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Related to cyclostomes: agnathans, Ostracoderms


Any of various fishes lacking jaws and true teeth and having a circular sucking mouth, including the hagfishes and the lampreys.

[From New Latin Cyclostomī and Cyclostomata, class names : cyclo- + Greek stoma, stomat-, mouth.]

cy·clos′to·mate′ (sī-klŏs′tə-māt′, -mĭt) adj.


(ˈsaɪkləˌstəʊm; ˈsɪk-)
(Animals) any primitive aquatic jawless vertebrate of the class Cyclostomata, such as the lamprey and hagfish, having a round sucking mouth and pouchlike gills
(Plants) of, relating to, or belonging to the class Cyclostomata
Also called: marsipobranch
cyclostomate, cyclostomatous, cyclostomous adj

jaw′less fish`

1. Also called cyclostome. any fish of the class Agnatha (and order Cyclostomata), characterized by a circular sucking mouth that lacks jaws.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.cyclostome - primitive aquatic vertebratecyclostome - primitive aquatic vertebrate  
agnathan, jawless fish, jawless vertebrate - eel-shaped vertebrate without jaws or paired appendages including the cyclostomes and some extinct forms
Cyclostomata, order Cyclostomata - primitive jawless aquatic vertebrate: lampreys; hagfishes
References in periodicals archive ?
Timing of genome duplications relative to the origin of the vertebrates: did cyclostomes diverge before or after?
Fishes of the Western North Atlantic Part One: Lancelets, Cyclostomes, Sharks.
Comparative Ecology of Bryozoan Radiations: origin of novelties in cyclostomes and cheilostomes.
The lymphoid cells and tissues of vertebrates constitute the immune defence mechanism (Finstad et al., 1964) and its ontogenic development and architecture have attained progressive sophistication from the primitive cyclostomes to the higher vertebrates (Good et al., 1966; Manning and Turner, 1976).
Cheilostomes were distributed among all units sampled but cyclostomes were found only in the Prairie Bluff Formation.
He begins by describing the renal components and their functions, and then describes how they are developed and used by elasmobranchs, osteichthyans, cyclostomes, amphibians, reptiles, birds, and mammals.
Nevertheless, prey remains from elephant seal stomachs show that they feed on a variety of epi- and mesopelagic, bioluminescent cephalopods, teleosts such as Pacific Hake, Merluccius productus, crustaceans, elasmobranchs, cyclostomes, and tunicates.
Jackson and McKinney (1990) found that, in the Mesozoic and Cenozoic, communication among zooids was more extensive in cheilostomes than in cyclostomes and that cheilostomes largely replace cyclostomes, which implies a trend in mean degree of individuation for bryozoans as a whole.