Chordates An Introduction Kingdom Animalia All inverts verts

Chordates An Introduction

Kingdom Animalia- All inverts & verts 1. Phylum Chordata: All have nerve cords. subphyla : A- Urochordata (tunicates aka sea squirts). Only larvae have notochord B-Cephalochordata (lancelets aka Amphioxus). Retain notochord throughout adulthood, but “musclelike” for burrowing C-Vertebrata- Notochord becomes backbone. 7 Classes 3

Section 33 -1 Concept Map Chordates have the following key features Notochord which is A flexible supporting structure Dorsal hollow nerve cord Postanal tail Pharyngeal gill slits/ pouches

Chordates 4

Phylum Chordata 5

Phylum Chordata • Notochord • Gill slits or pharyngeal pouches • Dorsal hollow nerve cord • Postanal tail • Segmented muscles • Deuterostome 6

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Evolutionary Adaptations of Chordates • From filter feeding ancestors to active predators – – – Mobility Oxygen capture Digestion Circulation Nervous system 11

Skeletal Changes • Skeleton becomes stronger to work with bigger muscles • Allows more rapid movement 12

Oxygen Capture • Gill slit and muscular pharynx will move more water over gills – More oxygen is extracted from water 13

Circulation • Stronger heart to circulate blood faster 14

Digestion • Digest more food – Muscularized gut – Digestive glands • Liver • Pancreas 15

Nervous System • More complex for better – Motor control of body to capture food – Sensory detection of the animals environment – Integration centers (brain) 16

Brain With Three Parts Hindbrain Midbrain Forebrain 17

Section 33 -1 Nonvertebrate chordates Jawless fishes Cartilaginous fishes Bony fishes Amphibians Reptiles Birds Mammals Figure 33– 2 A Cladogram of Chordates

Checkpoint 1. What are the 4 traits that chordates display at some point in their lives? 2. Give 5 examples of Adaptations that allow animals to seek, pursue, and capture prey. 3. Are all vertebrates also chordates? 4. Are all chordates also vertebrates?

Chordate Cladogram Birds Amphibians Fishes Nonvertebrate chordates Invertebrate ancestor Reptiles Mammals

Figure 33– 4 Diversity of Chordates Section 33 -1 Nonvertebrate chordates (4%) Mammals (8%) Birds (18%) Reptiles (14%) Amphibians (9%) Fishes (47%)

Chordate Subphyla Chordata Phylum. Subphylum. Urochordata Subphylum. Cephalochordata Subphylum. Vertebrata 22

Sea Squirts 23

Subphylum Urochordata • Sea squirts (aka tunicate) • Gill slits (pharyngeal slits) • Notochord – Only in larva • Adult has tunic- made of cellulose, sessile • http: //www. arkive. org/starascidian/botryllus-schlosseri/ • http: //finstofeet. wordpress. c om/2010/03/14/1 -2 -beholdthe-tunicates/ 24

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https: //www. youtube. com/wat ch? v=n 8 ARUKWPJAE

Subphylum Cephalochordata • Amphioxus (lancelets) • Notochord length of body • Dorsal hollow nerve cord • Gill slits • Segmented muscles • Maintain all chordate characteristics as adult 29

Amphioxus https: //www. youtube. com/wat ch? v=GPn. PXsancl. Y 30

Amphioxus 31

Subphylum Vertebrata: All Vertebrates have: • • • Endoskeleton- backbone Closed circulatory system Bilateral symmetry True coelom Sexual reproduction- internal or external Vertebrate Groups- Fish, Amphibians, Reptiles, Birds, and Mammals

Homeostasis • Endothermic (warm-blooded)- internal temp. regulation that must be maintained Ex. Birds & Mammals • Ectothermic (cold-blooded)- external temp. regulation/ regulated by environment Ex. Nonvertebrate chordates, Fish, Amphibians, Reptiles

Temperature Control in Chordates Body Temperature (°C) Section 33 -2 Environmental Temperature (°C) 98. 6 F- avg human temp

How vertebrates maintain their temperature Animal Group Endo/ectotherm Behavior/structure Fish Ectotherm Swim bladder: Cold/move up Hot/move down Amphibian Ectotherm Cool/go in sun Hot/go to water Reptile Ectotherm Cool/bask Hot/go to water Birds Endotherm Cool/fluff feather Hot/raise wings Mammals Endotherm Sweat, pant, shiver

Kingdom Animalia Phylum Chordata Subphylum Vertebrata Class Agnatha “Jawless” Fish (most primitive): Traits: -Sucker like mouth(no jaws) -No fins or paired appendages -Cartilage skeleton w/ notochord Ex: lamprey & hagfish

Kingdom Animalia Phylum Chordata Subphylum Vertebrata Class Chondrichthyes-Cartilage Fish

Class: Chondricthyes Traits: • Cartilage skeleton; 2 chambered heart • Lateral line system –detect vibrations (movement & sense) • Electroreception- ampullae of Lorenzini • Paired appendages- pectoral and pelvic girdles • Poor eyesight, great olfactory • Carnivorous or scavenger, no swim bladder • Ex: sharks, skates, rays

http: //missbakersbiologyclass. com/blog/2009/ 04/06/dogfish-shark-dissection-includesvideo/

http: //www. youtube. com/watch? v=NTM 0 K 6 t. EIo A dead shark live babies

Fish Scales

Tails Sharks and rays lungfish Bony fish

Fish Tail Cladogram

Kingdom Animalia Phylum Chordata Class Osteichthyes. Bony Fish Traits: Bony skeleton; 2 chambered heart Lateral line system/movement & sense Swim bladder-control depth (buoyancy) Have operculum over gills Good smell (olfactory) and eyesight Ex: perch, bass, flounder

http: //www. youtube. com/watch? v=p. NZQEm. Gp 11 k