Today’s photos are a batch of microorganisms and small creatures sent in by reader Mary Rasmussen. Her captions and narrative are indented, and you can enlarge the photos by clicking on them.
If there’s water, there’s probably something living in it.
I collected a half gallon of water, muck, detritus, rocks, a tiny aquatic plant and 3 snails from some very shallow temporary pools along the Lake Michigan shore. Lake Michigan’s depth varies year-to-year. The pools sometimes last a few years and sometimes just a few weeks. This year the lake level was down and the pools dried up by the end of summer.
I put the water etc. in a 12 inch square glass aquarium with an L.E.D. light on top. These are the creatures living in the water that I was able to photograph.
The last 2 photos are Seed Shrimp that were living in 2 inches of water that had collected in a truck rut in a gravel road.
Aquatic Sowbugs (order: Isopoda) a freshwater crustacean, lived at the bottom of the tank, feeding on organic matter.
Two Hydra (phylum Cnidaria, class Hydrozoa, genus Hydra) After a month there were many of these predators in the tank. I could watch them for hours.
Hydra don’t show any signs of deteriorating with age, and there is speculation that they may be immortal. (I’m sorry but I can’t identify that creature on the left.)
Hydra with bud. The bud is a clone of the parent and will break free when mature.
A freshwater snail laid a trail of eggs on the aquarium wall. These are close to hatching.
Male Cyclops (Cyclops bicuspidatus), the dominant cyclopoid species in Lake Michigan has a single red eye.
Female Cyclops carrying two egg sacs.
Seed Shrimps (subphylum Crustacea, class Ostracoda) have a hard shell and use their antennae to move through the water. These were barely visible in the water of a truck rut.
I used a Nikon D500 camera with three off-camera flashes. For larger creatures (Sowbug, Hydra) I used a Nikkor 105mm macro lens with extension tubes. For smaller creatures (snail eggs, Cyclops, See Shrimp) I used a Laowa 25mm f/2.8 2.5-5X Ultra Macro lens with extension tubes.
Super photos. I wonder if the critter to the left of the hydra is a larva of the phantom midge (Chaoboridae).
That is a good idea. Maybe a rotifer?
And thanks Mark! I’ve got a lot to learn here.
Thanks Greg, I’ll look up the phantom midge!
Very cool. I used to collect water specimens from a nearby pond as a child to look for creatures under a microscope. Very few people have even heard of ostracods, but they are very common fossils. And they have an ancient origin, found all the way back to the Ordovician Period. Their small size and durable hard skills make them easy to preserve.
Thanks Norman, I literally stumbled into these. I had never heard of them before and certainly didn’t know they are common fossils!
I think that the mystery animal in the third photo is an aquatic oligochaete (earthworm) in the genus Chaetogaster.
Thanks Tom, I’ll learn about aquatic oligochaetes!
These are wonderful photos. Thank you.
The hydras are so pretty! It’s been a long time since I took a close look at some pond water—these pictures make me want to try it again.
Great creatures and photos. I love that male Cyclops with one red eye.
These are so cool! I think everyone should try this.
Fascinating stuff, Mary, thanks! This is the first time I’m learning about seed shrimps. The female cyclops with egg sacs is particularly good. Hydra sometimes grow in my rain barrels. Now I’ll have to pay more attention to them this summer.
Wow, these are brilliant. I love peering into mucky pools. But I can’t see this much detail with the naked eye.
I don’t think we’ve had a micro/macroscopic water creature RWP. These were terrific!
I have a turtle pond and a microscope and have enjoyed looking at the wee critters. I should look into getting a microscope that can take photos. Though you seem to be getting excellent shots with specialty lenses and extension tubes.
Nice experiment and photos!
In my teaching days (70s to 90s) I would collect plant material from a lake or stream, place in a bowl in the lab and put a white ice-cream container to float above the weeds. The Hydra would migrate to the container and settle there, It was then easy to transfer them to a petri dish for my pupils to observe under a binoc. Adding a few Daphnia (‘water fleas’) to the dish to watch the Hydra feed was a highlight for my young biologists.
Thanks for these excellent photos; they brought back some wonderful memories of my time in the classroom.
Thank you Don, this is a great idea that I will try!
Great photos & subjects! Enjoyed it!
Magnificent photos. Thank you.
Thank you everyone. This is my hobby–I’m still learning and your comments and input are most appreciated!
Hail hydra the scourge of the aquarium (along with planaria).