Vertebrate Biology Lecture 26.

Vertebrate Biology Lecture 26

Phylum Chordata Subphylum Urochordata Subphylum Cephalochordata
Vertebrata tunicates lancets Agnathans Fish Sharks tetrapods

Chordate Characteristics

Subphylum Urochordata tunicate

Subphylum Cephalochordata lancet

Hagfish Class Agnatha Subphylum Vertebrata What do they do?
For a long time, people thought of hagfish as scavengers and parasites, probably due to their habit or burrowing into dead or dying animals and eating them from the inside out. In fact, most of their diet is made up of marine worms and other invertebrates. Scientists used to think the hagfish looked primitive as a result of the loss of characteristics often associated with being a parasite. Now common belief is that hagfish just haven't needed to change for the last couple of hundred million years. Now that's a successful body plan and lifestyle! Another ability that had won fame for hagfish is the mass amounts of slime almost instantly secreted as a defense mechanism. Where are they found? Hagfish can be found in the chilly waters of the antitropical north and south. They tend to live on and in muddy sea floors in very dense groups (up to 15,000 in an area). Because females tend to produce large eggs in small numbers, their population sizes suggest a low death rate. One very useful trick hagfish have developed is the ability to tie themselves in knots, and be able to slide in and out of this knot. This can be used to escape predators, to clean themselves of slime, and to work their way into a carcass. This picture shows: A) knotting; this movement is used to clean slime off the body; B) escaping from capture using knotting, a very powerful motion; C) pulling on food by knotting They can also sneeze to unclog their nostrils of their own slime. Hagfish don't really have jaws. Instead they have two pairs of rasps on top of a tongue. They pull meat into their mouths with the tongue, then tear it off the prey with the rasps. Newly hatched hagfish look just like the adults, but have both male and female sex organs. When they mature, they will be either male or female, but have the ability to change from one to the other if the population structure demands it. Although hagfish have a partial skull, they have no back bone, so are not true vertebrates. What skeleton they do have is made of cartilage. How are they used by people? Yes, humans will find a way to exploit even these seemingly useless and repulsive animals. In Korea, almost 5 million pounds of hagfish meat are consumed each year. Hagfish skin is processed into "eelskin" boots, bags, wallets, purses, and other products. Overfishing in Asia has decimated their local hagfish stocks, so the Asian hagfish fishery has turned its eyes towards North America, where these "slime eels" are considered a worthless bycatch. It could mean a boost of over $2 million to the local fisheries, but care must be taken not to damage these stocks as well. Hagfish may not be pretty in most people's eyes, but they serve a purpose and are slow to reproduce. It would take them a long time to recover from over-harvesting. Who can tell what removing them from the local food web would do? Phylogenetics amongst species (for hard core scientists): There are about 20 species of hagfish divided into four genera (Myxine, Neomyxine, Paramyxine, and Eptatretus). These four groups make a sort of evolutionary continuum with regards to external traits. For example, the Myxine and Neomyxine are considered more advanced than the latter two for several reasons: They have a single pair of common external gill openings. The latter two have two minute separate gill openings (considered primitive). Paramyxine's openings are closer together than Eptatretus' so Paramyxine is considered more closely related to the first two. The eyes in Myxine and Neomyxine are smaller than those of the other two, suggesting a less primitive condition by an adaptation to the dark environment favoured my hagfish. Hagfish

Subphylum Vertebrata Class Agnatha lamprey

Subphylum Vertebrata Sharks, skates, rays Class Chondrichthyes

Class Chondrichthyes Characteristics Sharks, skates, rays, chimera
Posses jaws with teeth, cartilaginous skeleton, paired fins Scales (denticles) have same origin and composition as teeth Possesses 5-7 gills Spiral valve intestine Ureoosmotic strategy Lateral line No swim bladder Heterocercal tail Relatively unchanged (480 mybp)

Modern Sharks Feeding Types Planktivores Carnivores Parasites

planktivores Gill arch from basking shark

carnivores

Parasites Cookie cutter shark

Ampullae of Lorenzeni pores
The ampullae of Lorenzini are small vesicles that form part of an extensive subcutaneous sensory network system. These vesicles are found around the head of the shark. They detect weak magnetic fields at short ranges that are produced by other fishes. This enables the shark to locate prey that are buried in the sand or orient to nearby movement. Each ampulla is a bundle of sensory cells that are enervated by several nerve fibers. These fibers are enclosed in a jelly filled tubule which has a direct opening to the surface through a pore. These pores on the head of the shark are visible to the naked eye, and appear as dark spots in the photo of a porbeagle shark head below. Detects weak magnetic fields produced by other fish

Ampullae of Lorenzeni

Development Ovipary- eggs enclosed in capsule; eggs are laid and hatched outside the mother Ovovipary- give birth to young, eggs develop in uterus Vivipary- give birth to young, placental connection

Antagonistic displays

Attacks on Humans Most occur in near shore waters Follow food
Usually mistaken identification or territoriality Spear fishing

4 methods to minimize the risk of encountering a shark
stay away from harbor entrances avoid going in the water early in the morning and late at night stay in a large group of people if spearing fish, trail fish behind you Many shark attacks occur in nearshore waters, typically inshore of a sandbar where sharks may be confined at low tide. Sharks may also congregate along steep drop-offs, near channels or at river mouths, because their natural food items congregate there. There may be a number of reasons why sharks attack humans in these areas. Some attacks may be purely an inquisitive testing, some may be territorial responses, some could be due to unintentional interference by the victim in shark courtship activities, and some may be directly associated with feeding behaviors. Some scientists speculate that shark attacks on humans often are cases of mistaken identity, except in unusual situations such as when a sinking ship throws many people into the water. Whatever the cause, shark bites produce serious, sometimes life-threatening wounds. Whereas other sharks are likely to approach with caution, swimming around and poking the prey before attacking, the white shark often goes straight for the kill, relying on stealth to catch the victim off-guard. When feeding on prey at the surface, this shark rushes upward and, with an explosive splash, bites down on the unsuspecting victim. Although white sharks feed readily upon seals and sea lions, they often spit out birds, sea otters, and humans after the initial, albeit severe injury. Some shark experts have thought this indicated that human flesh or the neoprene of wetsuits was distasteful to the shark or that this reflected a "bite-and-release" attack strategy of the white shark, while others have speculated that these sharks only bit humans to defend their territories. Divers in wetsuits, surfers on short surfboards, and perhaps even kayakers may appear in silhouette like marine mammals, these sharks' natural prey, and some biologists have speculated on a connection. But if white sharks attack humans for food, the fact that nearly 75% of these attacks are non-fatal indicates that either the method of attack is allowing the human victim to escape, or we just don't taste right to them.

Shark Finning Fins drying in Cape Town, S. Africa

Shark Cartilage Cartilage- prevents growth of blood vessels in tissue
In theory, if it prevents the growth of blood vessels in tumors, the tumors would stop growing. Little solid evidence for ingesting over the counter capsules; they’re diluted with sugar or sterilized with ethylene oxide (a human carcinogen) Experiments with selacchi, derived from shark cartilage 90 g/day “+” results and FDA approved Also, harvesting sharks for unproven cure is detrimental to shark population

Characteristics Class Osteichthyes
Posses jaws with teeth, bony skeleton, paired fins 4 paired gill arches covered by operculum Intestine- simple, no spiral valve Swim bladder Lateral line Homocercal tail Scales- cycloid, ctenoid

Class Osteichthyes 680 species of fish in the islands' waters. About 30% of these fish are endemic to the area .

White mouthed morey Achilles tang trumpetfish Domino damsel
Trigger (Humu) White mouthed morey Porcupine Dwarf moray Achilles tang trumpetfish

Returns to water to breed Metamorphosis Some toxic
Class Amphibia Characteristics Cold blooded Returns to water to breed Metamorphosis Some toxic Estivation-dry and hot Hibernation- cold 3,500 species

Class Amphibia Mudpuppy (salamander) salamander newt Poison arrow frog
Rana cancrivora Coqui

Class Amphibia Metamorphosis

Increased UV radiation
Class Amphibia “Canaries in the coal mine” Habitat destruction Introduced species Pollution Pesticide use Diseases Over-harvesting Climate change Increased UV radiation Chilling new evidence suggests amphibians may be in worse shape than previously thought due to climate change. Further, the findings indicate that the 70 percent decline in amphibians over the past 35 years may have been exceeded by a sharp fall in reptile populations, even in otherwise pristine Costa Rican habitats. Ominously, the new research warns that protected areas strategies for biodiversity conservation will not be enough to stave off extinction. Frogs and their relatives are in big trouble. Writing in the Early Edition of the Proceedings of the National Academy of Sciences (PNAS), a team of researchers led by Steven M. Whitfield of Florida International University, found that amphibian and reptile populations declined by 75% since 1970 in the protected old-growth lowland rainforest of La Selva Biological Station in Costa Rica. The declines only occurred in primary forests -- neighboring abandoned cacao plantations did not suffer diminished populations. According to the Global Amphibian Assessment, a comprehensive status assessment of the world's amphibian species, one-third of the world's 5,918 known amphibian species are classified as threatened with extinction. Further, more than 120 species have likely gone extinct since 1980.

3 chambered heart (except crocks)
Class Reptilia Characteristics Cold blooded Have scales Amniotic egg Dry skin 3 chambered heart (except crocks) 6,500 species

Marine Reptiles Some reinvaded the oceans, but still breathe air:
Saltwater crocodile Sea snake Marine Reptiles (Sea Snakes) Marine Reptiles include sea snakes, saltwater crocodiles, marine iguanas and sea turtles. Sea snakes are a group of true snakes that have completely adapted their life-histories to live in the sea. Marine turtle Marine iguana

Sea Snakes Yellow- bellied sea snake Sea Snakes
Snakes are cold-blooded (poikilotherms). Consequently, their distributions are restricted to warm waters and sea snakes are only found in the Indo-Pacific region. There is concern that if a sea-level canal were constructed across Panama, they could become introduced to the Caribbean. Sea snakes inhabit estuaries, coral reef areas and the open sea and they are often found in large schooling groups. Normally, sea snakes are quite docile and donÕt pose a threat to humans. They have powerful venom which they use to incapacitate fishes or squid. Human fatalities have occurred and these are most common when the snakes wash up on beaches and humans handle the reptiles. They have few natural predators other than sharks, saltwater crocodiles and eagles. Yellow- bellied sea snake

Sea Snakes Diversity: Location: Habitat:
Laticodtidae- krates- 5 species (1 is fw in Solomon Islands) Hydrophidae- 54 different species All derived from Colubrid ancestor; colubrids evolved 40 mya; Laticotids evolved from colubrids 30 mya Location: Laticotids- live from east coast India to Japan and come to the tip of Cape York (Australia) Hydrophiids- found from south tip of Africa to India to South East Asian Islands to Japan to north half of Australia Habitat: Primarily tropical; coastal estuaries, coral reefs, open sea; 33-36oC

Sea Snakes Behavior: Often schooling in aggregations; Not aggressive but human fatalities have occurred Prey: Feed on small fish or squid, which are killed with powerful venom Predators (few): sharks, snapper, grouper, crabs, saltwater crocodiles, raptors; they descend to escape Venom: 2-10 times as toxic as that of a cobras

Sea Snakes Adaptations to life in the sea
Osmoregulation: skin is impermeable to salts; salts eliminated by sublingual gland Developing a flattened paddle-shaped tail and a laterally compressed body. Reduced metabolic rate and increased tolerance for low oxygen levels Lungs- greatly enlarged; hydrostatic organ Gaseous exchange - lungs and the skin. Developing salt excreting glands under the tongue. 2.Developing a flattened paddle-shaped tail and a laterally compressed body making it an efficient swimmer. 3.Reducing its metabolic rate. Sea snakes are capable of remaining submerged for up to 2 hours by decreasing its metabolic rate and developing an increased tolerance for low oxygen levels. After one breath at the surface, it can dive again. A sea snake also has valve-like flaps over its nostrils to stop water flowing into the lungs. 4.The lungs of sea snakes are greatly enlarged, extending to the base of the tail enabling a large volume of oxygen to be stored in the lungs. 5.Parts of the lung are believed to function as a hydrostatic organ regulating the snake's buoyancy. 6.Gaseous exchange occurs through both the lungs and the skin. Up to 22% of the oxygen is supplied from the sea water through the skin and all excess carbon dioxide is lost into the sea.

Sea Snakes Reproduction: Krates are oviparous and lay eggs on land
Hydrophiids are viviparous and produce young in the water Not much known about breeding However, olive sea snake breed in spring; seasonal courtship displays Banded sea krates forming mating group Olive Sea Snake

Saltwater crocodiles Largest living crocodilians: 6-7 m long
Eggs laid and incubated on land Tropical and subtropical Saltwater Crocodiles Saltwater crocodiles are the largest of living crocodilians and adults can reach 6-7 m in length. These seagoing animals may travel thousands of miles in the ocean. They are wide-ranging and may move into freshwater areas as well. They havenÕt entirely left land and must return to lay their eggs which are incubated in a terrestrial nest. Their poikilothermic nature means that their distributions are limited to warm areas. Diets include fishes, invertebrates and vertebrates.

Marine Iguanas Endemic to Galapagos islands
Herbivorous: graze on seaweeds Salt-glands on nose to eliminate excess salt Recently observed feeding on land for first time They return to land to escape predators. Marine Iguanas These are the only marine lizards and they are endemic to the Galapagos Islands off Ecuador. Marine iguanas have flattened tails that assist them in swimming and they have adapted to an aquatic life. Their primary diet are algae that encrust the rocks around the islands. Iguanas dive to feed on the algae and in the process, their bodies undergo substantial cooling. After diving and feeding bouts, they must warm themselves on land to raise their body temperature. During feeding they accumulate a lot of salt that is excreted via specialized salt-glands on their noses. Recently, iguanas have been observed feeding on terrestrial vegetation. The stresses of El Ni–os may have driven them to forage ashore.

Marine Turtles (Honu)

Anatomy Dorsal shell = carapace Ventral shell = plastron
Head does not retract carapace plastron

Anatomy Female Male

Adaptation to salt water
Lacrimal glands

Egg tooth- used to chip away at shell
Group effort to get out of nest- emerge at night (safer) and head towards brightest light Artificial lights- confuse hatchlings Turtle nest Cross section

Predators

Factors Affecting Green Sea Turtle Population
Hawaii nesting females French Frigate Shoals in the Northwest Hawaiian chain Hunters Fisheries Marine Debris Coastal Development and Habitat Degradation Fibropapilloma

Commercial Value Meat Eggs- nearly forbidden in all countries
with nesting beaches Soup Jewelry Leather Convention on International Trade in Endangered Species (CITES): turtle commerce prohibited in countries that signed agreement

Protection and Management
Law enforcement- in Hawaii, turtles protected under Endangered Species Act Riding or harassing- $100,000 fine + prison time Bringing turtle products into Hawaii- $20,000 + prison time

Increase sea turtle populations: Ranching- eggs or hatchlings from wild populations Farming- originally from wild populations, for breeding stock

Fishing regulations- Shrimp Trawlers - incidental catch by commercial shrimp fish nets: drowned 10,000 turtles each year Drift nets, gill nets Turtle Excluder Device (TED)

Marine Debris- plastic bags, soda can plastic rings, fishing line, oil and tar
Costal development and habitat degradation- noise, light, beach obstructions- affect nesting habitat

Fibropapilloma- virus in Green turtles
Affects ability to feed, see, move about, or breath May be due to pollutants, blood parasites, or habitat change Kaneohe Bay (1991)- >50% infected

Turtle Excluder Device

Warm blooded Feathers and wings Hollow bones Horny bill
Class Aves Characteristics Warm blooded Feathers and wings Hollow bones Horny bill Lungs have air sacks Hard egg shell

Class Aves

Warm blooded Have fur or hair Suckle young 3 middle ear bones
Class Mammalia Characteristics Warm blooded Have fur or hair Suckle young 3 middle ear bones A Guide to characteristics of Class Mammalia The Class Mammalia is well represented in Southern Africa. There are 293 species of land mammals and 37 species of marine mammals in the Southern African subregion. That is 330 of the around 5000 mammal species found on Earth! Class Mammalia -- all mammals share three characteristics not found in other animals: 3 middle ear bones; hair; and the production of milk by modified sweat glands called mammary glands. Mammals hear sounds after they are transmitted from the outside world to their inner ears by a chain of three bones, the malleus, incus, and stapes. Two of these, the malleus and incus, are derived from bones involved in jaw articulation in most other vertebrates. Mammals have hair. Adults of some species lose most of their hair, but hair is present at least during some phase of the ontogeny of all species. Mammalian hair, made of a protein called keratin, serves at least four functions. First, it slows the exchange of heat with the environment (insulation). Second, specialized hairs (whiskers or "vibrissae") have a sensory function, letting the owner know when it is in contact with an object in its external environment. These hairs are often richly innervated and well-supplied with muscles that control their position. Third, through their color and pattern, hairs affect the appearance of a mammal. They may serve to camouflage, to announce the presence of especially good defense systems (for example, the conspicuous color pattern of a skunk is a warning to predators), or to communicate social information (for example, threats, such as the erect hair on the back of a wolf; sex, such as the different colors of male and female capuchin monkeys; presence of danger, such as the white underside of the tail of a whitetailed deer). Fourth, hair provides some protection, either simply by providing an additional protective layer (against abrasion or sunburn, for example) or by taking on the form of dangerous spines that deter predators (porcupines, spiny rats, others). Mammals feed their newborn young with milk, a substance rich in fats and protein that is produced by modified sweat glands called mammary glands. These glands, which take a variety of shapes, are usually located on the ventral surface of females along paths that run from the chest region to the groin. They vary in number from two (one right, one left, as in humans) to a dozen or more. Other characteristics found in most mammals include highly differentiated teeth; teeth are replaced just once during an individual's life (this condition is called diphyodonty, and the first set is called "milk teeth); a lower jaw made up of a single bone, the dentary; four-chambered hearts, a secondary palate separating air and food passages in the mouth; a muscular diaphragm separating thoracic and abdominal cavities; highly developed brain; endothermy and homeothermy; separate sexes with the sex of an embryo being determined by the presence of a Y or 2 X chromosomes; and internal fertilization. The Class Mammalia includes around 5000 species placed in 26 orders (systematists do not yet agree on the exact number or on how some orders are related to others). Mammals can be found in all continents and seas. In part because of their high metabolic rates (associated with homeothermy and endothermy), they often play an ecological role that seems disproportionately large compared to their numerical abundance. Subclass Prototheria - Not represented in southern Africa Order Monotremata -- Monotremes: platypus and echidnas Subclass Metatheria (marsupials) - Not represented in southern Africa Order Didelphimorphia Order Paucituberculata Order Microbiotheria Order Dasyuromorphia Order Peramelemorphia Order Notoryctemorphia Order Diprotodontia Subclass Eutheria (placentals) Order Insectivora -- Insectivores: shrews, moles, hedgehogs, tenrecs, etc. Order Macroscelidea -- elephant shrews Order Scandentia -- tree shrews Order Dermoptera -- colugos Order Chiroptera --bats Order Primates --primates Order Xenarthra -- edentates; sloths, armadillos and anteaters Order Pholidota -- pangolins Order Lagomorpha -- rabbits and pikas Order Rodentia -- rodents Order Cetacea -- whales, dolphins, and porpoises Order Carnivora -- carnivores Order Tubulidentata -- aardvark Order Proboscidea -- elephants Order Hyracoidea -- hyraxes Order Sirenia -- dugongs and manatees Order Perissodactyla -- horses, rhinos, tapirs Order Artiodactyla -- antelope, giraffe, camels, pigs, hippos, etc.

Protheria- echidna & platypus Metatheria- marsupial
Class Mammalia Subclasses Protheria- echidna & platypus Metatheria- marsupial Eutheria- true mammals A Guide to characteristics of Class Mammalia The Class Mammalia is well represented in Southern Africa. There are 293 species of land mammals and 37 species of marine mammals in the Southern African subregion. That is 330 of the around 5000 mammal species found on Earth! Class Mammalia -- all mammals share three characteristics not found in other animals: 3 middle ear bones; hair; and the production of milk by modified sweat glands called mammary glands. Mammals hear sounds after they are transmitted from the outside world to their inner ears by a chain of three bones, the malleus, incus, and stapes. Two of these, the malleus and incus, are derived from bones involved in jaw articulation in most other vertebrates. Mammals have hair. Adults of some species lose most of their hair, but hair is present at least during some phase of the ontogeny of all species. Mammalian hair, made of a protein called keratin, serves at least four functions. First, it slows the exchange of heat with the environment (insulation). Second, specialized hairs (whiskers or "vibrissae") have a sensory function, letting the owner know when it is in contact with an object in its external environment. These hairs are often richly innervated and well-supplied with muscles that control their position. Third, through their color and pattern, hairs affect the appearance of a mammal. They may serve to camouflage, to announce the presence of especially good defense systems (for example, the conspicuous color pattern of a skunk is a warning to predators), or to communicate social information (for example, threats, such as the erect hair on the back of a wolf; sex, such as the different colors of male and female capuchin monkeys; presence of danger, such as the white underside of the tail of a whitetailed deer). Fourth, hair provides some protection, either simply by providing an additional protective layer (against abrasion or sunburn, for example) or by taking on the form of dangerous spines that deter predators (porcupines, spiny rats, others). Mammals feed their newborn young with milk, a substance rich in fats and protein that is produced by modified sweat glands called mammary glands. These glands, which take a variety of shapes, are usually located on the ventral surface of females along paths that run from the chest region to the groin. They vary in number from two (one right, one left, as in humans) to a dozen or more. Other characteristics found in most mammals include highly differentiated teeth; teeth are replaced just once during an individual's life (this condition is called diphyodonty, and the first set is called "milk teeth); a lower jaw made up of a single bone, the dentary; four-chambered hearts, a secondary palate separating air and food passages in the mouth; a muscular diaphragm separating thoracic and abdominal cavities; highly developed brain; endothermy and homeothermy; separate sexes with the sex of an embryo being determined by the presence of a Y or 2 X chromosomes; and internal fertilization. The Class Mammalia includes around 5000 species placed in 26 orders (systematists do not yet agree on the exact number or on how some orders are related to others). Mammals can be found in all continents and seas. In part because of their high metabolic rates (associated with homeothermy and endothermy), they often play an ecological role that seems disproportionately large compared to their numerical abundance. Subclass Prototheria - Not represented in southern Africa Order Monotremata -- Monotremes: platypus and echidnas Subclass Metatheria (marsupials) - Not represented in southern Africa Order Didelphimorphia Order Paucituberculata Order Microbiotheria Order Dasyuromorphia Order Peramelemorphia Order Notoryctemorphia Order Diprotodontia Subclass Eutheria (placentals) Order Insectivora -- Insectivores: shrews, moles, hedgehogs, tenrecs, etc. Order Macroscelidea -- elephant shrews Order Scandentia -- tree shrews Order Dermoptera -- colugos Order Chiroptera --bats Order Primates --primates Order Xenarthra -- edentates; sloths, armadillos and anteaters Order Pholidota -- pangolins Order Lagomorpha -- rabbits and pikas Order Rodentia -- rodents Order Cetacea -- whales, dolphins, and porpoises Order Carnivora -- carnivores Order Tubulidentata -- aardvark Order Proboscidea -- elephants Order Hyracoidea -- hyraxes Order Sirenia -- dugongs and manatees Order Perissodactyla -- horses, rhinos, tapirs Order Artiodactyla -- antelope, giraffe, camels, pigs, hippos, etc.

Class Mammalia Whales & Dolphins Polar bear Sea otter Seals & sealions manatee Dugong

Marine mammals: Order Sirenia
Sirenian characteristics: Large body size Sparse hair all over body Vegetarians Toenails (on manatees only) Includes: Manatees Dugongs

Marine mammals: Order Carnivora
All members of order Carnivora have prominent canine teeth Includes: Sea otters Polar bears Pinnipeds (flipper-footed) Walrus Seals Sea lions/fur seals Hawaiian Monk Seal

Sea Otter Enhydra lutris Native to north Pacific 394,000 hairs/cm2
No blubber Female 45 lbs; Male 65lbs Diet: Sea urchins, abalone, mussels, clams, crabs, snails and about 40 other marine species. Uses tools Dives to 330 ft Rests in coastal kelp forests STATUS: California, or southern, sea otters are listed as "threatened" under the federal Endangered Species Act (ESA) and "fully protected" under California state law. No other U.S. otter population is currently listed under the ESA. In 2003, there is a push to list a stock of the Alaskan sea otters, or northern sea otters, as "endangered" under the ESA. In Canada , the otter population in British Columbia is classified as "threatened" by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). All of the otters in the U.S. are protected under the U.S. Marine Mammal Protection Act (MMPA). DESCRIPTION: The sea otter has the thickest fur in the animal kingdom. Unlike other marine mammals, the sea otter does not have a layer of blubber (fat) to help keep it warm. If an otter's fur gets coated with oil or any other substance, it can easily die from cold and exposure. SIZE: The sea otter is the largest member of the weasel family. Southern sea otters typically reach about four feet in length. Females average 45 pounds, while males average 65 pounds. Northern sea otters can reach up to 100 pounds. POPULATION: Today there are about 2,500 southern sea otters off the coast of California. There are between 27,500 and 52,500 northern sea otters residing in Alaska, Canada and Washington. There are approximately 15,000 in Russia. Two hundred years ago, demand for the otter's pelt nearly led to its extinction. LIFESPAN: Male sea otters live an average of ten to 15 years, while female sea otters live an average of 15 to 20 years. RANGE: The sea otter?s historic range stretched from Japan, along the coast of Siberia and the Aleutian Chain and down the Alaska, British Columbia, Washington, Oregon and California coast to Baja California. HABITAT:Shallow coastal waters of the northern Pacific. FOOD:Sea urchins, abalone, mussels, clams, crabs, snails and about 40 other marine species. BEHAVIOR: Sea otters are the only mammals other than primates known to use tools. Otters use small rocks or other objects to pry prey from rocks and to hammer or pry open their food. They can dive up to 330 feet when foraging for food. Otters rest in coastal kelp forests, often draping the kelp over their bodies to keep from drifting away. OFFSPRING: Sea otters breed throughout the year. Females give birth to one pup after a gestation period of six to eight months. THREATS: Oil spills, habitat loss, disease, gill net entanglement and conflict with shellfish fisheries. PROTECTION: *CITES, Appendix I, Marine Mammal Protection Act, Endangered Species Act *Convention on International The Sea Otter (Enhydra lutris) is a large otter native to the North Pacific, from northern Japan and Kamchatka east across the Aleutian Islands south to California. The heaviest of the otters, Sea Otters are the only species within the genus Enhydra. Hunted extensively for their luxurious fur—the densest of all mammals with up to 394,000 hairs per square centimeter— from 1741 onwards, sea otter populations were greatly reduced to the point of extermination in many parts of their historic range. By 1911 the world population was estimated to be just 1,000-2,000 individuals in 13 colonies. Its estimated that a half million to a million otters were killed over time and over hunted and the population is thought to have been 150,000 to 300,000 historically before the years of the great hunt. Although several subspecies are still endangered, the otters have since been legally protected, and reintroduction efforts have shown positive results in some areas.

Polar Bear Ursa maritimus
United States, Canada, Russia, Greenland and on the Arctic islands of Norway Male: 10 feet tall and weigh over 1400 lbs Female: seven feet and weigh 650 lbs wild polar bears live up to age 25. Not federally listed as endangered or threatened. The International Union for Conservation of Nature (IUCN), Polar Bear Specialist Group lists most populations as "stable." DESCRIPTION: The polar bear rivals the Kodiak bear as the largest four-footed carnivore on Earth and can live up to 25 years. Although the polar bear?s coat appears white, each individual hair is actually a clear hollow tube that channels the sun?s energy directly to the bear?s skin and helps it stay warm. The polar bear?s entire body is furred, even the bottom of its paws. That helps prevent bears from slipping on the ice. The polar bear is classified as a marine mammal. Its feet are partially webbed for swimming, and its fur is water-repellent. A formidable predator, it has extremely sharp claws. SIZE: Males are 8 to 11 feet long and weigh 500 to 1,100 pounds but can reach as much as 1,500 pounds. Females are smaller, measuring 6 to 8 feet long, and weigh from 350 to 600 pounds, occasionally reaching 700 pounds. POPULATION: Worldwide there are thought to be 22,000-27,000 polar bears in 19 separate populations. They can be found in the United States, Canada, Russia, Greenland and on the Arctic islands of Norway. There are estimated to be about 3,000 to 5,000 polar bears in Alaska. RANGE:Polar bears are found throughout the Arctic and are the most nomadic of all bear species. They travel an average of 5,500 miles a year or 15 miles a day. In the United States, polar bears are located in two Alaskan populations: the Chukchi/Bering Seas of western Alaska and the Beaufort Sea off northern Alaska. HABITAT: The entire circumpolar Arctic region is polar bear habitat. They are equally comfortable in the water and on land. Polar bears can be found on pack ice, coastal islands, coastlines and even out in Arctic waters. They are exceptional swimmers and have been observed in the sea more than 100 miles from the nearest land or pack ice. FOOD: Polar bears are strictly carnivores and feed or scavenge only meat. Their primary prey is the ringed seal though they also take bearded, harp and hooded seals and the occasional walrus youngster. They will also scavenge walrus and whale carcasses. That sometimes results in temporary aggregations of polar bears at such sites. Other species, such as the Arctic fox, rely entirely upon "polar bear left-overs" after the bears have eaten their fill of seal skin and blubber, leaving the remaining meat for such scavengers. BEHAVIOR: The two main focuses of this solitary creature's life are to conserve energy and to hunt. Only pregnant females dig dens and hibernate in the traditional sense for extended periods. The other bears may enter into what is referred to as "walking hibernation" where they remain active and continue to hunt and feed, even though some of their metabolic processes may slow (decreased heart rates, respiration, lowered temperatures, etc.). Polar bears depend mostly on their sense of smell to determine the location of prey. Their white coats make great camouflage for hunting seals, and they will wait patiently for hours next to a seal?s air hole waiting for the seal to take a breath. Once the seal arrives, the polar bear will use its immense strength and sharp claws to clutch the seal and drag it through the small blowhole. OFFSPRING: Females are able to breed at the age of five years. They dig dens either on the coastal mainland or out on the drifting pack ice in late October or early November, and then remain denned until the next spring. An average of two cubs are born, each weighing about 1 pound at birth and growing to about 15 pounds by the time they emerge in the spring. The cubs have much to learn and usually remain with their mothers for more than two years. THREATS: The primary threat facing polar bears today may be global warming. Scientists have already documented measurable effects in the body sizes and reproductive success of bears at Hudson?s Bay. This southern-most population of polar bears has adapted to an ice-free summer by moving onshore at Churchill, Manitoba, and fasting through the short summer season until freeze-up occurs, and the bears can return to the ice. Global warming has resulted in prolonged ice-free periods, and the polar bears are left stranded onshore for longer and longer periods. Break-up in the spring occurs an average of days earlier than 20 years ago and was four weeks earlier in Scientists estimate that for every week of delay in freeze-up, polar bears lose at least 22 pounds of critical fat reserves. Pregnant females are losing so much weight that they fail to produce enough milk for their cubs, which then suffer increased mortality. Once females fail to attain a minimum weight they won?t give birth at all, and scientists can already document a 15 percent drop in birth rates. Another globally produced impact to polar bears are chemical pollutants that find their way into the cold Arctic ecosystems and then never disappear. Such chemicals as PCB?s (polychlorinated biphenyls), banned from the U.S. plastics industry since the 1970s, concentrate in the blubber of prey species that are then eaten by the bears. Such concentrations of these and other toxins are linked to immune deficiencies and generally reduced fitness in some polar bears. The third threat of note is the proposed oil and gas development on the Arctic National Wildlife Refuge in northeastern Alaska. This is the most important onshore denning habitat for polar bears in the United States. About half of the bears from the Beaufort Sea population den onshore, and half of these select the refuge?s coastal plain. This is the very place proposed for oil exploration. Both the seismic exploration phase and an eventual oil extraction phase could introduce serious disturbances that may result in den abandonment and death of the offspring. PROTECTION: CITES* Appendix II, U.S. Marine Mammal Protection Act, Agreement on the Conservation of Polar Bears. Good swimmers Thick blubber Thick fur

Pinnipeds Hawaiian Monk Seal Family Phocidae Walrus Sea Lion
Family Odobenidae Family Otariidae

Biology and Natural History
Order Pinniped (seals, sea lions, & walruses) Family Phocidae- true, earless seals Family Otariidae- eared seals and sea lions Family Odobenidae- walruses 34 known species Evolved 20 mya from Order Carnivora (ancestors of dogs and bears) Differ in possession of external ears and mode of locomotion

Differences between seals and sea lions/fur seals

Hind flippers propel them while swimming Front flippers act as rudders
Hawaiian Monk Seal Family Phocidae Lack external ears Hind flippers propel them while swimming Front flippers act as rudders Travel on land is difficult (wiggle)

Front flippers propel animal when swimming
Sea Lion Family Otariidae Eared seals Front flippers propel animal when swimming Rear flippers act as rudders Fairly mobile on land

Paddle with front flippers Rear flippers act as a rudder
Walrus Family Odobenidae Found in Arctic region Lack external ears Paddle with front flippers Rear flippers act as a rudder Fairly mobile on land

Marine mammals: Order Cetacea
Cetacean characteristics: Blowholes on top of skull Skull telescoped (streamlined shape) Very few hairs Includes: Whales, dolphins, and porpoises

Marine mammals: Order Cetacea

Two suborders of order Cetacea
(55 mya- entered sea) Suborder Odontoceti (toothed whales) Echolocate (send sound through water) Includes killer whale, sperm whale, dolphins, porpoises, and many others Suborder Mysticeti (baleen whales) Have rows of baleen plates instead of teeth Includes blue whale, finback whale, humpback whale, gray whale, and many others

Differences between dolphins and porpoises
Dolphins have: An elongated snout (rostrum) A sickle-shaped (falcate) dorsal fin Conical-shaped teeth Killer whale jawbone

Differences between dolphins and porpoises
Porpoises have: A blunt snout (rostrum) A triangle-shaped dorsal fin Spade-shaped teeth

Echolcation - the location of objects by their echos - is a highly specialized faculty that enables dolphins to explore their environment and search out their prey in a watery world where sight is often of little use. As sound travels four and a half times faster in water than in air, the dolphin's brain must be extremely well adapted in order to make a rapid analysis of the complicated information provided by the echoes. Although the ability to echolcate has only been proven experimentally for a few odontocete species, the anatomical evidence - the presence of the melon, nasal sacs and specialized skull structures - suggests that all dolphins have this ability. The dolphin is able to generate sound in the form of clicks, within its nasal sacs, situated behind the melon. The frequency of this click is higher than that of the sounds used for communication and differs between species. The melon acts as a lens whi ch focuses the sound into a narrow beam that is projected in front of the animal. When the sound strikes an object, some of the energy of the soundwave is reflected back towards the dolphin. It would appear that the panbone in the dolphin's lower jaw receives the echo, and the fatty tissue behind it transmits the sound to the middle e ar and thence to the brain. It has recently been suggested that the teeth of the dolphin, and the mandibular nerve that runs through the jawbone may transmit additional information to the dolphin's brain. As soon as an echo is received, the dolphin generates another click. The time lapse between click and echo enables the dolphin to evaluate the distance between it and the object; the varying strength of the signal as it is received on the two sides of th e dolphin's head enable it to evaluate direction. By continuously emitting clicks and receiving echoes in theis way, the dolphin can track objects and home in on them. The echolocation system of the dolphin is extremely sensitive and complex. Using only its acoustic senses, a bottlenose dolphin can discriminate between practically identical objects which differ by ten per cent or less in volume or surface area. It can do this in a noisy environment, can whistle and echolocate at the same time, and echolocate on near and distant targets simultaneously - feats which leave human sonar experts gasping

Deepest Diver (3km~1.5 miles)

Mysticeti: The baleen whales
Mysticeti whales have baleen instead of teeth Baleen plates: Hang as parallel rows from the upper jaw Are made of keratin Are used as a strainer to capture zooplankton Allows baleen whales to eat krill and small fish by the ton

Baleen

Types of baleen whales Baleen whales include three families:
Gray whale (a bottom-feeder with short baleen) Rorqual whales (medium-sized baleen) Balaenopterids (blue whales, finback whales, and other large whales ) Megapterids (humpback whales) Right whales (surface skimmers with long baleen)

Whale Migration

Whale Carcass Removal I am absolutely not making this incident up; in fact I have it all on videotape. The tape is from a local TV news show in Oregon, which sent a reporter out to cover the removal of 45-foot, eight-ton dead whale that washed up on the beach. The responsibility for getting rid of the carcass was placed with the Oregon State Highway Division, apparently on the theory that highways and whales are very similar in the sense that both are large objects. So anyway, the highway engineers hit upon a plan (remember, I am not making this up) to blow up the whale with dynamite. The thinking was that the whale would be blown into small pieces, which would then be eaten by seagulls and fish. That would be that--a textbook whale removal. So they moved the spectators back up the beach, put a half-ton of dynamite next to the whale and set it off. What follows, on the videotape, is one of the most priceless events in the history of the universe. First you see the whale carcass disappear in a huge blast of smoke and flame. Then you hear the happy spectators shouting "Yayy!" and "Whee!" Then, suddenly, the crowd's tone changes. You hear a new sound like "splud, splap," and you hear a woman's voice shouting "Here come pieces of...OH MY GOD!" Something smears the camera lens. Later, the reporter explains: "The humor of the entire situation suddenly gave way to a run for survival as huge chunks of whale blubber rained down everywhere.“ One piece caved in the roof of a car parked more than a quarter of a mile away!! Remaining on the beach were several large rotting whale sections the size of condominiums... Posted on: Saturday, June 15, 2002 Removal of carcass a whale of a task By Mike Gordon Advertiser Staff Writer State and city officials are used to removing things that wash up on island beaches, but two tons of smelly, decomposing whale carcass was a challenge yesterday. The dead sperm whale — what's left of it, anyway — floated in on Thursday night's high tide, coming to rest at Kualoa on a sliver of beach within sniffing distance of Kamehameha Highway, just north of the ruins of the sugar mill smoke stack at Kualoa Ranch. Normally, the city takes care of removing things that wash ashore but this was too much. "This thing is big," Jeff Walters of the Department of Land and Natural Resources' division of aquatic resources, said yesterday morning as the state weighed its options. "We need something big. We either have to have a crane to lift it up whole or something to cut it up into smaller pieces.“ At one point, he thought a backhoe could be used to chop it up, but anyone getting close to the carcass would have to wear protective clothing. "It is putrid," he said. So yesterday afternoon they hired a crane from Bob's Equipment. By 4 p.m. the biggest chunk had been removed and taken across the highway to Kualoa Ranch. DLNR spokesman Mike Markrich said four large chunks still remaining on on the beach will be taken away today by backhoe. The dead whale was first spotted Wednesday on a reef about 100 yards offshore, and signs were posted warning beachgoers to stay out of the water because of the possibility of sharks. The signs remained up today, but Walters said the carcass is so decomposed that even sharks probably don't want it.

How do marine turtles regulate salt in their body?
Inquiry What is a natal beach? What advantage is there in turtle hatchlings leaving in a group rather than individually? Are the consequences for harassing a turtle adequate? How does the fibropapilloma virus effect green sea turtles? What is a TED? What is the difference between an odontocete and mysticete? How do marine turtles regulate salt in their body?

Vertebrate Biology Lecture 26.

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Vertebrate Biology Lecture 26.

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