An unpaired fin located on the underside of a fish posterior to the anus.
〔动〕臀鳍
Example sentencesExamples
The second dorsal and the anal fin are well-separated from the caudal fin.
The dorsal and anal fins, which push the fish along, are way off the central axis of its body, yet the animal swims a straight path without rocking up and down.
The siganids have many strong spines with venom glands in dorsal and anal fins that contain a painful toxin.
The fleshy, stalk-like pectoral and pelvic fins and similar fleshy second dorsal and anal fins are also unlike any other marine fishes.
Dorsal and anal fins are typically completely formed by the time the fish has reached 7-13 mm.
Definition of anal fin in US English:
anal fin
noun
Zoology
An unpaired fin located on the underside of a fish posterior to the anus.
〔动〕臀鳍
Example sentencesExamples
The dorsal and anal fins, which push the fish along, are way off the central axis of its body, yet the animal swims a straight path without rocking up and down.
The siganids have many strong spines with venom glands in dorsal and anal fins that contain a painful toxin.
Dorsal and anal fins are typically completely formed by the time the fish has reached 7-13 mm.
The second dorsal and the anal fin are well-separated from the caudal fin.
The fleshy, stalk-like pectoral and pelvic fins and similar fleshy second dorsal and anal fins are also unlike any other marine fishes.