Sharks and Rays-Teeth and Wings Choose to view chapter section with a click on the section heading. Subphylum Vertebrata Sharks and Rays-Teeth and Wings Ray-Finned Fish-Half the World’s Vertebrates Marine Reptiles-Cold Blood and Warm Water Seabirds-At Flight Over and In the Ocean Marine Mammals-Warm Blood in Cold Water

Subphylum Vertebrata Subphylum Vertebrata Chapter 7 Pages 7-2 to 7-4

Subphylum Vertebrata Subphylum Vertebrata Chapter 7 Pages 7-2 to 7-4

Characteristics of Vertebrates Organisms in this subphylum: Dominate the upper levels of almost all food webs. Have a dorsal nerve cord that has developed into a spinal cord, protected by vertebrae. Have a head with a brain. Are complex, large, fast, and conspicuous organisms. Includes man. Subphylum Vertebrata Chapter 7 Page 7-2

Jawless Fish - The Living Ancestors of Sharks and Fish Jawless fish, the agnathans: Includes two classes Perromyzontida - the lampreys, and Myxini - the hagfish. May represent the ancestor of ray-finned fish and sharks. Scientists theorize that during the Cambrian period the first of three gill arches on a jawless fish evolved into the first jaws. Having jaws allowed vertebrates to become very successful predators. Subphylum Vertebrata Chapter 7 Pages 7-2 to 7-4

Sharks and Rays - Teeth and Wings Chapter 7 Pages 7-4 to 7-10

Characteristics of Sharks and Rays Sharks and Rays - Teeth and Wings Chapter 7 Page 7-4

Characteristics of Sharks and Rays Class Chondrichthyes includes sharks, rays and their close relatives. Sharks and rays don’t look similar on the outside, but share a basic anatomy that classifies them together. Sharks and rays are jawed fish, that lack a swim bladder, and have cartilaginous skeletons - they lack true bone. Sharks and Rays - Teeth and Wings Chapter 7 Page 7-4

Special Attributes of Sharks and Rays Are in the subclass Elasmobranchii. Are energy-efficient - don’t have to eat as much as other organisms the same size. Because of this they are successful predators. Have relatively simple cartilaginous skeletons - lighter than bone; saves energy. Store low-density oils for buoyancy. Have fins or wings that sit at angles and act like wings to provide lift. Skin contributes to saving energy. Have a “conveyor belt” of multiple rows of teeth. Sharks and Rays - Teeth and Wings Chapter 7 Pages 7-5 to 7-8

Special Attributes of Sharks and Rays Sharks and rays have other interesting characteristics: Both have lateral lines – lines of sensory hair along the length of the body that detect water motion and vibrations. Unique to elasmobranchs is electroreception – the ability to sense minute electricity created by muscles and nerves. 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. Sharks and Rays - Teeth and Wings Chapter 7 Pages 7-5 to 7-8

Special Attributes of Sharks and Rays Sharks and Rays - Teeth and Wings Chapter 7 Pages 7-5 to 7-8 Shark Anatomy

Special Attributes of Sharks and Rays Elasmobranchs differ in their reproductive strategy. Sharks and rays produce fewer, but more mature offspring. Most fertilize their eggs internally. The male deposits sperm in the female via a pair of copulatory organs called claspers found at the base of the pelvic fins. The female lays an egg case in which the juveniles develop for up to six months at which time one or more sharks or rays emerge. A few shark species are ovoviviparous – the eggs hatch within the mother’s body. They give birth to live young rather than egg cases. Sharks and Rays - Teeth and Wings Chapter 7 Pages 7-5 to 7-8

Special Attributes of Sharks and Rays Sharks and Rays - Teeth and Wings Chapter 7 Pages 7-5 to 7-8 Shark Egg Case From An Oviparous Species Shark Claspers On A Male

Special Attributes of Sharks and Rays Small and large sharks. Most sharks are not “man-eaters.” Many species of sharks are small. Shark size ranges from hand-sized to the whale shark – the largest fish in the ocean. Whale sharks can reach 14 meters (46 feet). Basking sharks can reach 10 meters (33 feet). Megamouth sharks can reach 6 meters (20 feet). All three of these large sharks are filter feeders that consume plankton. Sharks and Rays - Teeth and Wings Chapter 7 Pages 7-5 to 7-8

Special Attributes of Sharks and Rays Sharks and Rays - Teeth and Wings Chapter 7 Pages 7-5 to 7-8 Whale Shark The largest fish in the ocean. Horned Shark This California species is less than two feet long as an adult.

The Predators’ Predator The shark family Lamnidae are famous for their size and abilities. Family includes makos, porbeagles and great whites. These sharks: Are partially warm-blooded - large powerful muscles. Have efficient swimming shapes. Are at the top of the food web - an apex predator. Are in danger of extinction from man. Sharks and Rays - Teeth and Wings Chapter 7 Page 7-8 Mako Great White

Special Attributes of Rays Superorder Batidoidimorpha of subclass Elasmobranchii consists of the rays, which includes skates, mantas and guitarfish. Sharks and Rays - Teeth and Wings Chapter 7 Page 9 Manta Ray Stingrays

Special Attributes of Rays Have an anatomy well suited to life on sandy bottoms or midwater. Are specially adapted to life in midwater are the eagle ray and manta ray. Have pectoral fin “wings” that stretch forward over the gills and are fused to the sides of the head. Shoulder girdles are flattened and many bones are fused together for rigidity. Sharks and Rays - Teeth and Wings Chapter 7 Page 7-9

Special Attributes of Rays No longer need a tail for swimming, the tail has become a defensive whip in some species. Literally fly through the water. Include the mantas with wingspans exceeding 8 meters (26 feet). Mantas feed on plankton like many other larger organisms in the ocean. Sharks and Rays - Teeth and Wings Chapter 7 Page 7-9 Eagle Ray

Ray-Finned Fish - Half the World’s Vertebrates Chapter 7 Pages 7-11 to 7-16

Characteristics of Ray-Finned Fish Ray-Finned Fish - Half the World’s Vertebrates Chapter 7 Pages 7-11 to 7-13

Characteristics of Ray-Finned Fish Superclass Osteichthes and Class Actinopterygii are the “bony” or “ray-fin” fish. They are jawed fish with bone skeletons. Most have a swim bladder and scales. Most control buoyancy by adding or releasing gas to/from their swim bladder. They control the swim bladders with oxygen gas exchanged to and from blood circulation. Many have a special organ called the gas gland and the rete mirabile that take up gases from the bloodstream for the swim bladder. This allows many species to hover nearly motionless in midwater. Ray-Finned Fish - Half the World’s Vertebrates Chapter 7 Pages 7-11 to 7-13

Characteristics of Ray-Finned Fish Most ray-finned fish reproduce externally. The female lays her eggs, usually in vast numbers that can reach millions in some cases. The male immediately fertilizes them. Some species protect the eggs and juveniles, others leave larvae to fend for themselves as plankton. The strategy here is to produce a vast number of off-spring with only a few expected to survive to maturity. Contrast this with elasmobranchs. Ray-Finned Fish - Half the World’s Vertebrates Chapter 7 Pages 7-11 to 7-13

Characteristics of Ray-Finned Fish Ray-Finned Fish - Half the World’s Vertebrates Chapter 7 Pages 7-11 to 7-13 Basic Ray-Finned Fish Anatomy

Characteristics of Ray-Finned Fish Ray-finned fish have characteristics for life on the reef and for life in the open ocean: Ray-finned fish have lateral lines that detect water motion and vibrations. Most open ocean and schooling fish are relatively similar in shape and coloration. Fusiform shape - spindle form, broader at the head, and V-shaped tail. As in tuna. Countershaded for concealment - dark on top, light on the bottom. Ray-Finned Fish - Half the World’s Vertebrates Chapter 7 Pages 7-11 to 7-13

Characteristics of Ray-Finned Fish Ray-Finned Fish - Half the World’s Vertebrates Chapter 7 Pages 7-11 to 7-13 Fast Fish Tuna adapted to the open ocean life.

Characteristics of Ray-Finned Fish Ray-finned fish have adapted to many diverse bottom and reef habitats as well as midwater habitats. Survival strategies are likewise diverse - concealment, armor and fast swimming. For protection, reef and bottom species have far more diversity in color, shape, and size than midwater fish. Ray-Finned Fish - Half the World’s Vertebrates Chapter 7 Pages 7-11 to 7-13 Angelfish Tall narrow bodies. They can turn quickly and maneuver down into narrow cracks to hunt prey and escape predators.

Characteristics of Ray-Finned Fish Moray Eel Elongated, snake-like body for living in crevices and small caves Founder Flat body for living concealed on the bottom. Ray-Finned Fish - Half the World’s Vertebrates Chapter 7 Pages 7-11 to 7-13 Squirrel Fish A nocturnal fish with a red color that helps it remain concealed at night.

Special Attributes of Orders Clupeiformes and Gadiformes Two orders in class Actinopterygii have an important place in worldwide fisheries. Order Clupeiformes which includes herrings, pilchards, sardines, and anchovies. About one-quarter of all fish caught come from this order. Order Gadiformes which includes cods, pollocks, haddock, whitings, and their relatives. This order continues to produce about a sixth of the world’s fish catch. Alaskan pollack, the haddock and whitings have become important fisheries. Historically, worldwide fisheries have influenced politics and caused wars. Ray-Finned Fish - Half the World’s Vertebrates Chapter 7 Pages 7-14 to 7-15

Special Attributes of Orders Clupeiformes and Gadiformes Clupeiformes Anchovies Gadiformes Cod Ray-Finned Fish - Half the World’s Vertebrates Chapter 7 Pages 7-14 to 7-15 Gadiformes Haddock Gadiformes Pollock

Marine Reptiles - Cold Blood and Warm Water Chapter 7 Pages 7-16 to 7-19

Characteristics of Reptiles Marine Reptiles - Cold Blood and Warm Water Chapter 7 Page 7-16

Characteristics of Reptiles Organisms in class Reptilia mostly live on land or in freshwater. Relatively few live in the ocean. They have these characteristics in common: Are generally cold-blooded and have scales. Reproduce (most species) by laying internally fertilized eggs. Breathe air with lungs at all stages of their lives. Marine Reptiles - Cold Blood and Warm Water Chapter 7 Page 7-16

Special Attributes of Marine Crocodiles, Turtles, Snakes, and Lizards Three orders of reptiles having marine species are: Order Crocodilia – alligators, crocodiles, and caimans. Members of this order are semi-aquatic with most living in freshwater. Exception is the giant saltwater crocodile. Order Chelonia – turtles and tortoises. There are seven species of marine turtles – all live in relatively warm waters. Most are endangered. Order Squamata – snakes and lizards. 61 species of sea snake are true marine organisms. Only one lizard is a true marine reptile – the marine iguana. Marine Reptiles - Cold Blood and Warm Water Chapter 7 Pages 7-17 to 7-19

Special Attributes of Marine Crocodiles, Turtles, Snakes, and Lizards Order Chelonia – Marine Turtles Green sea turtle. Photo from Belize, Caribbean. Marine Reptiles - Cold Blood and Warm Water Chapter 7 Pages 7-17 to 7-19 Hawksbill turtle. Cayman Islands, Caribbean.

Special Attributes of Marine Crocodiles, Turtles, Snakes, and Lizards Order Chelonia – Marine Turtles Leatherback turtle fitted with a tracking transmitter. Marine Reptiles - Cold Blood and Warm Water Chapter 7 Pages 7-17 to 7-19 Nesting female sea turtle.

Special Attributes of Marine Crocodiles, Turtles, Snakes, and Lizards Order Squamata - Snakes and Lizards Sea snakes. True marine organisms; known for having the most toxic venom of any snake. Marine Reptiles - Cold Blood and Warm Water Chapter 7 Pages 7-17 to 7-19

A single species of marine iguanas, found on the Galapagos Islands. Special Attributes of Marine Crocodiles, Turtles, Snakes, and Lizards Order Squamata - Snakes and Lizards Marine Reptiles - Cold Blood and Warm Water Chapter 7 Pages 7-17 to 7-19 Marine iguanas. A single species of marine iguanas, found on the Galapagos Islands.

Seabirds - At Flight Over and In the Ocean Chapter 7 Pages 7-20 to 7-22

Characteristics of Birds Seabirds - At Flight Over and In the Ocean Chapter 7 Pages 7-20 to 7-21

Characteristics of Birds Birds are vertebrates in class Aves. They share several characteristics: Feathers, unique to this class. Forelimbs that are wings. A four-chambered heart and lay internally fertilized eggs. Marine birds are important to the marine ecosystem: They are predators that consume fish, crustaceans, and mollusks. In turn they are prey to marine mammals and sharks. They supply guano – a significant source of nutrients, specially organic nitrogen important to sea life. Seabirds - At Flight Over and In the Ocean Chapter 7 Pages 7-20 to 7-21

Characteristics of Birds Many species of birds exhibit related adaptations to an aquatic life: Webbed feet for swimming and floating on the surface. Bill adaptations suited to catching their marine prey, like the pelican’s pouch. The cormorant flies over water, and dives in it in pursuit of prey. Birds, like the albatross, have wings and flight characteristics adapted to long-duration flying over wide expanses of water. Seabirds - At Flight Over and In the Ocean Chapter 7 Pages 7-20 to 7-21

Special Attributes of Penguins Penguins, order Sphenisciformes, all live in the Southern hemisphere. Penguins make up about 80% of all Antarctic birds and by far outnumber even the massive marine mammal populations. Seabirds - At Flight Over and In the Ocean Chapter 7 Page 7-21 Emperor Penguins. Adapted to a totally marine existence.

Special Attributes of Penguins Penguins, order Sphenisciformes, all live in the Southern hemisphere. Penguins make up about 80% of all Antarctic birds and by far outnumber even the massive marine mammal populations. Not all species live in cold places. Penguins are found on the coasts of South America, Africa, Australia, New Zealand, and the nutrient-rich waters surrounding the Galapagos Islands near the equator, They cannot fly, but they’re as at home underwater as other birds are in the air. They: Spend as much as 75% of their time under water searching for food. Can reach depths of 100 meters (328 feet) and deeper. Seabirds - At Flight Over and In the Ocean Chapter 7 Page 7-21

Marine Mammals - Warm Blood in Cold Water Chapter 7 Pages 7-22 to 7-30

Characteristics of Marine Mammals Marine Mammals - Warm Blood in Cold Water Chapter 7 Pages 7-22 to 7-25

Characteristics of Marine Mammals All organisms in class Mammalia share these characteristics. They: Have hair on some part of the body. Nourish their young with milk provided by mammary glands. Are homeothermic (warm-blooded) with a constant internal temperature. Give birth to live young (majority of species). Marine Mammals - Warm Blood in Cold Water Chapter 7 Pages 7-22 to 7-25

Characteristics of Marine Mammals The marine environment poses FIVE main challenges to mammalian physiology: 1. Compared to living in air, life in water demands high oxygen consumption. Marine mammals meet this challenge by breathing air. 2. There is a need to dive holding their breath for reasonable periods. They: Use myoglobin, a protein, to bind reversibly with oxygen to make it available for use in metabolism. Use the mammalian diving reflex – is when diving pulse rate slows and blood flow diverts from the muscles to the heart and brain. Sink or glide underwater reducing oxygen use. Marine Mammals - Warm Blood in Cold Water Chapter 7 Pages 7-22 to 7-30

Characteristics of Marine Mammals 3. The water pressure and a need to equalize. Marine mammals’ lungs and sinuses are very flexible, allowing compression without pain or injury. Some dolphins and whales have lungs that engorge with blood thus offsetting the compressed space. 4. The challenge of easy movement through the dense medium of water. The use of streamlining and hydrodynamics helps with this. Marine Mammals - Warm Blood in Cold Water Chapter 7 Pages 7-22 to 7-25

Characteristics of Marine Mammals 5. The challenge of the senses. They need to hear, see, and smell underwater. Dolphins and whales use echolocation (natural sonar) to determine distance, size, density, and shape. Seals and sea lions have sensitive hearing and excellent underwater eyesight. They see poorly above water, but have a keen sense of smell. Marine Mammals - Warm Blood in Cold Water Chapter 7 Pages 7-22 to 7-25

Special Attributes of Seals and Sea Lions The seals and sea lions belong in order Pinnipedia. “True” Seals: don’t have ear flaps, rear flippers point backward and cannot rotate forward, out of water seals crawl on their stomachs. Sea Lions: have ear flaps, hind flippers rotate, can sit upright and run. Walrus: don’t have ear flaps, hind flippers rotate, can sit upright. Marine Mammals - Warm Blood in Cold Water Chapter 7 Pages 7-22 to 7-25

Special Attributes of Dolphins, Whales and Porpoises Whales, porpoises, and dolphins come from different families organized under the order Cetacea. Cetaceans are divided into two suborders: Suborder Mysticeti: a group of filter feeders made up of baleen whales. Suborder Odontoceti: a group of toothed whales made up of sperm whales, dolphins and porpoises. They are predators. Family Delphinidae: are the dolphins and orcas, one of the most varied and successful groups among the toothed whales. Most cetacea use echolocation and communicate by sound. Marine Mammals - Warm Blood in Cold Water Chapter 7 Pages 7-26 to 7-27

Special Attributes of Dolphins, Whales and Porpoises Relative sizes of the baleen whales in the suborder Mysticeti. Marine Mammals - Warm Blood in Cold Water Chapter 7 Pages 7-26 to 7-27

Special Attributes of Dolphins, Whales and Porpoises Relative size of toothed whales in the suborder Odontoceti. Marine Mammals - Warm Blood in Cold Water Chapter 7 Pages 7-26 to 7-27

Special Attributes of Dolphins, Whales and Porpoises Marine Mammals - Warm Blood in Cold Water Chapter 7 Pages 7-26 to 7-27 Bottlenose Dolphins Family Delphinidae Orca Killer Whale

Special Attributes of Dugongs and Manatees Dugongs and manatees (sometimes called sea cows) belong to order Sirenia, which has four species. All four are the only herbivorous marine mammals. Manatees are known for migrating to and from fresh- and saltwater environments. Relatives of the elephant. They are endangered. Marine Mammals - Warm Blood in Cold Water Chapter 7 Page 7-28

Marine Mammals and Human Interaction Human activities have endangered marine mammals and continue to do so. Whaling brought whales to the verge of extinction. Banned or greatly limited by international convention today, some species seem on the rise, others do not seem to be recovering. Marine Mammals - Warm Blood in Cold Water Chapter 7 Pages 7-28 to 7-29 Old-school whaling operation.

Marine Mammals and Human Interaction Human activities have endangered marine mammals and continue to do so. People have hunted seals for their fur and manatees for meat. Dolphins have been killed as bycatch in tuna fishing. Pollution and overfishing raise new threats. Because of their high metabolisms and energy demands, marine mammals require highly productive environments to survive. Marine Mammals - Warm Blood in Cold Water Chapter 7 Pages 7-28 to 7-29