Ostracoda is a class of the Crustacea, sometimes known as the seed shrimp because of their appearance. Some 65,000 species (13,000 of which are extant taxa) have been identified, grouped into several orders.
Ostracods are small crustaceans, typically around 1 millimetre (0.04 in) in size, but varying from 0.2 millimetres (0.008 in) to 30 mm (1.2 in) in the case of Gigantocypris. Their bodies are flattened from side to side and protected by a bivalve-
From 2 to 4 millimiters long, those seed shrimps (exact name not know to me) swimm actively during the day at any dept. The eggs have been bought on ebay and have been hatched in pure distilled water mixed 1:10 with battled water in a half liter container. It took from 3 to 10 days to see the small white dots swimming. When as big as 2 mm I moved them to the other acquariums. They lived around 30 days and apparently they did not reproduce. After 30 days microscopic white dots reappears. With 100 magnifying pocket microscope I identifyed them as seed shrimps.
Around 2 millimiters long, dark brown with beige spots they swim just under the surface all day upside down. Only rarely they can be found on the acquarium walls or on the bottom. They reprocued quite fast. I started with 3 of them, collected in a natural pool and after 2 months the surface of acquarium 2 and 3 was covered by tens of them.
Around 3 millimiters long, dark glossy grey with nice shades and a very curved banana shape. They only dwell on the bottom in the detritus and never move from it. I did not realize I collected it. After 1 month since I collected specimens this nice ostracod showed up and now there is a nice dozen showing up.
Around 3 millimiters long,rounded and nice orange/yellow color. Swims verywhere at pretty high speed, stationing on the glass walls, the acquarium moss and along the surface. Theyare extremely prolific and resilient. I collected a few of them, extremely small ones. After some weeks they where already multiplying and now hundreds swim in the acqurium. I trow a couple of them i a container in the garden filled with rain water adding food only occasionally. Now the container hosts hundreds.
UNIDENTIFIED BLACK OSTRACOD
Around 2 millimiters long, rounded and dark grey or black. Swims everywhere at pretty high speed mostly on the glass walls. I collected a few of them in park Josaphat. In the aquarium they reproduced a bit. In the garden pond where I trow some, now they are pretty well developed.
UNIDENTIFIED GREEN OSTRACOD
Very small ostracod. Discovered in a park in the middle of the city around middle September.Green, with an oddy arrow shape, between 1 and 2 mm long. They swarm togheter rather than swimming erraticly and mostly close to the surfarce. They seem to group in the direction of the like, like daphnia but unlike any other ostracod.
Very small ostracod, around 1mm maximum. Discovered in my hydra acquarium while examining the gravel with a 40x lens. Rounded, with a brownisd/reddich color and 3 big yellow spots on each valve.
Very small ostracod, around 1mm maximum. Discovered in an acquarium shop, crawling on the glass of shrimps tank. Took me quite a while to convince the shop keeper to get something out for me. In the end I got 3 and I am still waiting to see if they start to reproduce.
Very small ostracod, around 1mm maximum. Discovered in a pool in Park Josaphat dwelling on the bottom of a very shallow pond. Rounded, reddish with yellow spots.
UNKNOWN GREEN PEE OSTRACOD
Very small ostracod, around 1mm maximum, quite rounded, with some dark stripes. I do not know where he is coming from.
UNKNOWN ROMBIC SHAPE OSTRACOD
Very small ostracod, around 2/3 mm maximum, with a strange rombic shape. Found by chance in the same tank of the green one I found in the acquarium shop.