Invertebrate Chordates

Transcription

1 Invertebrate Chordates Chapter Fishes And Invertebrate Chordates... Invertebrate Chordates Lancelets Filter feed and spend most of their time buried in the sand. Only 2 invertebrate chordates Tunicates (sea squirts) Interesting fact: They eat their own, which controls movement. Adults are sessile and no longer have a notochord or postanal tail Filter feeders Characteristics of Fishes Vertebrates Ectotherms Gills, Fins, and Scales Closed circulatory system 2 chambered heart and a one loop

2 Circulatory System of Fishes Closed One loop 2 chambered heart - receives blood from body - pumps blood to gills & body Oxygen in Water from mouth flows over gills Oxygen diffuses into blood vessels in gills Heart pumps oxygen-rich blood through arteries to body cells Cellular Respiration In which cell organelle does it take place? What is the equation? What is the most important product? Why is this product important to the organism? Carbon Dioxide out CO2 waste diffuses out of cells and into blood vessels. Blood carrying CO2 (oxygen-poor blood) moves through veins to the heart Heart pumps CO2 to gills where it is removed from blood

3 Fins Feeding Fins: thin membrane stretched over bony supports Used for movement and keeping them upright Or not... Reproduction Most fish perform external fertilization Some fishes, like sharks and guppies perform internal fertilization and give live birth Nervous and Sensory System External Fertilization Fishes have keen senses of touch, smell, taste, sight, (no ears, but can sense vibrations)

4 Jawless Fishes (Class: Agnatha) 3 Major groups of Fishes Fishes are categorized by: Mouth structure Type of Skeleton 3 groups are: Jawless Fishes Cartilaginous Fishes Bony Fishes 1st vertebrates on earth No Jaw and paired fins Circular mouth Smooth, scaleless skin Endoskeleton made of cartilage Cartilage is a connective tissue and its more flexible than bone Freshwater and marine habitats Only 2 Types of Agnatha Left! Hagfish Eel-like Feed on dead or dying fish Less than 1m in length ~40 species Lamprey Aggressive parasite Saliva acts as an anticoagulant ~41 species Lamprey Attack

5 Characteristics: Endoskeleton of Jaws w/ teeth Placoid scales (made of ) Internal fertilization Types of Cartilaginous fishes Sharks Skates Rays Sharks Rely on and to move water across gills Not picky eaters Keen sense of : Can and blood - even 1 drop in 115 L of water Poor Jagged arranged in rows Rays Flattened disc-like body Gills on side Wing-like pectoral fins Obtain by taking in water through small holes located behind their. Hunt fish, mollusks, and crustaceans living on the ocean floor Skates Similar to rays, except they.

6 Bony Fish (class: osteichthyes) Jaws Scales covers over the chamber. Endoskeleton made of. fertilization Bony plate-like for balance and buoyancy Freshwater and marine habitats % of all fish species! Swim Bladder Math A catfish weighs 2.5 kg and has a volume of 2.0 L. What is the density of the fish? If the density of water is 1 kg/l, will the fish sink or float? If the fish wants to move to the surface to eat a bug, what will it have to do to its swim bladder? Swim Bladder Internal, gas filled sac that helps with stability at different depths. Moving air into their swim bladder makes them. Releasing air from their swim bladder makes them. Swim Bladder Math If a fish weighs 30 kg and has a total volume of 15 L, will it sink or float? Assume water has a density of 1 kg/l. How much air (in L) will the fish have to add or remove from its swim bladder to obtain neutral buoyancy (neutral buoyancy is a condition in which the average density of an object is equal to the density of the fluid it is submerged in)?

7 Evolution from Fish to Amphibian