Fish of Nova Scotia Introduction to the Fisheries

Fish are Special Come in all shapes, colors and sizes Come in all shapes, colors and sizes Lived on Earth before the dinosaurs Lived on Earth before the dinosaurs One of the most diverse and oldes groups of animals. One of the most diverse and oldes groups of animals.

What is a fish A fish: Has a backbone Has a backbone Is cold-blooded Is cold-blooded Breathes with gills Breathes with gills Lives in the water Lives in the water Has fins Has fins Most have scales Most have scales

Fish Facts The largest fish is a whale shark (>50ft) The largest fish is a whale shark (>50ft) The smallest fish is a goby (~1/2 inch) The smallest fish is a goby (~1/2 inch) Growth rings on scales help to determine the age of a fish; this is much like counting rings on a tree Growth rings on scales help to determine the age of a fish; this is much like counting rings on a tree The blue fin tuna is the fastest fish The blue fin tuna is the fastest fish The seahorse is the slowest fish The seahorse is the slowest fish

Fish Shapes Fish have 6 main body shapes: 1. Flat (rays, skates, flounder, sole) 2. Fusiform (sharks, salmon, barracuda, tuna) 3. Elongated (eels) 4. Compressed (butterfly fish, angelfish) 5. Round (Porcupine fish) 6. Ribbon (Cutlass)

Flat

Fusiform

Elongated

Compressed

Round

Cutlass

The Three Classes of Fish 1. Agnatha: Most primitive Most primitive No jaws No jaws Their mouth is like a hole in the head that lacks moveable parts Their mouth is like a hole in the head that lacks moveable parts Ex. Lamprey, hagfish Ex. Lamprey, hagfish

Chondrichthyes Fish whose skeletons are made of cartilage Fish whose skeletons are made of cartilage Sharks, rays, skates Sharks, rays, skates

Oseichthyes Bony fish – jaws and skeletons made of bones Bony fish – jaws and skeletons made of bones Most have scales and two sets of paired fins Most have scales and two sets of paired fins Most have a swim bladder for buoyancy Most have a swim bladder for buoyancy