The Chaetonotida is an
order of
gastrotrichs. They generally have a tenpin or bottle-like shape.
Chaetonotids inhabit both freshwater and marine environments. They can be distinguished from other gastrotrichs by the absence of pores in the
pharynx
The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its str ...
, and by the presence of adhesive glands at the posterior end of the animal only. Most freshwater species are
parthenogenetic
Parthenogenesis (; from the Greek grc, παρθένος, translit=parthénos, lit=virgin, label=none + grc, γένεσις, translit=génesis, lit=creation, label=none) is a natural form of asexual reproduction in which growth and development ...
.
The smooth or complex cuticle has a variable number of adhesive tubes, and the pharyngeal lumen of Chaetonotids is Y-shaped. A valve may be present at the junction of the pharynx and midgut. The epidermis in most organisms in this order is partly syncytial. The Chaetonotids are divided into two suborders, Multitubulatina and Paucitubulatina. Multitubulatina are marine, hermaphroditic strap-shaped organisms. Paucitubulatina are mostly freshwater, bowling pin shaped organisms that can be hermaphroditic, parthenogenetic or both.
References
Further reading
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External links
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Gastrotricha
Protostome orders
{{Protostome-stub