Kingdom Animalia Phylum Chordata. The vertebrates and their relatives

Transcription

1 Kingdom Animalia Phylum Chordata The vertebrates and their relatives

2 Figure 23.02

3 Phylum Chordata 5 Characteristics of a chordate 1. A dorsal hollow nerve cord (spinal cord in vertebrates) 2. A notochord (most vertebrates only have a notochord during development becomes the backbone in vertebrates) 3. Pharyngeal Pouches (develop into gills in fish and amphibians) 4. Muscular Tail (disappears in humans) 5. Thyroid Gland-secretes mucos that traps food in pharyngeal cavity

4 Five Chordate Hallmarks Dorsal tubular nerve cord

5 Five Chordate Hallmarks Notochord flexible rodlike structure; extending length of body

6 Five Chordate Hallmarks Pharyngeal pouches and gill slits

7 Five Chordate Hallmarks Postanal tail tail extends beyond anus

8 Five Chordate Hallmarks Endostyle or thyroid gland secretes mucous that traps food particles in pharyngeal cavity

9 Sixth Chordate Feature Ventral Heart heart located ventrally

10 Major Characteristics of Chordates

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

12 Subphylum Urochordata Tunicates (also known as sea squirts ) Look similar to other chordates during development, but completely different as adults

13 Subphylum Cephalochordata Lancelets: live in the ocean with their body buried in sand Have a definite mouth and no jaws Long pharynx with up to 100 gill slits Breathe through their body surface Have a simple digestive system, heart, and closed circulation Notochord and nerve chord run entire length of body

14 Amphioxus

15 Subphylum Vertebrata 99% of chordates are vertebrates Fish 24,000 species Amphibian 4,000 species Reptiles 6,000 species Birds 10,000 species Mammals 5,200 species

16 Phylum Chordata: The Vertebrates Subphylum Vertebrata Nine extant classes First 3 commonly called fishes Remaining 4 called tetrapods (4 feet) All possess some form of segmented vertebra

17 Vertebrate Higher Classification Superclass Agnatha - without jaws Class Myxini hagfishes Class Cephalaspidomorphi lampreys Superclass Gnathostomata with jaws Class Chondrichthyes sharks, rays, chimaeras Class Actinopterygii ray-finned fishes Class Sarcopterygii lobe-fin fishes Class Amphibia frogs, salamanders Class Reptilia snakes, lizards, crocodiles Class Aves - birds Class Mammalia - mammals

18 Fishes Aquatic vertebrates characterized by: Fins (Movement) Scales (Protection) Gills (Breathing) There are fish with exceptions! Can you name any?

19 Fish Evolution Fish were the first vertebrate to evolve Evolved about 540 mya Were jawless and covered in armored plates Devonian Period = Age of the Fishes Fish developed both jaws and fins at this time

20 Possible evolution of 1 st fish 1 st fish lancelet Proto-vertebrate Tunicate larvae Adult tunicate

21 Early Chordate ancestor may have given rise to 1 st vertebrate Pikaia Burgess Shale Fauna Cambrian mya

22 Groups of Extant Fishes Class Cephalospidomorphi lamprey Class Myxini hagfishes Class Chondrichthyes cartilaginous fishes Class Osteichthyes bony fishes

23 Classroom News Hope you are studying or plan on studying this weekend to best prepare for your exam (2 nd test of 3 rd nine week) Lots of great material to cover today including introduction to major systems Frog Anatomy Quiz Tuesday Potential for pushing test back till March 6th

24 Agnatha (jawless fishes) Lack: paired fins, scales, & well developed vertebrae Hagfish (slime eels) Mucus for protection Feed on decaying flesh Lampreys Parasitic Anadromous Marine adults, breed in freshwater Vampire fish

25 Lamprey and Hagfishes Are jawless fishes Have mouths of soft tissue and no true teeth Have no bones Are the only vertebrates that do not have vertebral columns as adults

26 Lamprey Are filter feeders as larvae and parasites that suck blood and tissues of fish as adults River Monsters

27 Hagfishes Feed on dead and dying fish using a toothed tongue to scrape a hole in the fishes side Secrete large amounts of slime Have 6 hearts and an open circulatory system

28 Class Chondrichthyes Include sharks & rays Very successful class Called cartilaginous fishes because skeleton is cartilage not bone Approx. 750 species Have paired appendages Many have acute senses Sharks have a lateral-line system Allows shark to detect water pressure changes

29 Cartilaginous Fishes Includes sharks, rays, skates, sawfishes, and chimaeras Chondros = Greek word for cartilage A typical shark has 3000 teeth arranged in 6 to 20 rows Not all are carnivores, the largest sharks are filter feeders Some have flat teeth for crushing mollusks and crustaceans

30 Class Osteichthes

31 Class Osteichthes Called Bony fish Most diverse of all fish Have skeleton made of bone Have paired fins Allowed evolution of 4 limbed amphibians (tetrapods) Possess scales for protection Have bony flap called operculum Allows water to be drawn over gills by fins Have Swim bladder for buoyancy

32 Bony Fishes Skeletons are made of calcified bone Includes fish we are most familiar with: Sunfish, Trout, Crappie, catfish, Larghmouth Bass, etc.

33 Fish Ecology Some fish can live in both salt water and fresh water Anadromous Fishes spend most of their life in the ocean but move to fresh water to breed Catadramous Fishes spend most of their life in fresh water but move to the ocean to breed

34 Body Systems of Fishes Fish feed in a variety of ways including parasites, carnivores, herbivores, etc. Most fish breathe using gills Gills are feathery filaments containing a network of capillaries to increase surface area for CO 2 and O 2 exchange Fish have two chambered heart and closed circulation

35 Body Systems of Fishes Fish digestive systems are similar to that of humans Excretory system is slightly different Ammonia is excreted by diffusion of water through gills and by use of kidneys

36 Body Systems of Fishes **How does the action of peeing differ in a marine environment vs fresh water?

37 I got to go pee!!!

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40 Osmoconformers vs. Osmoregulators What is the difference?

41 Osmotic Challenges Osmoregulation- regulates solute concentrations and balances the gain and loss of water Osmoconformers, consisting only of some marine animals, are isoosmotic with their surroundings and do not regulate their osmolarity Osmoregulators expend energy to control water uptake and loss in a hyperosmotic or hypoosmotic environment

42 Hagfishes Osmoconformers Only vertebrate that is isotonic to seawater - much like marine invertebrates

43 Osmoregulators Aquatic vertebrates - gills are chief organs of excretion/osmoregulation Kidneys first evolved as osmoregulatory organs in fishes to remove water (freshwater) or conserve water (marine)

44 Do I drink water? Describe my pee. Do I drink water? Describe my pee.

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46 Figure 44.3 (a) Osmoregulation in a marine fish (b) Osmoregulation in a freshwater fish Gain of water and salt ions from food Excretion of salt ions from gills Osmotic water loss through gills and other parts of body surface Gain of water and some ions in food Uptake of salt ions by gills Osmotic water gain through gills and other parts of body surface Gain of water and salt ions from drinking seawater Excretion of salt ions and small amounts of water in scanty urine from kidneys Key Water Salt Excretion of salt ions and large amounts of water in dilute urine from kidneys

47 Body Systems of Fishes **How does the action of peeing differ in a marine environment vs fresh water? Salt water fish lose water and thus conserve bodily fluids by having concentrated urine Fresh water fish gain water and to have dilute urine Fish that move from fresh to salt water alter their kidney function to adapt to tonicity!

48 Fish exhibit cephalization (brain) Many fish have Chemoreceptors for an extraordinary sense of taste and smell Lateral Line System allows fish to sense movement and vibration Fish Senses

49 Fish Senses Swim Bladder adjust buoyancy How does pulling a fish from 40 feet of water affect the size of its swim bladder?

50 Class Amphibia Amphibians gave rise to all other land vertebrates Amphibian means double life As larvae they are typically aquatic filter feeders or herbivores breathing through gills As adults most species are terrestrial carnivores that breathe through their moist skin and have lungs

51 Adaptations to Life on Land As the amphibians developed in the late Devonian Period 360 mya they needed to adapt to terrestrial life Keep from drying out Breathe using lungs, not gills Bones in limbs allow movement Ribs to support and protect internal organs Amphibians dominated the Carboniferous Period 345 to 285 mya

52 Amphibian Body Systems Amphibians have a well developed digestive system similar to that of humans As most amphibians develop lungs as adults, some are lung-less and only breathe through their skin They have closed circulation and a 3 chambered heart with a double loop system similar to that of a human Ammonia is disposed of in urine through the use of kidneys

53 Amphibian Reproduction Most amphibians lay their eggs in water; fertilization is external Some salamanders fertilize internally

54 Amphibian Reproduction In most cases of external fertilization, the male will attach itself to the female. Eggs and sperm are released simultaneously and encapsulated in a jelly that attaches to aquatic plants. The jelly nourishes the developing embryos Tadpoles hatch and metamorphose into adults

55 Amphibian Reproduction Most amphibians abandon their eggs once they lay them. Some care for both eggs and young Some incubate their eggs in unusual places: in their mouth, on their back, or in their stomach

56 Amphibian Senses Amphibians have a well developed brain and spinal cord similar to that of a fish Eye s are protected by a nictitating membrane A tympanic membrane, or eardrum, is located on either side of the head Many have a lateral line system similar to that of a fish

57 Groups of Amphibians Order Urodela: Salamanders and Newts Order Anura: Frogs and Toads Order Apoda: Caecilians

58 Salamanders and Newts Have long bodies and tails Both adults and larvae are carnivores Most adults are terrestrial and live in damp forests Some salamanders, such as mud puppies, keep their gills and live in water all their lives

59 Frogs and Toads Have the ability to jump Frogs have longer legs and can jump farther than toads Frogs are closely tied to water; toads are more terrestrial

60 Caecilians Least known of the amphibians Are legless and burrow in moist soil or sediment Feed on small invertebrates such as termites Some have scales

61 Amphibian Ecology Most are a great meal for birds and reptiles Some have toxins to poison predators Some have bright colors to warn of their toxins Some mimic the bright colors of others and are harmless

62 Amphibian Ecology Amphibian populations are declining worldwide due to several factors: Global Warming Decreasing Habitat Depletion of the Ozone Water Pollution Introduced Aquatic Predators Fungal Infections Increasing human population!

63 Amphibian Anatomy We can use amphibian anatomy to model our own complex anatomical systems Many of the systems we have already discussed, but we now cover them a bit more in depth

64 Respiratory System Exchanging of gases via two well developed lungs Major Structures: 1. Mouth 2. Trachea 3. Lungs (left & right)

65 Cardiovascular System Process of exchanging oxygenated blood with deoxygenated blood via a heart a series of arteries and veins

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67 Cardiovascular System Process of exchanging oxygenated blood with deoxygenated blood via a heart a series of arteries and veins

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76 Class Reptilia Land vertebrates with a well developed skull, a backbone and tail, and four limbs Exemptions: snakes have no legs, and turtles have a shell formed of fused vertebrae? Can a turtle lose its shell?

77 Reptile Evolution The oldest reptile fossils date back to the early Carboniferous Period some 350 million years ago Dinosaurs of the Triassic and Jurassic Period ruled the earth until 65 million years ago

78 Reptile Body Systems Reptiles are ectotherms rely on interactions with the environment to control their body temperature Reptiles have well developed lungs, four chambered hearts, and a well developed brain and spinal cord Reptiles legs are rotated farther under their body than amphibians allowing them to carry weight and walk on land more efficiently

79 Reptile Reproduction Internal Fertilization males have a penis to place sperm in the female s cloaca Most are oviparous Turtles leave their nests unattended while alligators protect their nest Some snakes are ovoviviparous

80 Reptilian Eggs Reptiles have amniotic eggs named after one of the four membranes around the developing embryo Amnion: produces watery environment around embryo Yolk Sac: contains nutrient rich yolk that feeds embryo Chorion: allows gas exchange Allantois: stores waste

81 Groups of Reptiles Order Squamata: lizards and snakes Order Crocodilia: alligators, crocodiles, caimans, and gavials Order Chelonia: turtles, tortoises, terrapins Order Rhynchocephalia - tuataras

82 Lizards and Snakes Most lizards have legs, clawed toes, external ears, and movable eyelids Some lizards do not have legs and look more like a snake

83 Alligators, Crocodiles, and their Long broad snout and squat appearance Fierce carnivores Very protective of their nests Alligators and Caimans live only in fresh water and almost exclusively in North and South America Crocodiles live in both fresh and salt water and are native to Africa, India, and Southeast Asia Relatives

84 Turtles, Tortoises, and Terrapins Turtles live in or near water Tortoises are terrestrial Terrapins live in brackish water Carapace: Dorsal side of Shell Plastron: Ventral side of Shell

85 Tuataras Tuataras are the only living member of the Order Rhynchocephalia Beak headed reptiles that live on a few small islands off the coast of New Zealand Differ from lizards as they lack external ears and retain primitive scales They have a legendary third eye which is part of a complex organs on top of the brain the function is unknown

86 Ecology of Reptiles Many are in danger due to loss of habitat Humans also hunt them for food, pets, and their skins (for bags and boots) Many conservation efforts are underway, but more are needed worldwide

87 Class Aves Characteristics of most birds Maintain a constant internal body temperature Covered in feathers Have two legs for walking and perching Front limbs are wings Most are adapted for flight

88 Feathers Used for flight and warmth; several types Contour Feathers: provide the lifting force and balance needed for flight Down Feathers: trap air close to the body and keep the bird warm Powder Down: found on ducks and other birds that live on or in water; release a fine powder that repels water

89 Evolution of Birds Oldest known fossil is Archaeopteryx which lived during the Jurassic Period 150 mya. Had teeth in its beak, a jointed tail, and toes and claws on its wings Birds are very closely related to dinosaurs, but scientists disagree on whether birds evolved from dinosaurs or- birds and dinosaurs evolved from one common ancestor

90 Body Systems of Birds Endotherms: can generate their own body heat; warm-blooded Smaller birds must eat more in relation to its size due to Surface Area to Volume Ratio

91 Feeding habits of Birds They lack teeth and therefore do not chew Beaks are adapted to the types of food they eat Bird Digestion Crop: enlargement of the esophagus used to store food Gizzard: has muscular walls and small bits of gravel used to grind food

92 Birds have very efficient lungs that provide oxygen rich blood during both inhalation and exhalation Inhaled air enters posterior and anterior air sacs it then travels through the lungs and is exhaled Therefore the air flows into the air sacs and out of the lungs in one single direction, always providing oxygen rich air Respiration

93 Circulation and Excretion Two loop circulatory system, similar to that of humans Ammonia is removed by the kidneys, converted to high concentration uric acid and defecated (bird droppings); similar to reptiles

94 Senses of Birds The brains of birds are very well developed Birds can see color very well Birds can hear very well Smell or taste are not well developed

95 Bones and Muscles Most birds can fly. Others are adapted for swimming and running Bones are light, strong, and adapted for flight; many bones are fused to provide a study base for flight adaptations

96 Bird Reproduction Both male and female reproductive tracts open into the cloaca The sex organs, internal in both sexes, increase in size during mating season Birds rub their cloacas together during mating to transfer sperm

97 Eggs and Incubation Eggs are amniotic but unlike reptile eggs have a hard outer shell Eggs must be incubated by the parents since they are endotherms Young must be cared for after hatching

98 Groups of Birds There are nearly 30 different orders of birds 60% of all birds worldwide are perching birds Show many examples!

99 Ecology of Birds Birds are very ecologically important Hummingbirds are involved in pollination Some birds eat seeds without digesting them and therefore spread the seeds Many birds keep insect populations in check Many birds migrate by guidance of stars, Earth s landmarks, and Earth s magnetic field Birds are good indicators of environmental health; bird numbers dwindled with the use of DDT

100 Class Mammalia Characteristics of mammals Endotherms Have mammary glands and nurse young Have hair

101 Evolution of Mammals The earliest mammals evolved about the same time as the early dinosaurs but remained in the shadows until the giant reptiles disappeared First ancestors of mammals appeared during the Permian Period about 290 to 250 mya First true mammals appeared during the Jurassic Period 210 mya

102 Mammal Evolution When the continents split about 60 mya, three groups of mammals were isolated from one another.

103 Animals have hair to help insulate their bodies. They also have subcutaneous fat to keep them warm and many have sweat glands to cool them off. Smaller mammals have higher metabolism than larger ones in order to create enough body heat to keep warm. Mammals eat about 10 times as much food as a reptile in order to stay warm. Staying Warm

104 Comparison of Vertebrate Forelimbs When comparing the bones and bone structures of all vertebrates - birds, amphibians, reptiles, and mammals you can see many of the same bones with very similar functions Refer to Figure 32-7 in the text (Page 826)

105 Mammal Reproduction Internal Fertilization occurs in mammals Mammals are divided into three groups based on methods of development and birth Oviparous: egg-laying mammals are called monotremes Viviparous: includes both placental mammals and marsupials

106 Caring for Young All newborn mammals feed on their mother s milk Some newborns are helpless at birth and must be cared for Others are able to see and walk within minutes after birth

107 Monotremes are the egg laying mammals They share two notable characteristics with reptiles Both the reproductive and urinary systems open into a cloaca Monotreme means single opening Only three species of monotremes exist today: they are found in Australia and New Guinea Duckbill Platypus and two species of Spiny Anteaters Monotremes

108 Laying eggs and caring for young Monotremes lay eggs that are incubated outside the body They hatch into young animals in about 10 days The young are nourished by their mother s milk that they lick from pores on the mother's abdomen

109 Marsupials Marsupials give birth to live young that complete their development in an external pouch Examples include kangaroos, wombats, koalas, and Tasmanian devils A short time after internal fertilization a small embryo leaves the mother s body, crawls across the fur, and enters the marsupium (pouch) where it attaches to a nipple to nurse

110 Placental Mammals Placental Mammals are those that are most familiar to us. Placenta organ in placental mammals through which nutrients, oxygen, carbon dioxide, and wastes are exchanged between embryo and mother Gestation the time it takes from conception to birth in mammals (can vary from 2 weeks to 2 years depending on the mammal)

111 Orders of Mammals There are 12 orders of placental mammals They are classified based on several criteria including Feeding Teeth and Jaw Structure Foot Structure Brain Development