The first fish lineages belong to the Agnatha, or jawless fish. Early examples include Haikouichthys. During the late Cambrian, eel-like jawless fish called the conodonts, and small mostly armoured fish known as ostracoderms, first appeared.
What is the major difference between fish A and fish B in?
Which structure pictured in Figure 28-2 is analogous to your lungs. What is the major difference between fish A and fish B in the figure. (Fish A is a catfish, a bony fish. Fish B is an eel, a lawless fish.)
What group of fish is most closely related to tetrapods?
Support for Lungfish as the Closest Relative of Tetrapods by Using Slowly Evolving Ray-Finned Fish as the Outgroup | Genome Biology and Evolution | Oxford Academic.
Which group of fish is most closely related to land vertebrates?
Since its discovery, many comparative morphologists and paleontologists considered the coelacanth to be the closest living relative of the land vertebrates (1-4), although the lungfish were historically thought, and continued to be thought by some researchers, to hold that claim.
What is the most primitive fish?
This group is the most primitive of the three groups of fish. The fish belonging to this group have no jaws. Their mouths are like holes in their heads that lack movable parts. This group is the earliest to appear in the fossil record.
Why do fishes have 2 colorations?
Answer. The colouration of a fish is produced by three colour pigments which are largely contained within cells called Chromatophores. The 3 pigments are Erythrin (Red), Melanin (Black), and Xanthin (Yellow) each of which occurs in different chromatophores.
What is the classification of a fish?
Fishes are typically divided into three groups: superclass Agnatha (jawless fishes), class Chondrichthyes (cartilaginous fishes), and superclass Osteichthyes (bony fishes). The latter two groups are included within the infraphylum Gnathostomata, a category containing all jawed vertebrates.
Which lobe finned fish is alive today?
Some lobe-finned fish still survive in the world’s waters today, including the appropriately named lungfish as well as the coelacanth.
Is a human a tetrapod?
The term tetrapod refers to four-limbed vertebrates, including humans. … Elpistostege, from the Late Devonian period of Canada, is now considered the closest fish to tetrapods (4-limbed land animals), which includes humans.
Which fish group is most closely linked to us?
Echinoderms are the most closely related phylum to the phylum Chordata, which includes many complex organisms such as humans.
Are humans fish from a Cladistic standpoint?
Most people agree that goldfish are an example of fish, and coelacanths are also an example of fish. But we humans (in fact all tetrapods–amphibians, reptiles, and mammals) shared a common ancestor with coelacanths more recently than either us or coelacanths shared a common ancestor with goldfish!
What animal did fish evolve from?
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. Pikaia had a primitive notochord, a structure that could have developed into a vertebral column later.
Are any fish smart?
“Fish are more intelligent than they appear. In many areas, such as memory, their cognitive powers match or exceed those of ‘higher’ vertebrates including non-human primates.” Fish’s long-term memories help them keep track of complex social relationships.
What was the first fish to walk on land?
First Land-Walking Fish Looks Like It Had ‘All-Wheel Drive’ : The Two-Way Fossils of Tiktaalik, which lived some 375 million years ago and is believed to be the first fish that walked on land, had more robust hindquarters than previously known.
What separates sharks from other fish?
But how is a shark different from other kinds of fish? Most other fish have skeletons made of bone. A shark’s skeleton is made of cartilage, a type of strong but flexible tissue. Most other fish are covered in smooth, flat scales.
Which animal does not have jaws?
Cyclostomes: Hagfish and Lampreys
In fact, they are the only two groups of extant vertebrates that lack jaws.