What does cyclostomatous mean?
Cyclostomatous is a specialized zoological adjective describing animals that possess a round or circular mouth, most notably members of the group Cyclostomata. In its best-known application it refers to the jawless fishes—lampreys and hagfishes—whose mouths form rounded, suctorial discs rather than hinged jaws equipped with teeth. The word also has a second, entirely distinct zoological use: it describes certain colonial bryozoans, sometimes called moss animals, whose individual zooecia terminate in small circular apertures. Derived from the Greek roots kyklos (circle) and stoma (mouth), the term is essentially confined to scientific writing on comparative anatomy, evolution, and paleontology. It carries no figurative or colloquial use and no emotional connotation; its value lies in precision. For readers of natural history, encountering cyclostomatous signals a discussion of some of the most primitive body plans in the animal kingdom, from parasitic lampreys to ancient marine colonies preserved as fossils.
adjectiveHaving a circular or round mouth; specifically, belonging or relating to the Cyclostomata, a group of jawless fishes (such as lampreys and hagfishes) characterized by a round, suctorial mouth, or to an order of colonial bryozoans with round-mouthed zooids.
- Of or relating to the Cyclostomata: jawless aquatic vertebrates such as lampreys and hagfishes, having a round, suctorial mouth.
- Of or relating to the Cyclostomata in a second zoological sense: an order of colonial bryozoans whose zooids open through circular apertures.
- More generally, having a round or circular mouth.
"The lamprey's cyclostomatous anatomy allows it to attach to its host with a ring of rasping teeth."
"Hagfishes and lampreys are cyclostomatous vertebrates, lacking both jaws and paired fins."
"Under the microscope, the cyclostomatous bryozoan colony revealed rows of tubular zooids with perfectly round apertures."
From lampreys that latch onto fish with their ring-like mouths to moss-animal colonies with tiny circular openings, 'cyclostomatous' names one of nature's strangest body plans.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cyclostomatous
Cyclostomatous derives from the combination of two Greek roots: kyklos, meaning circle or wheel, and stoma, meaning mouth, joined by the adjectival suffix -ous via New Latin scientific usage. The compound was coined in the nineteenth century as biologists formalized the classification of Cyclostomata, first applied to jawless fishes such as lampreys and later adopted for the bryozoan order of the same name. Related forms include the noun cyclostome, denoting an individual animal with such a mouth.
Related word forms
How cyclostomatous is actually used
Strictly technical vocabulary used in zoology and paleontology; rare in general prose. Because 'Cyclostomata' names two quite different animal groups (jawless fishes in ichthyology, bryozoans in malacology/paleontology), the term is best used with context making clear which group is meant.
Easily confused with cyclostomatous
Cyclostationary describes signals whose statistical properties vary periodically, whereas cyclostomatous describes organisms with a round mouth.