anal fin

(redirected from Anal fins)
Also found in: Dictionary.

anal fin

[′ān·əl ‚fin]
(vertebrate zoology)
An unpaired fin located medially on the posterior ventral part of the fish body.
References in periodicals archive ?
Dorsal and anal fins dusky; holotype with 7 discrete black blotches of varying shape and size on interradial membranes: distally between spines 1-2, 4-5, 6-7, 8-10 and 11-soft ray 1; proximally between spines 4-6 and 7-9; subdistally between soft rays 3-5 and proximally between rays 6-8 and 9-12.
Anal fin short, not very high, with a scaly sheat, and 14 to 16 rays (mode = 16), the last two rays branched; anal fin situated at posterior one-third of the body.
Dorsal fin elongated in males, pointed, rays 7-8 much more elongated than remaining rays, filamentous, tips reaching at least distal margin of caudal fin when adpressed to the body; anal fin pointed in males, pointed, rays 78 much more elongated than remaining rays, filamentous, tips reaching distal margin of caudal fin when adpressed to body; dorsal and anal fins just slightly pointed in females.
In flexion larvae, the second, third, and fourth dorsal fin rays are elongate and almost all specimens have all the rays in dorsal and anal fins formed.
0 % of SL), all in head length; membranes between first eight dorsal spines and three anal spines deeply incised; posterior margin of soft portions of dorsal and anal fins angular, the longest dorsal and anal rays reaching as far posterior as level of middle of caudal fin, their length 1.
Frozen first anal fins were thawed, and the second spiny ray was selected (Berkeley and Houde, 1983), removed, and cleaned of all tissue.
The specimen has the following meristic characteristics: dorsal fin rays--81; anal fin rays--67; pectoral rays--11; pelvic fin rays--6; lateral line pores, eyed side--65; and lateral line pores, blind side-0.
5); cleithrum, first pterygiophore of dorsal and anal fins, and neural spines of vertebrae relatively slender and never hyperossified; in specimens >20 cm FL, heights of longest dorsal- and anal-fin rays both 0.
It is distinguished from congeners, and especially from M misoolensis, by a combination of features that include a distinctive colour pattern with yellow dorsal, anal, and pelvic fins, usually 18-19 rakers on the first gill arch, 11-16 cheek scales, 12-13 circum-peduncular scales, first dorsal fin situated well behind anal fin origin, presence of both vomerine and palatine teeth, conspicuously rounded anal fin with relatively elongate rays on the anterior half, and relatively slender body in both sexes (greatest depth usually less than 35% SL).