Rail fins evolved into being and surged into popularity as riders ( Simon Anderson, most famously ) sought a solution to two major performance issues of a central " single " fin-both related to engagement of the foil: For one, a centrally-mounted fin is tilted up out of the water as the board is leaned over, and thus it loses more and more of its lift as the lean angle increases-if the lean angle is acute enough, the fin's tip can be the only area left in the water ; the tip may then rapidly stall and, having lost its lift, become disengaged from the water, leaving the board's bottom as the only control surface still operating.

This word may derive from the culinary practice of sticking the fish's tail and fin to the slices in identifying the fish being eaten.

The sea lions may respond to the dorsal fin of a killer whale and remain vigilant, even when encountering resident fish-eating pods.

*** The tail fin may be rounded at the end.

*** The tail fin may be truncated, or end in a more-or-less vertical edge ( such as in salmon ).

*** The fin may be forked, or end in two prongs.

*** The tail fin may be emarginate, or with a slight inward curve.

*** The tail fin may be lunate, or shaped like a crescent moon.

Additional released in 2011 has suggested that the fin may be vital for the detection of and response to stimuli such as touch, sound and changes in pressure.

A fin of a heat sink may be considered to be a flat plate with heat flowing in one end and being dissipated into the surrounding fluid as it travels to the other.

Stocky body, bulbous forehead, no prominent beak, long flippers sharply pointed at the tip, black or dark grey color, fin set forward on body, fluke raised before deep dive, may float motionless at the surface, frequently seen in very large groups, prefers deep water, may be approached.

The fillings may contain a variety such as savory roasted chicken, pork, shark fin or sweet mung beans, coconut or durian.

The extensive dorsal and anal fins may merge or nearly merge with the tail fin.

In some species, such as the royal threadfin ( Pentanemus quinquarius ), the thread-like rays may extend well past the tail fin.

They have a single, somewhat high dorsal fin running nearly the entire length of the back ; it may contain 54-58 pliable spines.

Experienced scuba divers may often be identified by the fact that they maintain neutrality without any fin use, as fish do.

The dorsal fin is very small and hooked ; its size is considerably smaller than that of the dwarf sperm whale and may be used for diagnostic purposes.

Identification may be close to impossible at sea – however, the Dwarf is slightly smaller and has a larger dorsal fin.

The first dorsal fin is small, high and pointed ( and may be spinous ); the second dorsal fin runs along the rest of the back and merges with the tail and extensive anal fin.

The dorsal fin has 10-14 rays ; in front of it are the three spines that give the fish its name ( though some individuals may have only 2, or 4 ).

All fins are large, showy and elongated ; the first high dorsal fin usually has four spines ; in males, the first of these spines may be further adorned with filamentous extensions.

The dorsal and anal fin also contain basal cartilages, not just fin rays.

The flukes ( lobes of the tail ) and dorsal fin are formed of dense connective tissue and do not contain bone or muscle.

The pectoral fins contain 15-18 soft rays each ; the pelvic fins are thoracic and contain one spine and six soft rays ; the caudal fin is forked.

The single dorsal fin originates behind the pectoral and pelvic fins and contains 1 – 3 weak spines and 9 – 18 soft rays ; the pectoral fins are elongate and tapered ( the superior rays being longer than the inferior rays ) and contain 12 – 16 soft rays.

Two-spined blackfish are similar in shape and appearance to river blackfish, though their spiny dorsal fin usually contain only two spines ( hence their scientific name ) in comparison to river blackfish which have 7 to 13 distinguishable spines in their spiny dorsal fin.

The dorsal fin is small, visible only briefly during the dive sequence.

alt = Killer whale with only top of back and dorsal fin visible above water surface, the dorsal fin curves backward at the tip.

* originated by crossbreeding numerous different established varieties with " scaleless " German carp ( generally, fish with only a single line of scales along each side of the dorsal fin ).

The study of English and European artifacts in general has revealed that projectiles were made with a widely variable number of microliths: in Tværmose there was only one, in Loshult there were two ( one for the tip and the other as a fin ), in White Hassocks, in West Yorkshire, more than 40 have been found together ; the average is between 6 and 18 pieces for each projectile.

Again, in most members, the gill plates are covered over with skin, the only gill opening a small slit above the pectoral fin.

All designs were evolved from the early Taylorcraft with a sprung skid or tailwheel beneath the fin ( except for a low-wing aircraft called the " Agricola " designed for crop-spraying ; only two of these were completed ).

Even though the term " courtly love " does appear only in just one extant Provençal poem ( as cortez amors in a late 12th century lyric by Peire d ' Alvernhe ), it is closely related to the term fin ' amor (" fine love ") which does appear frequently in Provençal and French, as well as German translated as hohe Minne.

However, they differ from most of their relatives in having only a dorsal fin on their back ; most other Ostariophysi have a small fleshy adipose fin behind the dorsal fin.

The sickle shaped caudal fin is used only to escape predators.

* 1984 – " The NeverEnding Story ( L ' histoire sans fin )" ( FRA No. 7 < small >< nowiki > version – France only </ small >

* The spiny and soft ray portions of the dorsal fin are continuous, so there is only one long fin instead of two short separate ones as for the wreckfish Polyprion americanus, scup Stenotomus chrysops, rose fish Sebastes marinus, cunner Tautogolabrus adspersus, striped bass Morone saxatilis.

The dorsal fin is normally folded close to the body, and it is only spread out as an aggressive posture reaction to other sea bass.

Giant squid can grow to a tremendous size ( see Deep-sea gigantism ): recent estimates put the maximum size at for females and for males from caudal fin to the tip of the two long tentacles ( second only to the colossal squid at an estimated, one of the largest living organisms ).

2003 brought about the influential and legendary 4-trac, along with a wakeskate-specific fin that allowed for not only nose slides, but bluntslides and manual variations.

Prior to 2006, there had only been two confirmed sightings of Bryde's whale in the eastern North Pacific north of Baja California -- one in January 1963, only a kilometer off La Jolla ( originally misidentified as a fin whale ), and another in October 1991 west of Monterey Bay.

The denticle herring ( Denticeps clupeoides ) is a small ( 15 cm ) species of ray-finned fish found only in the rivers of Benin, Nigeria and Cameroon, related to the herrings, but notable for its large anal fin and its array of denticle like scales under the head giving it almost a furry appearance.

Hexanchiform sharks have only one dorsal fin, either six or seven gill slits, and no nictitating membrane in the eyes.

The species has only a small, triangular lump in the place of a dorsal fin.