The Chaetonotida is an order

Order (biology)

In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...

 of gastrotrich

Gastrotrich

The gastrotrichs are a phylum of microscopic animals abundant in fresh water and marine environments. Most fresh water species are part of the periphyton and benthos...

s. 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

Pharynx

The human pharynx is the part of the throat situated immediately posterior to the mouth and nasal cavity, and anterior to the esophagus and larynx. The human pharynx is conventionally divided into three sections: the nasopharynx , the oropharynx , and the laryngopharynx...

, and by the presence of adhesive glands at the posterior end of the animal only. Most freshwater species are parthenogenetic

Parthenogenesis

Parthenogenesis is a form of asexual reproduction found in females, where growth and development of embryos occur without fertilization by a male...

.