FISH FINS A fin is a thin component or appendage attached to a larger body or structure. most distinctive features of a fish Compose of bony spine protruding from the body with skin covering them and joining them together, either in a webbed fashion, as seen in most bony fish , or more similar to a flipper, as seen in sharks.  Fins are appendages used by the fish to maintain its position, move, steer and stop. Fins give fish mobility, stability, and maneuverability. •Help in protection form predator

Flipper Webbed

Help in identification position of dorsal fin shape of dorsal fin

GROUPS OF FINSFins are composed of two groups Paired and

unpaired Paired Fins Pectorals Pelvics or VentralsUnpaired fins Dorsal Caudal or tail Anal

FUNCTION OF PAIRED FINS

Paired fins can be used as the main means of propulsion or in combination with other swimming or crawling forms.

 The pectoral and pelvic fins are also commonly used as a means of

Quickly stopping the fish, Controlling pitching (change of position from the

horizontal) and to Attract mates or startle other fish. Two well known examples of the use of the pectoral

fins for primary propulsion are: Labrids - the rowing type movement of the wrasse. Rajiform - the bird like swimming of the skates and

rays

PAIRED

1:PECTORAL FINS On side of body , behind gill cavity In primitive fishes, the pectoral fins are

found lower on the body, nearer the ventral side.

In some look like an arm-like extension. In other cases, the pectoral fins haveevolved

to look like wings for South American flying fish

a pad for resting on the bottom in some catfish.

2:PELVIC FINShe pelvic fins are generally smaller than the The pelvic fins are located ventrally below and

behind the pectorals. Pelvic fins function in stabilizing , braking,

move up and down They are of little use for locomotion. Some have spines and rays on them. Other fish have modified pelvic fins in the form

of a sucker for holding on rocks.eg Gobies Some fish have even lost their pelvic fins

completely, especially those that spend their lives scouring along the ocean floor.

UNPAIRED1:DORSAL FINS Dorsal fins are located on the back or on the

top of the fish Aid the fish in sharp turns or stops, and

assist the fish in rolling.  Fish may have up to three distinct dorsal

fins, known as proximal, middle , and distal  dorsal fins

DORSAL FINS

several fish have just two dorsal fins with the middle and distal fins fused together.

May be a fleshy ray, or quite large and supported by spines.

Dorsal fins have been modified in the remoras into a sucking disc that allows them to cling to sharks or other large fishes.

In the anglerfish, the dorsal fin has been modified into a fishing rod and lure.

Angler fish

Dorsal fin

TYPE OF DORAL FINS

The type of Doral fins are: Single Split Pointed Trigger Spine Triangular Trailing

2:TAIL FIN OR CAUDAL FIN

The caudal fin is the tail tail located at the end of the caudal peduncle.

For fish identification, the type of Caudal fin is used to distinguish one type from another.

Types of caudal fin Indented Round Square Forked Lunate Pointed Emarginate Heteroceral

3:ANAL FINS The anal fin is located on the ventral

 surface behind the anus The anal fin is usually short, but some

fish have anals that stretch from near the chin, to the caudal fin.

Very few fish have more than one anal fin(i.e., the cods),

•some do not have one at all (i.e., skatesand rays).• In some species,the anal fin has modified into an organ used in copulation called gonopodium.

4:ADIPOSE FIN

Fishes such as catfish have another fleshy lobe behind the dorsal fin, called an adipose (fat) fin

Its function has remained a mystery 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

FINLETS OR SCUTES

Finlets are small fins located between the dorsal fin and the tail of the fish

anal fins and the tail of the fish. These finlets are found on fast

swimming fish like tuna, and is said to aid in the speed of the fish, by cutting through the water.