This desease is created by a unicellular organism, so called 'mixozoa', with the name 'Thelohania contejani'. Crustaceas are suffering about this something more than fish do. The mixozoa are destroying the muscles. The appearing white spots can be realized through the link-skin at the claws and the legs for example. The desease is spread when other crabs are feeding the dead and sick crabs! A medical treatment is impossible because no medicine is availible. Furthermore some other unicellular organisms are able to affect the inner organs of the crabs.But if the crabs are getting sick because of these critters noone knows.Possibly some are nessessary.
LEECHES IN CRUSTACEAS
Thes parasites are looking like 5 - 10mm darkyellow worms. They are sticking at the links of the crabs,the eyestalks and the bottom. easy to realize, these wormsare not dangerous to the crabs. With the next molt the crabs can get rid of them.Maybe in tanks, where the parasites may appear in great amounts, they'll maybe harm the crabs.