What is a median fin?

What is a median fin?

Definition of Term. median fins (English) The fins in the median plane, hence the dorsal, anal and caudal fins. (

Where are the 4 types of fins on fish?

The unpaired fins are the dorsal, caudal, and anal; the paired fins are called pectorals and pelvics, or ventrals. Pectoral fins are present in almost every fish. They are found behind the gill cavity, and are prominent. In primitive fishes, the pectoral fins are found lower on the body, nearer the ventral side.

What are the types of fins on a fish?

For each fish, generally, there are five main fins follows: Dorsal, Pelvic, Caudal (tail), Anal and Pectoral as shown in Fig. 1. Dorsal fins are located either on the back of the fish or its top, it helps the fish during sharp turning or stops.

What are the different types of fins in a fish and its uses?

Almost all fish have fins that they use for swimming (locomotion), balance, stability, and steering. A catfish has dorsal, adipose, caudal, anal, paired pelvic, and paired pectoral fins.

What is a Heterocercal caudal fin?

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 the fin fold theory?

According to the widely accepted fin-fold theory, the paired limbs are derived from the local persistence of parts of a continuous fold that in ancestral vertebrates passed along each side of the trunk and fused behind the anus into a single fin.

How do you identify fish fins?

Identifying Fish Fins

1. Dorsal fins are found on the back of the fish.
2. Caudal fins are also known as tail fins.
3. Anal fins are on the ventral (bottom) surface of the fish, behind the anus.
4. Pectoral fins are located on each side of the fish, around where the head meets the body.

Do all fish have the same number of fins?

Most fishes have one dorsal fin, but some fishes have two or three. Caudal/Tail fins: Also called the tail fins, caudal fins are attached to the end of the caudal peduncle and used for propulsion.

What is a Diphycercal tail?

1 of a tail fin : having the upper and lower portions alike or nearly so and the vertebral column extending to the tip without any upturning in lungfish and crossopterygians this symmetry is attained by the evolution of a diphycercal tail— A. S. Romer.

What is a Homocercal tail?

Quick Reference. In fish, a tail in which the last vertebra adjoins modified bony elements (the urostyle and hypurals) which support the fin rays in such a manner that the tail fin outwardly appears symmetrical. The homocercal tail fin is typical of the higher bony fish.

What is gill arch theory?

Branchial arches, or gill arches, are a series of bony “loops” present in fish, which support the gills. As gills are the primitive condition of vertebrates, all vertebrate embryos develop pharyngeal arches, though the eventual fate of these arches varies between taxa. All basal vertebrates breathe with gills.

Where are the median fins located on a fish?

Most fish have two kinds of fins: median and paired. Median fins are single fins that run down the midline of the body. The dorsal fin is a median fin located on the dorsal side of the fish. The anal fin and caudal fin are also median fins. Paired fins are arranged in pairs, like human arms and legs.

What are the different types of fish fins?

Fins are one of the most distinguishing features of a fish and they have several different forms. Two types of fins are found in most of the fish: median and paired fins. Median fins are single in number which runs down the mid-line of the body. In fishes, median fins are dorsal, caudal and anal fins while paired fins are pectoral

What kind of structure does a fish have?

The first anatomical structures many people identify on a fish are the fins. In fact, “appendages, when present, as fins” is part of one of the scientific definitions of a fish. Most fish have two kinds of fins: median and paired. Median finsare single fins that run down the midline of the body.

How many dorsal fins does an anglerfish have?

A fish can have up to three dorsal fins. The dorsal fins serve to protect the fish against rolling, and assist it in sudden turns and stops. In anglerfish, the anterior of the dorsal fin is modified into an illicium and esca, a biological equivalent to a fishing rod and lure.