Is caudal fin Heterocercal or Homocercal?

Is caudal fin Heterocercal or Homocercal?

Homocercal tails are the most common caudal fin type in fish but can come in many symmetrical shapes. A homocercal tail is contrasted with a heterocercal tail which has unequal lobes.

What is a Heterocercal caudal tail?

A heterocercal tail is a caudal fin composed of two asymmetrical lobes. Often, such as the case in many sharks, the vertebral column passes through the upper lobe, making it the larger of the two lobes. A heterocercal tail is contrasted with a homocercal tail which has equal lobes.

What is a Heterocercal caudal fin used for?

The caudal fin of leopard sharks functions in a manner consistent with the classical model of heterocercal tail function in which the caudal surface moves at an acute angle to the horizontal plane, and hence is expected to generate lift forces and torques which must be counteracted anteriorly by the body and pectoral …

What is the Heterocercal tail in sharks?

The heterocercal tail is capable of delivering a thrust that can be oriented in a wide range of angles in the vertical plane. The orientation results from a balance of forces acting in the tail.

What is Heterocercal and Homocercal?

A homocercal tail is a caudal fin composed of two lobes of equal proportion. A homocercal tail is contrasted with a heterocercal tail which has unequal lobes.

Who has Heterocercal tail?

sharks
The heterocercal tail is present in many fossil fish, in the sharks (Chondrichthyes), and in the more primitive bony fish, e.g. the families Acipenseridae and Polyodontidae.

Do bony fish have Heterocercal caudal fins?

Caudal fin It also regulates the speed of forward movement. The caudal fin of bony fish is called a homocercal tail because both the upper and lower lobes are the same size (or symmetrical), unlike in sharks where the upper lobe is generally larger than the lower lobe (referred to as a heterocercal tail).

What is the purpose of a Heterocercal caudal tail in sharks?

An alternative model suggests that the heterocercal shark tail functions to direct reaction forces through the center of mass.

What is the difference between Homocercal and Heterocercal?

A homocercal tail is a caudal fin composed of two lobes of equal proportion. Homocercal tails are the most common caudal fin type in fish but can come in many symmetrical shapes. A homocercal tail is contrasted with a heterocercal tail which has unequal lobes.

What is a caudal fin on a shark?

Shark tail fins, also called the caudal fins, are unique among all fishes. If you look at the top half of the fin, it is noticeably longer than the bottom half. This asymmetrical profile was common in many ancient fishes, but sharks are the only group to maintain the shape over a period of 350 million years.

What is Homocercal fin?

1 of a fish tail fin : having the upper and lower lobes approximately symmetrical and the vertebral column ending at or near the middle of the base. 2 : having or relating to a homocercal tail fin.

How did the basal actinopterygians transition from the ancestral heterocercal to derived caudal fin?

The transition from the ancestral heterocercal form to the derived homocercal caudal fin remains poorly understood. Few developmental studies provide an understanding of derived and ancestral characters among basal actinopterygians.

Is the tail of a shark heterocercal?

The tail of a shark is a heterocercal fin. This means that one lobe is larger than the other and is an extension of the vertebral column. In the case of sharks, the top lobe is the larger one.

What is the shape of the caudal fin on a shark?

Caudal fin shapes vary considerably between shark species, due to their evolution in separate environments. Sharks possess a heterocercal caudal fin in which the dorsal portion is usually noticeably larger than the ventral portion.

What does the blue dot on the caudal fin mean?

Sequence of development and ossification of individual caudal fin skeletal elements based on average values. Diamonds indicate earliest appearance of elements by cell condensation. Blue indicates Alcian Blue uptake and development of cartilage. The blue-to-red transition represents the progression of ossification.