Phylum - Chordata Characteristics - have a notochord and a dorsal nerve cord at some point in their life cycle. A dorsal nerve cord is a tube of nervous tissue just above the notochord. A notochord is a firm tissue mass along the dorsal side. Dorsal: top Ventral: underneath
Subphylum Urochordata Subphylum Urochordata: includes tunicates, colonial drifting salps, and larvacean. Tunicates pump water to filter feed. Salps are gelatinous free- floating. Larvaceans are tadpole-like planktonic organisms thought to resemble the theorized ancestor of vertebrates. Larvaceans
Subphylum Cephalochordata Subphylum Cephalochordata includes 25 species of lancelet. Small filter feeders resemble vertebrates, except they lack vertebrae.
Subphylum Vertebrata Subphylum Vertebrata: A notochord that has developed into a spinal cord protected by vertebrae (spine) and a head with a brain. Vertebrates consist of the most complex organisms.
Subphylum Vertebrata - Class: Agnatha Class Agnatha: jawless fish. Species include lampreys and hagfish. Represent the ancestor of bony fish / sharks. Lampreyshagfish Eddie and the Hagfish Hagfish lampreys
Chordates Review1.8 Dorsal5-2. Ventral3. Notochord4. Why are lampreys and hagfish important fish in evolution?5. What characteristics does phylum Chordata have?6. What animals are in subphylum Urochordata?7. What animals are in subphylum Cephalochordata?8. What are the characteristics of subphylum vertebrata?9. What animals are in class Agnatha?10. What happened to the notochord in vertebrates?
Class: Chondrichthyes FYI: During the Cambrian period (500 million yrs. Ago) the first of three gill arches on a jawless fish evolved into the first jaws. Jaws allowed vertebrates to become very successful predators.
Class: Chondrichthyes5 - 10 Class Chondrichthyes includes sharks, rays and skates. Sharks and rays share a basic anatomy. Characteristics - jawed fish, that lack a swim bladder, and have cartilaginous skeletons.
Class: Chondrichthyes5 - 11 Cartilage saves energy. Saving energy is one of the things that have made them successful predators. Sharks have a sense of smell that detects incredibly diluted substances. Sharks have a “conveyor belt” of multiple rows of teeth. The new teeth swing into place as old teeth wear out and fall away.
Class: Chondrichthyes Sharks and rays have lateral lines – that detect water motion and vibrations.Sharks and Rays – Teeth and Wings
Class: Chondrichthyes Unique to sharks & rays is electroreception – the ability to sense tiny electricity created by muscles and nerves.
Class: Chondrichthyes Sharks and rays have organs called ampullae of Lorenzini which you can see as visible pits near their snouts used to detect the electrical current.
Fewer, but more mature offspring. Most fertilize eggs internally. Males deposit sperm in the female via a pair of organs called claspers. Females lay egg cases in which the juveniles develop for up to six months.
Class: ChondrichthyesA few shark species are ovoviviparous – the eggs hatch within the mother’s body. They give birth to live young rather than egg cases..
Shark size ranges from hand-sized to the whale shark – the largest fish. Whale sharks can reach 14m/46 feet. Basking sharks can reach 10m/33 feet. Megamouth sharks can reach 6m/20 feet. All three are filter feeders that consume plankton. Planet in Peril Shark Finning Whale Shark
Chondrichthyes Review1. What type of animals are in class chondrichthyes?2. List four characteristics of sharks & rays.3. What is the ampullae of lorenzini for?4. What are lateral lines for?5. What is special about shark teeth?6. Electroreception7. Ovoviviparous8. Which gender of sharks has claspers?9. What are two ways sharks give birth?10. What is the largest fish in the world?
Sharks in Peril Many sharks are in5-19 danger of going extinct due to human activities. Sharks are typically not dangerous to humans – we don’t taste good to them.
Shark Cage DivingShark Cage Diving
Sharks in Peril1. Shark nets Shark Nets
Sharks in Peril2. Shark Fin Soup
Sharks in Peril3. Sport Fishing Shark Fishing TX
Rays5-24 Rays, skates and guitarfish Ray anatomy is suited to life on sandy bottoms or midwater. Adapted to midwater are the eagle ray and manta ray. Pectoral fins have become “wings” that stretch forward over the gills and are fused to the sides of the head.
Rays No longer need a tail for swimming, (the tail has become a defensive whip in some species.) Rays literally fly through the water. The largest rays are mantas with wingspans exceeding 8 meters (26 feet). The Secret World of Sharks and Rays Like the largest shark, the mantas feed on plankton.
Chondrichthyes Review - 21. What animals are in class chondrichthyes?2. What are two differences b/w fish and sharks/rays?3. What are lateral lines for?4. Electroreception5. What part of a shark’s body became the “wings” of rays?6. What is the tail of the ray used for?7. What is the largest ray?8. At what depth in the water do most rays live in?9. What do the largest rays feed on?
Sharks in Peril5-27 Sharks in Deep Trouble Yao Ming 姚明 Shark Fin Soup
HW: Essay – due in four days Title: Sharks in Peril Write an essay that includes the three topics listed below. Your essay should be persuasive in protecting the world’s sharks that are left. Typed, double space, Vocabulary will be checked. Shark nets Shark fin soup Shark sport fishing Introduction paragraph (1) Paragraph per topic discussed (3) Conclusion paragraph (1) 5 paragraphs all together (typed)
Class: Osteichthyes Characteristics: jawed fish with bone skeletons. Most have scales. Most control buoyancy using oxygen gas exchanged to and from blood circulation to a swim bladder. (This allows many species to hover nearly motionless in midwater.)
Class: Osteichthyes Most bony fish reproduce externally. The female lays her eggs, the male immediately fertilizes them. Produce a vast number of off-spring with only a few expected to survive to maturity.
Class: Osteichthyes Bony fish have lateral lines that detect water vibrations. Most open ocean and schooling fish have a torpedo-like streamlined shape for speed. This fusiform shape is spindle-like, slightly broader at the head and a V-shaped tail. This makes them fast swimmers.
Class: Osteichthyes Most open-ocean and schooling fish have a lighter underside and dark topside for concealment. Bony fish living in reefs and on the bottom use survival strategies more diverse and include concealment and armor instead of swimming. For this reason, you see far more diversity in color, shape, and size among reef and bottom fish.
Order: Clupeiformes Important in worldwide Herring fisheries. 1. Order Clupeiformes which includes herrings, pilchards, sa rdines, and anchovies. Unloading herring About one-quarter of all fish caught come from this order. Sardine Anchovy
Order: Gadiformes 2. Order Gadiformes includes cod, pollack, haddock, whitin gs, etc… A sixth of the world’s fish catch. Alaskan pollack, the haddock and whitings are important fisheries. Historically, worldwide fisheries have influenced politics and caused wars.
Salmon Important fish in California Return of the Salmon
Schools of Fish Do other animals do this? - Next slide
Flock of birds
Osteichthyes Review1. What does “osteo” mean?2. Swim Bladder3. Spawn4. Lateral line5. Open Ocean6. What are most fish color shading that live in the open ocean?7. What are two defenses reef fish use?8. What common fish belong in Clupeiformes?9. What common fish belong in Gadiformes?10. What are some concerns regarding salmon?