anal fin

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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 ?
The presence of more than three anal fin spines is also characteristic of the Cichlidae and excludes identification as a labroid (Carpenter, 2001).
11b In adults, body with 8-9 dark incomplete vertical stripes; scaly basal sheath along the lobes of the dorsal and anal fins with relatively wide scales above which the fins are devoid of small scales; back of the eye covered by a weak adipose eyelid that does not reach the posterior edge of the pupil: Caranx vinctus
The main part of the body is covered with cycloid scales, but unlike females, males have also ctenoid scales on the head on the eye-side and on the trunk behind the head and close to dorsal and anal fins.
Fins almost entirely scaled except for membranes of spinous dorsal and anal fins and posterior portions of the unbranched pectoral rays.
Dark lateral stripe continuous with caudal-peduncle spot; caudal-peduncle spot rounded, and not extending onto middle caudal-fin rays; 15-17 pored lateral-line scales; six scales between lateral line and anal-fin origin; six scales between lateral line and pelvic-fin insertions; nine predorsal scales; ii,8,i dorsal-fin rays; anal fin with 21-22 branched; pectoral-fins with twelve branched rays; males with bony hooks on anal and pelvic fins H.
rei-t-hertz), lower anal fin base length and caudal fin length in males, and the lower head depth (except in A.
Color (from fresh specimens)Head and dorsal part of body dull olive silvery, becoming silvery-white up to belly; scales with dark margins forming faint lines dorsally on body; dorsal-fin and anal rays grey, soft rays hyaline, membranes of the dorsal and anal fins aredusky grey; pectoral fins light yellow to whitish anddistinctly stouter and longer than third spine, the
Male anal fins were approximately 3 mm longer than female fins and male dorsal fins were 2 mm longer.
In courtship looping, the male, with lowered dorsal and anal fins, swims rapidly around the female one or more times in a tight, horizontal circle with a radius (possi ly constrained y size of the aquarium) two or three times the length of the female.
Both the dorsal and anal fins were small and little elevated above the profile of the already tapering caudal peduncle (Figs 2D, 7B, C).