1. North American Wildlife
Fish
North American Wildlife

3. Lets study some fish Ichthyology- The scientific study of fish
More then 30,000 species
Types of fish
Osteichthyes- bony fish
Chondrichthyes- cartilaginous fish
Agnatha- jawless fish

5. Importance of fish in the ecosystem
Fish form an important part of the food web in aquatic ecosystem, and can be either top predators, intermediate herbivores, or plankton eaters.
A variety of birds and other animals depend upon fish as their primary food source.
The presence or absence of individual species, as well as overall fish numbers can be an indicator of ecosystem health and can affect water clarity and water quality.
Fisheries form an important resource for food and recreation for humans as well.

6. Basic Fish Info
Ectotherms- exist at or near the temperature of their surroundings
No legs instead fins
No lungs instead gills
Scales
We eat them sometimes
We keep them as pets sometimes

7. Biological Magnification
Have any of you ever heard that fish contain mercury???
What is it? An increase in the concentration of a substance that occurs in the food chain
As we move up food chain more mass has to be consumed to get same energy
Chemicals, like DDT or mercury, that have been polluted into waters, accumulate at higher levels on the food chain.
Who is at the top of the food chain?
What fish should we avoid?

8. Fish Food Extremely important as a food source for humans
High in Omega 3 Fatty Acids- good for heart
14%-16% of animal protein consumed worldwide
Over 1 billion people rely on fish as their primary animal protein
Among the most common food allergies
Over-fishing can cause a collapse in the food chain

9. Egg laying
97% of fish are oviparous- eggs develop outside the mothers body
Normally fertilization occurs outside body (exceptions- some sharks, rays, and skates)
Spawn- when a female deposits her eggs or roe
Male will then fertilize by discharging milt or sperm

10. Schooling Many fish of the same species moving in harmonious patterns
Safety in numbers
Not to be confused with a shoal- any aggregate group of fish (variety of species)
Both benefit group members