How to identify Daphnia in any lake water ?
Question by cho: How to identify Daphnia in any lake water ?
I would like to grow live Daphnia in my home.(I live in the southern part of INDIA.We mostly have a tropical climate!) I need to see,how a daphnia would like in a pond/lake water.When i googled for Daphnia(or in Youtube) i always get the magnified image of it.
I need to know its real size in any natural water source,so that i can identify it in my nearby pond/lake and raise it on my own.I would really appreciate the help,if someone could give a link of a video in which,i can see the actual size of Daphnia.
Feel free to answer in the comment section below
One Response to How to identify Daphnia in any lake water ?
Leave a Reply
They’re magnified for a reason – they’re tiny! They can vary a little in their size by species, but in general, you’re talking about an organism that usually under 1mm, and may are only about half that. To really see them, you’d have to collect some of the water from a pond/lake in a clear plastic or glass bottle or jar, then look at them through the side to see them with the naked eye.
You can distinguish Daphnia (or Moina, a similar crustacean) from some other pond organisms just by the way they move – they jerk up and down as they swim. Like if they were moving left to right, their movement would follow this pattern: /|/|/|/| where they would go up and in the direction they were traveling, then sink before they move forward and upward again. The structures to the sides of their bodies that they use for swimming aren’t very efficient at forward motion, but they can move fast enough if they are threatened with capture – I can speak from experience trying to capture them in a 1 gallon jar with a turkey baster (I keep a live culture going for some of my fish, it’s cheap food if you start with a clean culture). Cyclops and Ostracods (about the same size) don’t move in the same manner. Of course, you’ll already have an idea of what they look like if you’ve done some image searches. Cyclops have a single “eye”, not two. Ostracods have a bivalve shell over their bodies and all you see of them are their legs and antennae.
To keep them, all I use is an air pump with a gang valve. They don’t like a lot of water movement, so keep the rate that the bubbles come out of the tubing slow enough that you can count the individual bubbles (about 1 per second). They’ll eat yeast or single-celled algae which I also culture. My culture can clear the water of a turkey baster full of concentrated algae in about a day. And you do have to do water changes on their culture, just like you would a fish tank. I take the water out when I harvest the Daphnia, and fill it back up as I add the algae culture. Put a little sand with crush coral on the bottom for some calcium to make their shells. And don’t siphon out all of the sediment that builds up, there will be Daphnia eggs in it. Which is good if anything ever happens to the culture – just keep the air pump going and the eggs will eventually hatch into more Daphnia.
An if you’re using them to feed fish, be careful at first. Ponds containing Daphnia may also have fish parasites in them, and you don’t want to introduce these to an aquarium or pond with fish. If you just want to keep them because you think theye interesting, that doesn’t matter as much.
topaz
February 6, 2013 at 12:52 pm