noun
cyclostomes
A taxonomic term for jawless fishes with round, sucker-like mouths, including lampreys and hagfishes. Used mainly in biology and zoology contexts.
See also: 無顎類
円口類にはヤツメウナギやヌタウナギが含まれる。
Cyclostomes include lampreys and hagfishes.
無顎類 is a broader term for jawless fishes (Agnatha), while 円口類 specifically refers to the extant cyclostomes within that group.
From 円 (round) + 口 (mouth) + 類 (group, category), referring to the round, sucker-like mouths characteristic of cyclostomes.