dorsal fin


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Related to dorsal fin: caudal fin

dorsal fin

[′dȯr·səl ′fin]
(vertebrate zoology)
A median longitudinal vertical fin on the dorsal aspect of a fish or other aquatic vertebrate.

dorsal fin

dorsal fin
An additional fin surface along the top of the fuselage just in front of the main fin. Dorsal fins help increase directional stability, especially at high air speeds and Mach numbers.
References in periodicals archive ?
The species name is from the Latin flavus for yellow and lineatus, in reference to a line, for the most conspicuous colour marking, the yellow line passing from behind the eye to below the first dorsal fin.
3 Meristics Dorsal fin 28 27-28 16 Caudal fin 25 24-25 24 Anal fin 21 20-21 16-18 Pelvic fin 5 5 5 Pectoral fin 12 11-12 11 Scales in longitudinal scries 25 25-26 26 Scales in transversal series 09 9-10 9 Horizontal scales around 12 12 10 Caudal peduncle
The spines along the dorsal fin and gills are for protection against predators and are not used to catch food.
Secondary sexual dimorphism: Males with reduced hooks on rays of anal, pelvic, pectoral and dorsal fins.
Dorsal rays XI, 9; anal rays III,9; dorsal and anal soft rays branched except first and second rays of dorsal fin and first ray of anal fin; the last dorsal and anal soft rays branched to base; pectoral rays 15, the upper two unbranched; pelvic rays I,5; principal caudal rays 13, the upper and lower rays unbranched; upper and lower procurrent caudal rays 3 (3-4); lateral line 16 + 6 (16 + 6-9, except one paratype with 14 + 6); scales above lateral line to origin of dorsal fin 2; scales below lateral line to anus 7 (6-7); median predorsal scales 5; median preventral scales 6 (5-6); transverse scale rows on cheek 2, the upper row with 6 (5-8) and the lower row with 10 (9-10) scales; circumpeduncular scales 15; gill rakers 15 (14-17).
These fishes are generally similar in appearance and characterised by relatively high dorsal and anal fin ray counts, and a live colour pattern that features a dark submarginal stripe and outer white margin on the second dorsal fin.
These individuals were characterized by: first dorsal fin with a single small isolated spine anteriorly; gill rakers 2-3+4-6=6-9; pored lateral line scales 73-80 and caudal fin with a yellow marking on the middle when fresh.
The Risso dolphin has a distinctive dorsal fin Niki Clear
Caption: First dorsal fin originating Behind pectoral fins
The measurable morphometric characters used were standard length (SL), Body weight (BWT), Total Body Length (TL), Dorsal Fin Length (DL) Caudal Fin Length (CL) Head Length (HL), Body width (BW).