calotheca calotheca calotheca is the name used for a genus of choanoflagellates in the family acanthoecidae, though this name is a junior homonym of the name calotheca heyden, 1887, and it must be replaced under the rules of the iczn. the species c. alata is from indo-pacific localities. calotheca scientific classification class: choanoflagellatea order: acanthoecida family: acanthoecidae genus: calothecah. a. thomsen and o. moestrup, 1983 species calotheca pallida (bryant, 1945) calotheca parvula (weise, 1908)