Hagfish Bottom dwellers in cold marine waters Unique: they don’t have vertebrae Unique: their body fluids have nearly the same ion concentration as sea water Lack jaws : within mouth are 2 movable plates & a rough tonguelike structure that it uses to pinch off chunks of flesh often burrow into the body of a dead fish thru gills, skin, or anus once inside, they eat the internal organs

Hagfish http://www.youtube.com/watch?v=bqk0mnMgwUQ http://www.youtube.com/watch?v=pmaal7Hf0WA

Lampreys Class Cephalaspidomorphi *3-17 years Found along Atlantic Coast of Europe & North America , western Mediterranean Sea, & Great Lakes About half of the species are free-living (non-parasitic) Other half are parasites as adults & feed on the blood/body fluids of other fishes SEE

Lamprey finds a suitable host & uses its disk-shaped mouth to attach Scrapes a hole in the host with its rough tongue & secretes a chemical that keeps the host’s blood from clotting After feeding, the lamprey drops off Host may recover, bleed to death, or die from infection

Lampreys http://www.youtube.com/watch?v=x-KJZ22-wTQ http://www.youtube.com/watch?v=eqoT8tcZq6k http://www.youtube.com/watch?v=iWtt-BUCaJg http://www.youtube.com/watch?v=CscE2XyrBFU&feature=fvsr http://www.youtube.com/watch?v=nQJFoA_6mJQ&feature=related LONG

CLASS CHONDRICHTHYES Cartilaginous fishes because of cartilage skeleton Sharks, rays, & skates Cartilage- flexible, lightweight material made of cells surrounded by tough fibers of protein Notochord of juveniles turns to cartilage in adults Tough skin is covered with dermal denticles (placoid scales)-makes them feel like sandpaper Breathe thru 5-7 gills Sharks and rays reproduce by passing sperm from male to female, male using modified fins called claspers Some species produce large egg cases while others produce live young

shark ray skate

Ray Skate give birth to live young (via ovoviviparity) pelvic fin with 1 lobe tail relatively slender to whip-like, usually with a saw-edged stinging spine midway along its length **BIGGEST DIFFERENCE IS IN BREEDING Skates give birth to young in eggcases – sometimes called mermaid’s purses (via oviparity) each pelvic fin divided into 2 lobes tail relatively stocky, without a stinging spine

Chondrichthyes http://www.youtube.com/watch?v=z3LnYqtjlVQ&feature=related sharks http://www.youtube.com/watch?v=NNG5l1K9jLk&feature=related

SUPERClass Osteichthyes Of 25,000 fish species, about 95% are bony fishes Group accounts for most of the vertebrates living in aquatic environment EXAMPLES: lungfishes, coelacanth, trout, salmon, perch, guppies, bass, herring, goldfish, eels, etc.

3 characteristics of bony fish BONE: Material is typically harder and heavier than cartilage LUNG or SWIM BLADDER: early bony fishes had lungs (internal respiratory organs in which gas is exchanged b/w air and blood - today most bony fishes have a swim bladder that controls buoyancy SCALES: protect the fish & reduce friction when swimming

2 main groups of bony fishes Class Sarcopterygii: lobe-finned fishes Have fleshy fins supported by a series of bones 2 groups exist today 6 species of coelocanths & 1 species of lungfish Lungfishes live in shallow tropical ponds that periodically dry up Coelocanths live deep in the ocean Coelocanth lungfish

Ray-finned Fishes Class Actinopterygii Contain majority of species of fish (96% of 25,000 species) Divided into 46 orders They have an upper jaw that consists of 2 bones & fins with bony spines (which differ from those with lobed-fins) Inhabit a wide range of habitats..salt & freshwater…shallow to great depths

Draw bony fish & label in your notes