Crawmom

I was looking into one of the creek pools when I noticed a crayfish slowly moving along the edge of a flat rock.  It’s not often that you see crayfish in the open sunlight, so I took a seat on the creek bank and waited to see what it was going to do.

My grandfather told me that crayfish were properly called crawdads, but when I noticed eggs beneath the tail section, I had to consider this individual to be a crawmom. 

Her foraging gradually brought her out into the open.  She seemed to be feeding on bits of material scraped from the rock.  It appears that her eggs have recently hatched.

Female crayfish carry their eggs among the swimmerets located beneath their tail.  After hatching, the young remain in place until they reach the point of development where they can survive on their own.

I didn’t want to prematurely dislodge the youngsters, so I didn’t pick her up.  When I left, she was still busily grazing the rocks.

Hidden Picture

I flipped a rock in the creek in hopes of finding a salamander larva and I was not disappointed. As is my custom, I snapped a shot as soon as the rock was clear so I would get some type of image, just in case my intended subject took off. As soon as this shot was taken, the larva zipped for cover beneath a large rock and my photo opportunity was over.

When I later checked my shots, I found that I had captured the larva, a Dusky Salamander, but water distortion and the reflection of the sky didn’t make it a very good picture.

Then I noticed something to the left of the larva and zoomed in to find a young crayfish. He’s got something held in his tiny pinchers, but I can’t see it well enough to get an ID.

So I decided to play the old Hidden Picture game I used to enjoy while in the orthodontists waiting room and see what else I could find. There are several Water Pennies in the shot. I like to see these because they are indicators of high quality creek water.

An aquatic isopod is grazing on a submerged stick. These scavengers feed on decaying plant and animal matter. I used to keep these as pets when I was a kid, because they were the closest thing I could find to a living trilobite. I’m always finding things in my photographs that I never saw in the field. It’s a lot of fun to discover these little surprises.

Other Creek Creatures

The creek, formerly a long single body, has now been fragmented into individual pools. This happens every year and it always makes me think of Darwin and his divergent finches. When water flow was high, the aquatic animals could move from pool to pool by swimming upstream or drifting downstream with the current. Now the organisms are trapped in their individual pools and their lives will interact only with others of like fate. Given many thousands of years, organisms from each pool could differentiate into a multitude of species. Of course, most of the pools will be dry in two months, so the possibility of new species is just an idle thought.

The larger pools contain abundant life. This small salamander larva still has plenty of area in which to hunt and hide. In order to survive, it must lose those gills and become an air breather before the pool disappears.

Crayfish stalk the pools looking for prey. As the pool shrinks, the prey becomes more concentrated and easier for the crayfish to capture. Shrinking pools also make it more difficult for the crayfish to escape from predators such as raccoons and herons that follow the creek and examine each pool for tasty morsels. When the water disappears, crayfish have the options of burrowing into the creek bed to await the rains or taking off overland in search of better living conditions.

When Water Striders find conditions not conducive to survival, they take shelter in protected areas near the creek. I found several wedged beneath flat stones in the creek bed, waiting for conditions to improve.

These pools are still receiving fresh water. There is a small flow moving down the creek channel, but it’s traveling through the gravel of the creek bed and is not noticeable except in the pools. Tiny pools such as this could persist for weeks if ground water levels stay high.

There are a lot of small insects trapped in the tiny pools. Dominant in this pool are young Water Striders, Riffle Bugs, Mayfly larvae and some type of fly larvae. If the pool had been large enough to support fish, most of these guys would have been gone.

If any of the insects do make it to flying adults, they’ll have to dodge this conveniently placed spider web. When emerging, many insects tend to come straight up from the water. Aquatic insect courtship activities often take place above the water in which the eggs are to be laid. For these reasons, some species of spiders habitually locate their webs above the water.