Biology Week 19 - Day 3 Chordates, Vertebrates & Fish

The Bony Fish

click to find the answer to today's question Do fish have eyelids?

The Class Osteichthyes: The Coelacanth, a lobe-finned fish

Lobe-finned fish link to an Internet Website

Lungfish link to an Internet Website Ray-finned fish link to an Internet Website

the key points to useful information on this page
Fish body specialization:
link to a local picture

Types of scales and body movement:link to a local webpage

Types of fins and the motion they produce:

Lateral line: link to an Internet Website

A row of scales with sensory depressions down each side of the fish.
This system detects vibrations in the water.
Chromatophores: structures containing pigment to provide color patterns.

No eyelids:

Most fish have large eyes to help gather light in dim surroundings.
In bright surroundings, this causes fish to seek shadows.
Gills: link to a local picture external tissue rich with blood vessels to exchange gases with the water.
Operculum - a hard plate on either side of the head that protects the gills and opens at the rear to allow water to flow through the mouth and over the gills.
Swim bladder: link to a local picture
A thin-walled sac along the top of the abdominal cavity containing a mixture of oxygen, carbon dioxide, and nitrogen obtained from the bloodstream.
The swim bladder usually produces neutral buoyancy, but some fish are able to adjust their buoyancy by slightly changing the amount of gas in the swim bladder.
Almost all fish have a swim bladder. Those without one, like sharks and freshwater darters, sink if they stop moving their fins.

Yes, fish can talk! link to an Internet Website

The circulatory system of simple vertebrates:

The nervous system of simple vertebrates: