something damp and bluish in the upper centre here; some sort of dead critter.

The underside of a paving stone. Ant trails, hot and crispy. No ants in sight.

Pillbugs

And a small, sleeping slug. I have never seen one before with a spotted white face; I didn't know there were such critters.

And this I will never understand: Burns Bog is supposed to be an ecological preserve, even this once-mined area. Access is mostly on foot, and the trails are long. Why, then, do people haul garbage deep into the woods here? On foot, carrying heavy trash, when we have door-to-door pickup or easily available bins?

Every time, we find something. Bottles and buckets, bicycle parts, grocery store trolleys, old cabinet TVs, rotting mattresses, shoes . . . This time, it was electronics. Underneath the chunks of concrete.

TV? Or what?

And what is this? It's plastic, backed with cardboard.

This I do understand. There's a graffiti'd wall just beyond.


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Sunday, September 14, 2014

Neon waters

A good place to hunt rocks:

Cougar Creek, in September colours.


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Saturday, September 13, 2014

It's tomorrow!

International Rock Flipping Day, that is.

Here's a handy badge for your blog. (Copy, save, and paste.)

We're looking forward to a good turnout this year; I hope you'll be joining us.

A quick reminder: if you've flipped rocks before, you know the drill. If not, here's what we'll be doing, from our host this year, Heather at "At the Edge of the Ordinary".

  • Find a rock. Sometime around September 14, flip it over and record what you discover. You can flip more than one rock.
  • You can record your findings in whatever way you prefer, whether that is through photos, videos, sketches, prose, or poetry.
  • Share your findings in a blog post (and use the badge at the beginning of this post, if you like), or upload your photos to this Flickr group.
  • ... I will collect all of your IRFD links and post them here for everyone to explore. You can then share them on your blog or social media (the hashtag on Twitter is #rockflip).

I (that's me, Susannah) will be monitoring the Flickr group, and will pass on the links to Heather.

Sunday is the Day itself, but it's ok to jump the gun if Sunday is impossible for you. I, for one, will be home expecting company all day Sunday, so we're heading to Cougar Canyon this afternoon to find some good rocks.

A likely-looking rock, at Boundary Bay.

And remember: be safe*, be respectful**, and have fun!

*One thing I (Dave Bonta) forgot to do in the initial post is to caution people about flipping rocks in poisonous snake or scorpion habitat. In that case, I’d suggest wearing gloves and/or using a pry bar — or simply finding somewhere else to do your flipping. Please do not disturb any known rattlesnake shelters if you don’t plan on replacing the rocks exactly as you found them. Timber rattlesnakes, like many other adult herps, are very site-loyal, and can die if their homes are destroyed. Also, don’t play with spiders. If you disturb an adjacent hornet nest (hey, it’s possible), run like hell. But be sure to have someone standing by to get it all on film!
**The animals we find under rocks are at home; they rest there, sleep there, raise their families there. Then we come along and take off the roof, so please remember to replace it carefully. Try not to squish the residents; move them aside if they're big enough; they'll run back as soon as their rock is back in place.



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Friday, September 12, 2014

A never-ending supply

Val, the big burrowing anemone eats snails. Eats them and spits out the shells for the hermit crabs to wear. Or glues them to her column.

But it's not just any snail that she likes; she prefers the upper intertidal periwinkles that climb to the top of the tank and occasionally drop straight into her mouth. One gulp, and they're gone.

She'll reject the Asian mud snails, as if the longer, sharper shell gets stuck in her throat. Or maybe she just doesn't like the taste.

And I've never seen her eat a little Nassa, but somehow there's always a supply of new empty shells; she must nibble on them at night, when I'm not watching.  And somehow, although I don't bring Nassas home with me, when I clean out the tank, I find dozens of these snails plowing through the sand. They're breeding here.

The Japanese Nassa, Nassarius fraterculus.

I've watched them mating often; one snail chases down another. When he catches up, there's a quick writhing and twisting interaction, and then they both hurry away. I've never seen their eggs; they lay them in the sand, in small capsules containing two or three eggs each, and the juveniles are as small as the sand grains. (Here's a video of mating Nassas, the eggs, and emerging juveniles.)

The recent pump disaster didn't seem to worry them at all; they're as active and numerous as ever.

This may be Nassarius fostatus. Or maybe not.



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Thursday, September 11, 2014

Baby pics!

I've been checking those Leafy Hornmouth egg cases in the aquarium every few hours this week, and finally this afternoon, I saw a dark speck on top. Very tiny; it looked more like a speck of dust, and I left it there. This evening, there were three specks. I fished them out with a paintbrush and looked at them under the microscope, because they were too small to see clearly with only the hand lens.

They are baby snails, still carrying what looks like a bit of yolk, but ready to go out into the wide world.

The egg case is 1 cm. long; the baby snail is about 2.5 mm.

Stretching to turn itself over. I had just returned it to the tank, upside-down.

Two of the babies, out of the tank.

Now, three hours later, another four have emerged, and there are several in the "birth canals", the pointed top ends of the egg cases. More are waiting inside.

The first three have gone on their ways. I don't see them anywhere;it's a big, busy tank, with many hiding places. And many dangers. I hope they have found safe havens.

And meanwhile, Ma and Pa are down on the bottom of the tank, pigging out on a rock full of barnacles that I brought them this Monday.

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Wednesday, September 10, 2014

Babies, babies!

The snails are hatching! Three are out and exploring their new home, already!

I'll have photos asap.

Couldn't wait to crow!

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Wings and sails

Boundary Bay, Monday.

Heading out for the afternoon

Heading North for the winter end of summer.*

It's that time of year again. Three or four V's of geese flew overhead, all going North, in the short time we were on the beach.

Update: From Cornell:
Even members of "resident" populations, which do not migrate southward in winter, will move north in late summer to molt.

Back to the tank inventory tomorrow; more prolific snails.

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Tuesday, September 09, 2014

Reconsidering

A couple of years ago, faced with snail egg capsules and an infant snail found with them, I tentatively identified them (with help from commenters here) as one of the rock snails, aka murex snails or Muricidae. I thought they were probably Trophonopsis orpheus, or another of the trophons. These prey on barnacles or mussels and other bivalves, and seemed to match some barnacle-eaters I'd had previously in the aquarium.

The hatchling, only a few millimetres long.

There were problems with the id; some references called it a subtidal snail, living at depths up to 180 feet. But I had found these in the upper intertidal zone. In Marine Life of the Pacific Northwest, it was the only rock snail that matched the snails I found, but again, it was supposed to be subtidal.

So every time I find another of these, or mention them, I spend some time reviewing the websites and books, looking for a closer match, a snail that fits everything I'm seeing in my tank.

And now, having the egg cases at hand, and confirming that these snails do, in fact, lay these eggs, I think I've been mistaken; that they are no trophons, after all.

Look at these egg cases. (Copyrighted, so you'll have to go there to see them. Here's the page; scroll to the second species.)

Now look at these, from my tank.

Tillie's eggs. A good match.

These are from the Leafy Hornmouth, Ceratostoma foliatum. This is another Muricid (rock or murex snail) that lives in the intertidal zone, but almost all the photos I find are of the full-grown adults; in these, the ribs are prominent, "leafy". The younger ones are like those in my tank.

This is fairly common to find intertidally.  The juveniles exhibit crosshatch sculpturing.  The axial ribs grow to large flares as it matures.  The adults may be plain white to purplish and may be striped.  At the base of the aperture there is a projecting tooth.  It lays a distinctive egg case. (From PNWSC.)

The Wallawalla.edu page adds more details: the siphonal tube of the Leafy Hornmouth is closed along its length, opening again at the tip. And the foot is a mottled cream colour.

(The siphonal canal of Trophonopsis is open.)

This is the youngest one in my tank, still quite small. The siphonal canal is completely fused along its length. The tooth is only visible from this angle as a slightly whiter spot. The shell is white with purplish stripes.

Here's the tooth, looking from the side.

Tillie, laying her eggs. The siphonal canal is closed, the tooth is near the entrance to the canal, and the flesh is a mottled creamy colour.

Down at the beach this afternoon, just below the high tide line, I was turning over rocks, looking at flatworms and a variety of eggs and egg cases. On one stone, I found several clumps of freshly-laid egg cases to match the ones at home. And there were the snails; some laying eggs, some eating barnacles. I turned each one over. Every one had the closed siphonal canal and the tooth.

Snail on rock, stony section of upper intertidal zone, Boundary Bay.

One snail in my tank looks like these, (but cleaner) but is much smaller. And its siphonal canal is open. It has no tooth. It's the oddball. Or it's too young to have developed yet. We'll see.

But. There's always a but.

On the Wallawalla.edu page, I see this:
Depth Range:  Low intertidal zone and subtidal to 60 m.
Habitat:  Found on rocky faces near barnacles and bivalves.  Avoids sand and mud. Most common in areas of strong surf ...
So I'm still not totally convinced; maybe other snails have the same egg cases, the same tooth, and the closed canal. I want to see if Mike and Tillie and their companion develop those big leafy wings as they grow larger. I'll keep on studying the reference sites and books until then.

What do you think?



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