ventral fin


Also found in: Dictionary, Thesaurus, Medical, Wikipedia.

ventral fin

ventral fin
A vertical, stabilizing fin on the lower rear portion of a fuselage that helps increase directional stability, especially at higher Mach numbers, by increasing the area behind the vertical axis.
References in periodicals archive ?
The meristic features of the two most abundant fish species caught were as follows: Citherinus citharius had: Dorsal fins, 20, Anal fins, 30, caudal fins 21, pectoral fins 9 and 8 ventral fins. Alestes nurse had 10 dorsal fins, 14 anal fins, 31 caudal fins, 7 pectoral fins and 6 ventral fins Table 3 (D9).
Pectoral fin origin to ventral fin 32.5###29.3 31.1###1.0###36.3 28.7###31.1###1.4###33.4###28.7 30.3###0.9###32.4 28.7###30.5###0.9
The ventral fins are short and approximately at the same level as the third dorsal-fin ray.
The pilot tried to keep the air craft flying but the ventral fins contacted the runway making further rotation impossible.
chrysospilos has ventral fins displaced forwards, underneath the pectoral fins, and joined at their base in a type of sucker that lets them climb up the roots and trunks of the trees of the mangrove swamp.
7); scales immediately behind pectoral origin cycloid, but becoming more strongly ctenoid posteriorly; scales on caudal peduncle strongly ctenoid; scales on chest laterally and ventrally strongly ctenoid; large interpelvic scale present; scales on belly weakly ctenoid, about 1/3 smaller than flank scales and imbricating; scales on anal-genital region of similar size to flank scales, weakly to strongly ctenoid; scales on caudal cycloid, arranged in single row between and along rays; two scale rows between upper and lower lateral line, rostrally and caudally; four scale rows between upper lateral line and base of dorsal; four scale rows between bases of pectoral and ventral fins. Lateral line scales 20+10 (holotype), highly variable in paratypes, especially in small specimens, e.g.