The Apostomatida are an order of
ciliates from the class
Oligohymenophorea. Individual organisms from this the order are called apostomes. They are
symbiotic
Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...
with
Crustacea
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean gro ...
. For majority of their life cycle they are
dormant
Dormant, "sleeping", may refer to:
Science
*Dormancy
Dormancy is a period in an organism's life cycle when growth, development, and (in animals) physical activity are temporarily stopped. This minimizes metabolic activity and therefore helps ...
and
encysted on their host's
exoskeleton. The life cycle of apostomes varies; most genera will multiply through the biological process of fission causing the
larvae to develop within the crustacean host. Physical characteristics may include a small
cytostome (mouth), often accompanied by a glandular rosette and sparse hair like projections (
cilia
The cilium, plural cilia (), is a membrane-bound organelle found on most types of eukaryotic cell, and certain microorganisms known as ciliates. Cilia are absent in bacteria and archaea. The cilium has the shape of a slender threadlike projecti ...
) arranged in spiral rows on the organism.
References
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Ciliate orders
{{ciliate-stub