Phylum Chordata Subphyla Invertebrata Vertebrata from sea otters

Phylum Chordata Subphyla Invertebrata & Vertebrata from sea otters to sea squirts

Chordates 4 pharyngeal slits - a series of openings that connect the inside of the throat to the outside of the "neck". These often, but not always, become the gills. 4 dorsal nerve cord - a bundle of nerve fibers which runs down the "back". It connects the brain with the lateral muscles and other organs. 4 notochord - cartilaginous rod running underneath, and supporting, the nerve cord. 4 post-anal tail - an extension of the body past the anal opening.

Invertebrate Chordates 4 Urochordata: marine sessile animals that feed by filtering food particles from seawater taken in through their gill slits. 4 Cephalochordata: a dorsal nerve cord, notochord and gill slits

Subphylum Urochordata: 4 Tunicates & sea squirts 4 sessile, marine filter feeders w/ tadpole like larvae (comp, embryology) Anatomy of a Tunicate

Subphylum Cephalochordata 4 Lacelets, Amphioxus 4 notocord persists through adulthood

Subphylum Vertebrata 4 vertebral column. hollow bones protecting nerve cord replace notocord 4 distinct head with skull and brain 4 3 classes of fishes: – Agnatha, chondrichthyes, osteichthyes 4 4 classes of tetrapods 4 The Kingdom of Animalia, Vertebrates: Common Types and Their Unique Characteristics

Fishes (Ichthyes) 4 Aquatic or marine 4 respire with gills 4 2 chambered single looped circulatory system 4 plural can be fish or fishes depending on species Fish Adaptations

Agnatha- “jawless fishes” 4 Lampreys and hagfishes 4 Lack jaws and have permanently open rasping mouths 4 scavengers & predators of osteichythyes 4 unpaired fins 4 cartilaginous skeleton some

Class Agnatha 4 "w/o jaws" lampreys and hagfishes lampreys=anti-coagulant 4 eel like, scaleless slimy skin, hagfish eats inside out 4 lack paired fins 4 mostly cartilage skeleton 4 no well developed vertebral column 4 notochord=major support structure 4 jaws form from gill arches

Chondricthyes- "cartilaginous fish. " 4 Sharks, skates, rays, Members of the Chondrichthyes all lack true bone and have a skeleton made of cartilage (the flexible material you can feel in your nose and ears). Only their teeth, and sometimes their vertebrae, are calcified so they rarely fossilize 4 Must swim to pass water through spiracles, no swim bladder 4 Don’t seem to get cancer

Class Chondrichthyes 4 Cartilaginous fishes, which 4 4 have flexible endoskeletons made of cartilage rather than bone. Sharks have streamlined bodies, but it sinks if it stops swimming Shark teeth evolved from the jagged scales that cover the abrasive skin. A spiral valve within the shark intestine increases surface area. The lateral line system runs along the length of each flank o the shark; sensitive to changes in the surrounding water pressure.

Osteichthyes- “bony fishes” 4 Skeleton more or less bony, vertebrae numerous; 4 Skin with mucous glands and embedded dermal scales; 4 Fins median and paired with rays of cartilage or bone. Mouth with many teeth (some toothless); jaws present. Ray-finned fishes 4 Respiration by gills supported by bony gill arches and covered by a common operculum. 4 Swim bladder often present. 4 Most species are oviparous and fertilization is external. 4 Catfish, Air Breathing Catfish Lobe-finned fishes

Class Osteichthyes 4 Bony fishes: include ray-finned, lobe 4 4 -finned, and lunged. Operculum- draws water into the mouth through the pharynx and out between the gills; allows bony fish to breath while stationary. Swim bladder- an air sac that helps control the buoyancy of the fish Most species are oviparous, which means they lay eggs that hatch outside of the mother’s body, although some have internal fertilization. Lateral Line,

More Bony Fishes 4 Ray-finned fishes- fins are supported by long flexible rays, modified for maneuvering, defense; live in fresh water and salt water. 4 Lobe-finned fishes- have muscular pectoral and pelvic fins supported by extensions of the bony skeleton. 4 Lungfishes- use their gills as the main organs for gas exchange, but when ponds shrink during the dry season, lungfish can burrow in the mud and aestivate (wait in a state of torpor).

Amphibian “two lives” 4 tetrapods 4 respire through skin, lungs 4 4 4 4 and gills metamorphosis Orders Gymnophiona (apopoda), Anura, Urodela 3 chambered heart external fertilization & development ectothermic environmental sentinels Adaptable Amphibians

Orders of Amphibians 4 Order Anura- “tail-less one. ” Includes frogs. Exhibit color patterns that camouflage and the skin glands secrete distasteful or poisonous mucus. 4 Order Urodela- “tailed ones. ” Salamanders. Retain their tails as adults. 4 Order Apoda- “legless ones. ” Caecilians which burrow in the soil. 4 All amphibians go through a complete metamorphosis.

The link from water to land 4 As animals evolved, there was a 4 4 4 movement from an all water habitat to an on land habitat. However, there had to be a link between these two. Amphibians are attached both to the water and to the land. They have moist skin through which gas respires. They have lungs as adults and gills as larva. Their bodies adapted to prevention of predation and acquisition of food.

Reptilia 4 Dry scaly skin of keratin 4 ectothermic 4 3 chambered heart 4 amniotic egg 4 breathe through lungs exclusively 4 Orders Squamata, Chelonia, Crocodilia, Tuatara Reptile Adaptations

How would you classify this organism? Reptile Video Quiz

Aves 4 Endothermic 4 4 chambered heart 4 air sacs 4 feathers of keratin protected by oil 4 crop & gizzard 4 hollow bones 4 scales 4 amniotic egg

Class Aves 4 Common characteristics: 4 Light skeleton made of hollow bones; 4 4 some organs are also absent to allow for a lighter body. The beak is made of keratin, and has proven to be very adaptable to different diets during avian evolution. Birds are endothermic; they use their own metabolic heat to maintain a warm, constant body temperature. Feathers aid in flying and insulation. Exhibit highly proficient lungs with the adaptation of air sacs, which function to use 90% of the oxygen in air compared to the 10% that we use.

Origin of Birds 4 Theropods- a group of relatively small, bipedal carnivorous dinosaurs that most likely gave rise to birds. 4 Archaeopteryx- ancient creature possessing characteristics of both birds and reptiles. Bird Adaptations

Modern Birds 4 There are 28 orders of birds. 4 Ratites, “flat-bottomed, ” - flightless birds including the ostrich, kiwi, and emu. 4 Flying birds have a sternal keel supporting their large breast muscles, which provide flight power. 4 Many birds have extensive courtship and mating behavior.

Mammalia 4 Mammary glands for feeding young 4 hair/fur from ketarin 4 differentiated teeth 4 endothermic with 4 chambered heart 4 3 Groups: monotremes, marsupials, placentals

Monotremes 4 The platypuses and the echidnas, or spiny anteaters, are the only living mammals that lay eggs. 4 They have hair and produce milk, although not through nipples. 4 After hatching, the baby sucks the milk from the fur of the mother who has specialized glands that secret the milk. 4 The egg they lay is reptilian in structure and development.

Marsupials 4 Marsupials- born very early in its development and completes its embryonic development while nursing in a maternal pouch. 4 This pouch is called the marsupium. 4 The fetus remains in the pouch until it is large enough to emerge, but stays with the mother to nurse. 4 Include animals such as opossums, kangaroos, badicoots, and koalas.

Placental mammals 4 Also called eutherian mammals, which complete their embryonic development within the uterus, joined to the mother by the placenta. 4 Order Carnivora- includes cats, dogs, raccoons, skunks, and the pinnipeds, or seals, sea lions, and walruses. 4 Order Rodentia- includes rodents and primates. This is the largest order of mammals.

primates 4 Characteristics: 4 Most have hands and feet adapted for grasping, large brains and short jaws. 4 They also have flat nails on their digits rather than the narrow claws of other mammals. 4 Primates have well-developed parental care and complex social behavior. 4 Opposable thumb- relatively mobile and separate from the fingers in all primates. It is used for gripping branches and precise manipulation.

Test your knowledge 1. What are the four characteristics of vertebrates? __________, and _________. 2. What is the lateral line system? ____________________________. 3. What is the function of the swim bladder found in Osteichthyes? ________________. True or False: 4. To aestivate is to wait in a state of torpor. ______ 5. Amphibians are tied to the water only through their need to reproduce. _____ 6. Birds are ectothermic. _____ 7. Monotreams do not have nipples. ____ 4 In groups of 3 or 4, discuss the following questions: 1. What enabled amphibians to inhabit the land? Keep in mind gas exchange, reproduction, support, and locomotion. 2. Do you think that Archaeopteryx is a link between dinosaurs and birds? Give at least 2 reasons why or why not. 3. Explain the differentiation of teeth found in mammals. Keep in mind carnivore, herbivore, and omnivore life styles.

References 4 Explorations in Shark Diversity: 4 PBS Shape of Life: 4 Tree of Life Web 4 Chordate Notes 4 Smithsonian Marine Station Chordates