Mussel shrimp (ostracoda) are small, hard-shelled crustaceans. They have two hinged shell halves that make them look like small mussels (hence the name). Mussel shrimp reproduce mostly via parthenogenesis (virgin generation). They are often used as index fossils in paleontology. Today there are around 10,000-15,000 species of mussel crabs living in a wide variety of habitats, such as in ponds, streams, the deep sea and even on (wet) land.
The species, which is normally found in aquariums, grows to about 3-5mm in length, is oval and translucent, and moves by crawling and hopping.
Since it only eats algae, dead plant parts and protozoa, it is harmless to fish and shrimp.
value as fish feed
Many fish like to eat them, but they cannot chew the crabs, so they are passed out undigested and the nutritional value is zero.
Irrespective of this, mussel crabs are quite interesting observation objects that are worth a closer look.
mussel crabs:
Clam shrimp size comparison with 5 day old Crystal Red shrimp:
Mussel crabs under the microscope: