Fish Form and Function

1. Fish Form and Function Why does it look like that?

2. The Basic Fish A Bony Fish

3. The Basic Shark A Cartilaginous Fish

4. The Fish Scales – Made from bone and look like shingles The Shark Scales or Dermal Denticles – tiny toothe like structures – smooth and feel like sandpaper Scales

5. Fins • Move, Stabilize and Protect • Paired – pectoral and pelvic • Unpaired – anal, caudal, and dorsal • Placement and purpose varies • Bony fish – visible supporting rays and spines • Cartilaginous – no visible support

6. Gills • Oxygen enters at gills • Found along the side of the head – Feathery in structure • Appear bright red when healthy • Sharks have 5-7 gill slits that allow water to pass out of the gill cavity • Bony fish gills covered by a bony plate – the operculum

7. Gills and “Breathing”

8. Eyes • Most well developed • Sharks – Pupils that dilate and constrict, eyelid that closes from the bottom up • Fish – Lack both

9. The Mouth Location and Size can determine food and ecosystem. Terminal – can chase and capture things or pick at things. Located on the front end Up-Pointing: long lower jaw & feeds near the surface.The mouth opening is toward the top of the head.

10. Sub-Terminal: on the underside of the head, usually feed on the bottom. Some fish have specialized mouths. The seahorse has a tiny mouth at the end of a straw-like snout that is used to "slurp"zooplankton. The Sharks’ mouth is located on the underside of its head.

11. Body Shapes Fusiform or streamlined - capable of swimming very fast, usually live in open water. Laterally compressed: usually do not swim rapidly, exceptionally maneuverable.

12. Depressed: flattened from top to bottom (like stingrays) live on the bottom. Eel-like: snake-like body shape Some fish fit into no categories, they tend to have protective outer coverings and are slow swimmers.

13. Crescent-shaped: Fish with crescent-shaped tails are fast swimmers and constantly on the move. Forked: Fish with forked tails are also fast swimmers, though they may not swim fast all of the time. The deeper the fork, the faster the fish can swim. Rounded: Fish with a rounded or flattened tail are generally slow moving, but are capable of short, accurate bursts of speed. Tails – indicate speed

14. Color • Red – Common color in fish – deep water or nocturnal • Countershading – Dark on top light on bottom • Disruptive coloration – camouflage • Eyespot – mimicry, spot usually near tail • Warning Coloration- advertise defense mechanism • Camouflage – blend into the background

15. Senses • Sight – Most have good sight. • Smell – nares are two blind sacs that detect odor. • Taste – Taste buds are in lining of mouth and gills, Barbels are “whiskers” that are covered with taste buds • Hearing – Inner ears are well developed and pick up sound waves through the fish’s body • Lateral Line – Feel movements in the water • Electricity – Some have special pores that detect electricity.

16. Several methods for getting around • Waves passing down the body • Flex the posterior (caudal) portion of the body • Flap pectoral fins and (sometimes) tail • Move just the tail

17. Getting Around