Ostracods

Under the surface of the water in the small freshwater wetlands there is an unbelievable diversity of life. There are hundreds and sometimes thousands of different species of animals and plants to be found there. Among the types of animals there, you can find insects, molluscs, worms, crustaceans, beetles and even fish – like sticklebacks, and tiny floating animals called zooplankton. Some of these animals like to live in the water column, some like to crawl about on the stems of the plants growing out of the bottom of the wetland and some others like to live their lives in the muddy substrate on the floor of the wetland.

There are about 8,000 species of ostracods living on earth today. There is evidence in the fossil record that ostracods were prolific on earth almost 600 million years ago and they are still thriving today. About 20 species can be found in our freshwater wetlands. Ostracods are weirder than fiction (picture opposite) and the species found in Ireland range in size from about 0.1 mm to about 5 mm in length. As crustaceans, they rely on a bi-valve shell of hard material to protect their delicate inner organs. They can slam the shells shut to protect themselves, if threatened.