This digitally-colorized scanning electron micrograph (SEM) depicted the dorsal (upper) surface of a Giardia protozoan that had been isolated from a rat's intestine. Some of the identifying morphologic characteristics include pairs of thread-like flagella that facilitate motility, and a ventolateral flange that appears as a ruffle around the anterior portion of the organism. Pairs of flagella seen here include an anterior, posterior-lateral, and caudal pairs. The protozoan Giardia causes the diarrheal disease called giardiasis.