The large unpaired fin on the middle of the back.Some fishes have more than one.The fin supports may consist of soft-rays, spines, or both.

fin on the back of fishes and some other aquatic vertebrates.

The fin on the back of a whale or dolphin. In many species, individual animals can be identified by the shape, nicks and scars on their dorsal fin.

a small single fin

the tall, spire-like fin on the back of the orca, which can reach 1.7 metres in height for males. Nicks in the dorsal fin are useful in identifying individuals.

appendage on the mid back of all fish.

The fin that is located on the center back of a whale.

an unpaired fin on the back; there may be up to 3 dorsal fins

The fin running across the back of the fish. Search for more information...

the fin on a whale's back. Fins consist of dense, fibrous connective tissue, with no bones.

The main fin on the dorsal surface of certain marine mammals and fishes.

the large fin located along the midline of the back of most fishes and cetaceans. In some fishes it is divided into separate fins.

The dorsal fin is the uppermost fin, located between the body and the tail.

the single fin along the back of a fish, between the head and caudal fin. Some other kinds of fishes have two dorsal fins, some have a dorsal fin and an adipose fin. Poeciliids only have a single dorsal fin.

Back fin, with rays or spines.

median fin on back, with rays and sometimes spines

The fin or finlike parts on the back of the salmon

The fin at the top of the body of the fish. Some fish have two, one behind the other.

The fin directly on the top of the body (it's the fin that sticks out of the water when you see a shark). Some fish have two dorsal fins one directly behind the other.

The fin at the top of many fish. In many species of fish (such as cichlids) is distinctly separated into a spiny front portion followed by a "soft" rear portion.

A midline, unpaired, vertical fin sited on the back of aquatic vertebrates.

the fin on the back, usually central in position

a fin located on the backs of fish es, whale s, dolphin s and porpoise s

an unpaired medial fin on the dorsal aspect of a fish that provides lateral stability while swimming

the tall triangular fin on the shark's back When there are two dorsal fins the front, one is bigger than the back one.

Fin on the back of a fish: may be divided into parts on some species.

A fin on the back of a fish. It helps a fish keep its balance as it moves through the water.

the fin located on the center part of the backs of fish and some marine mammals, such as killer whales and dolphins

the prominent fin on the back, can be 1 or more fins. Front dorsal has spiny rays, second and third(if any) softer rays.

the fin along the midline of the back of most whales and dolphins.

Single fin mounted on top of the fish. located between the head and the tail. Some species have two, one behind the other.

A median fin along the back which is supported by rays. There may be two or more dorsal fins, in which case the most anterior one is designated the first. ( 126) See chart for details.

The structure on the back of most cetaceans (not supported by bone).  Some species only have a dorsal hump or ridge, others have no dorsal structure at all. Different forms: dorsal ridge, falcate fin, rounded fin, triangular fin.

prominent, unpaired fin or fins located on the mid-line of the back of the fish.

the fin on the back of the fish.

See fins of a fish.

the fin on the back of a fish, sometimes divided into two or three partly or entirely separate sections. Drainage A drainage basin or a drainage system; the process of draining.

The fin along the midline of the back (the top fin in marine vertebrates). See examples. A COOKIE CUTTER SHARK, Isistius brasiliensis, approx. 20" (50 CM) jump to

the only major fin located on the back of most fish.

The large single fin located along a salmon's back.

Large fin or fins on a fish’s back that vary in shape and size and may be connected or separate.

Single fin on the dorsal surface.

solid dorsal structure, often falcate shaped, made up of connective tissue; the dorsal fin is not connected to the skeleton; particularly developed in fast swimming species, it is thought to work as a body stabilizer

median rayed fin on the back.

The dorsal fin is the uppermost vertically placed fin, located on the back surface of a fish. Although usually singular, some fish species possess two.

The single fin on top of the back

A single fin found on the whale's back. Some dorsal fins may have scarring or other marks on it which help biologists to identify certain individuals..

The fin located on top of a fish. Most fish species have only one dorsal fin, but some will have two, one behind the other. Many species of clownfish will have two dorsal fins.

The fin/fins of the midline of the back of the fish or marine mammal. Dorsoventrally compressed - Elongated and/or flattened; length much greater than height.

This fin is located at the top of the fish. Evaporation: Is the process in which a liquid is altered to a vapor state.

The dorsal fin runs down the back of the fish and assists in maintaining its balance.

The median fin on the back of fishes. It may be divided into spiny-rayed and soft-rayed parts.

Raised structure on the back of most cetaceans.

This is the fin that is located along the fishes back.

In the fishes, the often prominent, ray supported fin along the midline of the back, occasionally divided into two fins. An important indicator in distinguishing among some families and species of our native fishes.

The dorsal fin is a fin on an animal's back. Many cetaceans have dorsal fins.

A dorsal fin is a fin located on the backs of fishes, whales, dolphins, and porpoises, as well as the (extinct) ichthyosaurs. Its main purpose is to stabilise the animal against rolling and assist in sudden turns. Some animals have developed dorsal fins with protective functions, such as spines or venom.