Keratella, similar to other rotifers, exhibits a pseudocoelomate body plan characterized by the persistence of the blastocoel into adulthood, a condition considered to be a secondary evolutionary development. These rotifers lack a foot but possess a protective outer covering called a lorica. Keratella species are found in two body forms: the tecta form, which lacks the posterior spine seen in the typica form. Typically, individuals of Keratella born in environments with predators such as cladocerans, Asplanchna, and cyclopoid copepods develop spines. Interestingly, both the typica and tecta forms can be produced by mothers of either form.