Similar to another ancient lake, Tanganyika, Baikal is a center for ostracod diversity. About 90% of the Lake Baikal ostracods are endemic, meaning that there are 200 endemic species. This makes it the second-most diverse group of crustacean in the lake, after the amphipods. The vast majority of the Baikal ostracods belong in the families Candonidae (more than 100 described species) and Cytherideidae (about 50 described species), but genetic studies indicate that the true diversity in at least the latter family has been heavily underestimated. The morphology of the Baikal ostracods is highly diverse.