What is "psorosperm"

Psorosperm \Pso"ro*sperm\, n. [Gr. ? itching + ? seed.] (Zo["o]l.) A minute parasite, usually the young of Gregarin[ae], in the pseudonavicula stage.

n. (context zoology English) A minute parasite, usually the young of Gregarinae, in the pseudonavicula stage.

Psorosperm (from the Greek ψωρα itch and σπερμα seed) is a name formerly given to a number of parasitic protozoa which produce cystlike or sporelike structures in the tissue of hosts, but now essentially obsolete.

• Some which affect vertebrate hosts are now identified as coccidia.
• Others, such as the cause of pébrine in silkworms, are now recognized as microsporidians, and some are regarded as myxosporidians.
• The genus Psorospermium (which includes the species Psorospermium haeckeli) itself is a parasite of crayfishes, and belongs to an enigmatic group of unicellular organisms which some biologists think may be related to the common ancestors of animals and fungi.

The term was introduced in German (as Psorospermien) by J. Müller in 1841.

Psorosperm was at one point believed to be the cause of Darier's disease.

"Psorospermiasis" is classified under 136.4 in ICD-9.