Those microscopic crustaceans that are a “must have” for a pond program we do using a Micro projector and invariably take hours to find. This even though they are said to be coating the world in multiple billions. In fresh water, salt water, frozen water, for crying out loud. Just never in our particular pond. Well that’s not true. They are there, clogging the waterways when you don’t need them, but try and produce a half dozen for a class and I can guarantee they will be MIA.
If you were reading this last year, I do believe I filled you in on the life and times of the Cyclops variety of copepod. The one I am after, a hunter itself, looks for things even smaller to ingest. And what I really hope to find is a female with her “saddle bags” of eggs attached right above her abdomen like two grape clusters.
Now there are some 400 kinds of Cyclops species but I will settle for any one of them. The name refers to the one eye they seem to have right in the middle of their “head”, cephlathorax actually. Their jerky movement when swimming is what gives them away. Of course then; actually catching one in my pipette remains a challenge. However, hours later, a wee little group of them was finally found and I will just hold my breath that none of them “do themselves a harm” overnight in their container.
As I probably said last year too, the Daphnia are really the darlings of the show, what with their transparent bodies and a brood patch that 9 times out of 10 is full and looking as though birth were imminent-which it often is.
Life on the bottom of the food chain means you have better be a stellar reproducer, if you intend to stand the test of time-and they are. One source claims every 10 days, a new brood can be brought forth from spring through to the fall while another claimed it could happen in as few as three days. Let’s be conservative and believe 10. With each brood being between 8 –24 individuals, that creates a lot of daphnia to the delight of all those fish fry and damselfly nymphs that eat them. Also to scientific researchers who like to see the effect something has on an organism’s offspring. No need to wait forever with daphnia. I read they do research on the effect of alcohol and caffeine, which sounds too much like a Far Side cartoon to be fact, but if you believe everything you read in Wickipedia, then perhaps they do.
No doubt I told you they reproduce by parthenogenesis, but in the spirit of tradition let’s tell you again! It means they leave the dating picture out of things, their offspring are true clones of mom. And are all female themselves, leading to more cloned females when they reproduce. Again, if you are being gobbled up at a dizzying rate by other pond dwellers there is no time to find that special someone, so nature allows for this method. However, as fall comes on, and the need for eggs that may over winter occurs, the female will amazingly give birth to some males,
(how does that happen?!) and then the mated offspring will have a thicker shell that can last through the winter and as another benefit, it will get a shot at some different chromosomes; always a good thing for variety sake.
Today plenty of daphnia were on hand. Tomorrow I will cross my fingers for a birth in the class. Under the microscope, which is somehow always unforgettable. One minute a brooding mom, next a screen swimming with little mom look-a-likes. By the way, the Cyclops larva looks nothing like the adult but most molt a few times to get that classic Cyclops look. Looks more like a splatted crab than a copepod.
Well perhaps you have heard this all before. But I realize now, it has become a spring tradition so why not include it? The path I walk through the woods is every day more carpeted by Canada Mayflower, also a tradition. The swans are chasing the geese off the pond at work with great flapping and honking and swan like hysteria, another tradition. The Oriole has returned to its trees, right on time, as the early cherries begin to bloom and Catbirds are mimicking and mumbling in my front bush again. May your spring traditions be taking place like clockwork wherever you are. Noted and appreciated, from hunting copepods to hanging out the hummingbird feeder the season is fully upon us. Now let us enjoy!
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