What is the most diverse fish?
Bony fishes
‘ Bony fishes are the most diverse of all groups of fishes and are also the most diverse group of vertebrates alive today, with approximately 29,000 living species. Bony fishes include two subgroups—the ray-finned fishes and the lobe-finned fishes.
Are fish genetically diverse?
It has been shown that, on average, marine fish have about 6% of the genetic variation distributed among populations, while anadromous species have 11% and freshwater 22% (Ward et al., 1994).
What do you mean by fish diversity?
Abstract. Fish have great diversity and hence they can be classified in different categories. “Fish” generally refer to several aquatic animals but actually all of them are not fish, such as starfish, shellfish, cuttlefish, jellyfish and crayfish. Bony fish are categorized into the lobe finned and ray finned fish.
What are the three classifications of fishes?
Fishes are typically divided into three groups: superclass Agnatha (jawless fishes), class Chondrichthyes (cartilaginous fishes), and superclass Osteichthyes (bony fishes).
Why are fish so diverse?
One reason fish are so diverse is that 70 percent of the planet is covered in water. The animals in this group live in a variety of habitats ranging from coral reefs and kelp forests to rivers, streams, and the open ocean. Another is that fish are very old on the evolutionary scale.
What are examples of genetic diversity?
For example, the population of humans consists of individuals with different physical traits reflecting their genetic diversity. Apart from between species, genetic diversity may also be observed among species. For instance, the population of dogs may consist of different breeds of dogs.
Why fish diversity is important?
As well as having intrinsic value, biodiversity has aesthetic value: many of us have admired the wonderful colours and shapes of fishes on coral reefs and in other coastal habitats. Moreover, biodiversity is important for the future sustainabil- ity of marine natural resources that include commercial fisheries.
What are the 5 groups of fish?
There are about 28,000 existing species of fish, and they are placed in five classes: hagfish, lampreys, cartilaginous fish, ray-finned bony fish, and lobe-finned bony fish.
What are the two classes of fish in which class is the shark?
The sharks, rays, and chimaeras make up the second group of fish, the Class Chondrichthyes. Sharks are one of the earliest known jawed fishes.
Why is ocean life so diverse?
Scientists estimate that 25 percent of all marine species live on coral reefs, making them one of the most diverse habitats in the world. Ocean life is not evenly distributed. Life in the euphotic zone is very diverse due to availability of sunlight and diversity of producers found in this zone.
What characteristics make a shark a shark?
What Makes a Shark a Shark?
- Cartilaginous skeleton. Unlike fishes with bony skeletons, a shark’s skeleton is made out of cartilage.
- Pectoral fins. While skates and rays also have cartilaginous skeletons, sharks have very different body shapes.
- Gill slits.
- Oily liver.
What is the evolution of fish?
The evolution of fish began about 530 million years ago during the Cambrian explosion. It was during this time that the early chordates developed the skull and the vertebral column, leading to the first craniates and vertebrates. The first fish lineages belong to the Agnatha, or jawless fish.
Why is the Devonian known as the age of fishes?
This has led to the Devonian being known as the age of fishes. It was from the lobe-finned fish that the tetrapods evolved, the four-limbed vertebrates, represented today by amphibians, reptiles, mammals, and birds. Transitional tetrapods first appeared during the early Devonian, and by the late Devonian the first tetrapods appeared.
How did fish diversity change during the Carboniferous and Permian periods?
During the Carboniferous period, fish diversity seemingly declined and reached low levels during the Permian period.
What are the ancestors of fish?
The first ancestors of fish, or animals that were probably closely related to fish, were Pikaia, Haikouichthys and Myllokunmingia. These three genera all appeared around 530 Ma.