Friday, February 22, 2013

Midges From The Sand Spring, Part Two

Meet a midge that hatched from the sand-spring!
 Now, I know this chironomid midge looks like a well-trained pet since it is posing nicely and waving amicably to the camera...
female chironomid midge from a spring-stream
... however, it is just doing what chironomid midges do... they habitually raise their long forelegs and wave them around.
   I brought home some sand and such from the bottom of the spring and placed this "stuff" in an aquarium for observation.  Soon some midge pupae began to hatch. 
midge pupa about to hatch

This photo shows a pupa a second before the midge began to emerge.
midge pupa ready to hatch
 Here comes a brand new midge!
midge pupa hatching
 What a moment to witness!
midge emerging from pupa

   The boiling-sand spring (which I've been posting about) is populated, among many other things, by many tube-dwelling midge larvae.  I'm assuming the midges that hatched came from these sand-tubes, because they are so abundant and I have seen very few other midge larvae in my aquarium.
chironomid midge larva in sand-tube
Here are photos of a midge larva that I coaxed from its sand-particle dwelling.
midge larva or bloodworm

chironomid midge larva or bloodworm
Some midge larvae get the name, bloodworms, because of their reddish color.
Here is a photo of a midge larva with a sand-tube in the background.
tube-dwelling midge larva
These midge larvae seem to be workaholics.  You'll see why I think that when you compare the size of a midge to its sand-tube dwelling.  The midge larvae are really serious about tube-making.
midge larva and sand tube
This midge larva measured less than 1/4 inch long while the tube was almost two inches.
That's alot of gluing sand particles together with salivary secretions. 

   Here are a few photos of midge larvae building their tubes with grains of sand and other particles that they gather from their aquatic environment.
midge larvae from spring-stream
They stretch out of the mouth of their tubes and grasp pieces of sand.
midge larvae building sand-tubes
They pull back in with some particles and cement the pieces of sand on the leading edge of their tubes.
tube-dwelling midge larvae

  I gather these particular midge larvae feed on detritus ... I've seen them act like they are feeding on leaf fragments as in the picture below.
The midge larva in the photo below was working a long time on the leaf fragment it has pulled into the mouth of its tube.
protruding midge larva tube
Notice how that midge's tube protrudes from the sand?
Here are a few more tubes that do the same.
   We did an experiment to see if these protruding tubes have a higher occupancy rate than the tubes scattered on the surface... like the ones in the photo below,  or the tubes from thick hash in the second photo.  We were surprised at what we found... The protruding larval tubes had only about a 10% occupancy which was the same as the light colored tubes scattered on the sandy bottom of the spring.
midge larvae tubes
However, the darker colored tubes from the thick hash had a 60% occupancy rate.  Perhaps the reason for the difference is the species of midge, or perhaps the abandoned tubes have been transported  from the "sweet spots" by the spring's current.
midge larvae tubes
These heaps of midge larvae tubes occur right near the head of the spring... on the left side of the photo below.
Boiling-sand spring
   My taking a few handfuls of "stuff" from the bottom of this spring and placing that "stuff' in an aquarium indoors may have sped up the midges' clocks... for their hatching this time of year seems unnatural.  However, my indoor midge hatchery gave me the opportunity to show more of what transpires in this obscure little spring even if it is winter time.
There is one slight little problem...
Male midge with feathery antennae midges like to fly to the windows because, well, they are flies and...
male midge
...they want out ... problem is,  it's still winter outside.

By the way, the scuds are still very active in the sand-spring so I suspect they'll be up next on Nature Posts.

Monday, February 18, 2013

Midges From The Sand-Spring

Meet a midge from the sand-spring!
Female chironomid midge from a sand-spring 
My boiling-sand spring contains innumerable sand tubes from the larvae of chironomid midges.
tubes of chironomid midge larvae in a sand-spring
These chironomid midge larvae live in retreats, or tubes, they construct from sand and other particles.
Chironomid midge larva building sand tube
I'll post more details about the midges and their larvae in my next post.
   Here is a photo of a midge pupa that is ready to hatch.  It wiggled, or whipped, in a manner similar to a mosquito larva, in order to maneuver through the water and rise to the surface.
Chironomid midge pupa about to hatch
 Notice how the legs each have their own sheath and how they are neatly looped under the wings.
Chironomid midge pupa ready to hatch
Shortly after surfacing, a small miracle happens...  the midge somehow hits the "eject button" and emerges from its pupal case and from the water-world without becoming caught in the surface film.
amazing moment of a midge hatch
 Only seconds earlier this midge was an aquatic insect from a sand-tube on the spring-stream bottom.  The emergent adult midge can fly away almost immediately.
  The pupal skin is still trailing this freshly emerged female chironomid midge.
freshly emerged midge with pupal skin

   Here is a photo of a male midge and his feathery antennae.  Note the typical chironomid midge stance of raised forelegs.  Oh, and I have the midge on my index finger to give an indication of its small size.
male chironomid midge from sand-spring
Wouldn't you agree that these chironomid midges and their tube-dwelling larvae are worthy of another Nature Post? 

Friday, February 15, 2013

Spring-dwelling Snail Antics

   Freshwater snails populate the boiling-sand spring that I've been posting about recently.  As the snails graze on the biofilms growing on the spring's substrate, they perform some antics that we've enjoyed watching.
freshwater snail
   One thing we've seen is the snails taking turns in a "rock tumbler".  In the photo below, two snails (in the upper left) are crawling on the edge of a sand-boil, while the two snails (near the center of the photo) are tumbling repeatedly in one of the turbulent micro-volcanos of sand.  Perhaps the snails were accidentally entrained in the surging fountain of sand, or perhaps they did it for fun like the scuds that seem to enjoy surfing in the sand-boils..
snails in boiling-sand springs

   Your author has also engaged in some antics at the spring in order to capture some of these photos of aquatic life... one such antic was kneeling in the spring on a mid-winter day.
Another was weighting down an aquarium to provide a window into the underwater world without the glare. The "sunken window" allowed me to place my Nikon underwater for some macro photos of freshwater aquatic life.
I also took some pictures of the spring's aquatic life by putting some of the stream substrate into the aquarium for observation.
  Here is a photo of an aquatic snail grazing on algae that has colonized the aquarium glass.
freshwater snail scraping algae

   Here is a view into a snail's mouth as it feeds on algae.  We could see the snail's radula as it scraped away against the glass.  The radula is the horseshoe-shaped whitish area.  If you look closely you can see many lines like teeth on a file.  These lines on the radula are rows of many minute teeth which act as a rake, or rasp, to loosen particles of food material.
freshwater snail mouth with radula exposed

   When I snapped this photo of a grazing snail, it was approaching a resting cyclops...coincidentally,  this made the snail look as if it is going to swallow the unsuspecting cyclops.

   Another antic of the snails is crawling upside down under the underside of the surface-film of the water as they feed on floating algae.
snail crawling on underside of water surface

   Another spectacle we have seen is the snails performing a slow, gracefully glide down through the water to reach the bottom.  The snails appear to be "diving" at a blissfully slow rate, when actually they are descending at a snail's pace on a thin line of slime.
"diving" snail descending slime trace
Although the slime line is hard to see, I've demonstrated its presence by gently reaching into the water and towing the snails around by their invisible "rope".  
aquatic snail descending slime "rope"

In the photo below, the rope of slime is barely visible down the center of the picture... it looks like a thin strand of spider silk.  In this instance the slime line was preexisting for it continues below the descending snail.
freshwater snail descending slime trace

Here is a photo of a snail ascending a slime rope.  The line isn't visible but its effects are... see the depression on the water's surface from the pull of the snail's weight on the line?
aquatic snail climbing slime trace

That's all I have about the snails... for now.
freshwster snail and cyclops
   Our sand-spring still has plenty of interesting aquatic life to post about... like that cyclops that has its eye on me.  I may need other equipment for those small things ... equipment that can turn a drop of water into a zoo. 
  Next is a post about the chironomid midges and their tube-dwelling larvae that inhabit the sand-spring.

Monday, February 11, 2013

Appearances Can Be Deceiving

Whatcha' don't see through a macro lens... Tee-hee-hee
  What is manifest to the eye may not be factually valid.

Shouldn't aquatic snails avoid the appearance of evil?

Saturday, February 9, 2013

A Spring Of Life In A Winter Woods, Part Two

  Right in the midst of the silent forest - a forest muffled by snow and shut down by the cold - this boiling-sand spring is bustling with activity.
Boiling-sand spring in a snowy woods
   The liveliest things in the spring are the miniature underwater fountains of "boiling sand".   The spring water surfaces through loose sand at the head of the spring and makes these ever-changing sand boils.
underwater sand boils in a boiling-sand spring

 While watching the sand "boil", it doesn't take long before you notice the amphipods  - active little crustaceans - commonly called scuds.  The scuds are continuously zipping around exploring the spring.  Here is a photo of a scud peeking around the vein of a leaf.
scud or amphipod from a spring
This photo of a scud shows a typical position... and, no, it's not dead... scuds commonly rest on their sides.
scuds are side-swimmers
Scuds are called side-swimmers, for good reason, as they often swim that way.  The scuds can also scurry around the substrate on their sides.
scuds are sideswimmers
In fact, the scuds seem very comfortable in almost any orientation...vertical, horizontal, or even upside-down.
scuds are omnivorous

With all their exploring, scuds are sure to encounter other aquatic creatures.
caddisfly larvae
   Some common aquatic insects in these headwaters are caddisfly larvae.  These particular caddisfly larvae construct tubes of what look like pieces of bark and perhaps some pieces of coal.
caddisfly larvae with bark-fragment tubes
The caddisfly larvae that populate our boiling-spring are of the shredder variety.
caddisfly larva eating leaves
They eat leaves... from what I could see.  Fallen leaves that are decomposing and are microbially conditioned with bacteria, fungi, and diatoms.
caddisfly larva feeding on leaves

   Another very common critter in this winter-bound spring is a small, free-living flatworm called a planaria.  Here is a photo of planarias thronging the sand boils
planaria in a spring
I wonder if they are feeding on small organisms around the sand boils or are they simply attracted to the current?
   These flat, black worms have eye-spots and sensory organs on their heads which give them a unique look and make them interesting to watch...
... as they glide along with cilia-powered motion aided by a secreted roadbed of slime.
  I mentioned larval Northern Spring Salamanders in my introductory post.  Here is a photo of a salamander larva that seems to be playing in a sand boil.  Perhaps it enjoys being sand-blasted.
Larval Northern Spring Salamander living in spring during winter
   This next photo shows the salamander's external gills which are part of the aquatic stage of many salamander's life cycles.   I should qualify my identification of these salamander larvae... it's based solely on their resemblance to the Northern Spring Salamanders I've seen crossing the road.
salamander larva with external gills
   Notice the small size of this salamander larva. In the picture below, there is a cloud of sand spewing from a sand boil... grains of sand are sprinkling down on the salamander and they give some scale to the photo.  Also, on the left among the organic debris circling the sand boil, there is a scud which would measure about 1/4 of an inch.  Without measuring, I would say the salamander was about 1 1/2 to 2 inches long.
Norther Spring Salamander in a boiling-sand spring during the winter

 I could keep going with this overview of the aquatic life in my little winter-bound spring.  As an example... there are a few things in this frame of this one photo that I haven't covered yet.
   The lower arrow points to a tiny red head of a blood worm - a tube-building chironomid larva.  The upper arrow points to a very small caddisfly larva with a tube of small, white, sand-grains.  That minute caddisfly larva is crawling on one of the tubes of the chironomids.  The blurry white flecks in the background are copepods and other microorganisms swimming in the water.
   This post was an overview of some of the most obvious and active spring-dwellers.  What fun to look at this thriving aquatic community!  Trust me... we're only started looking what lives in this spring during the winter.
    Oh, and I didn't get a chance yet to post about the scuds that go surfing in the roiling, boiling, sand fountains.  I'll get around to that soon, and I'll post about some additional inhabitants of this boiling-sand spring such as the aquatic snails.  I might also look at some of them in-depth, if I don't get side-tracked by the Rhododendron or by galls on the saplings.