chordates an introduction

ChordatesAn Introduction

Kingdom Animalia- All inverts & verts

1. Phylum Chordata: All have nerve cords. 3 subphyla :

A- Urochordata (tunicates aka sea squirts). Only larvae have notochord

B-Cephalochordata (lancelets aka Amphioxus). Retain notochord throughout adulthood, but “muscle- like” for burrowing

C-Vertebrata- Notochord becomes backbone. 7 Classes

Section 33-1

have the followingkey features

which is

Concept MapChordates

A flexiblesupportingstructure

Notochord Dorsal hollownerve cord

Pharyngealgill slits/ pouches

Postanal tail

Section 30-1

Muscle segments

Tail Anus

Pharyngeal pouches

Mouth

Hollownerve cord

Notochord

The Generalized Structure of a Chordate:

We even start out this way in the womb!

4

Chordates

5

Phylum Chordata

6

Phylum Chordata• Notochord• Gill slits or

pharyngeal pouches

• Dorsal hollow nerve cord

• Postanal tail• Segmented

muscles• Deuterostome

7

8

9

10

11

Evolutionary Adaptations of Chordates

• From filter feeding ancestors to active predators– Mobility– Oxygen capture– Digestion– Circulation– Nervous system

12

Skeletal Changes• Skeleton becomes

stronger to work with bigger muscles

• Allows more rapid movement

13

Oxygen Capture• Gill slit and muscular

pharynx will move more water over gills– More oxygen is extracted

from water

14

Circulation• Stronger heart to

circulate blood faster

15

Digestion• Digest more food

– Muscularized gut – Digestive glands

• Liver• Pancreas

16

Nervous System• More complex for better

– Motor control of body to capture food

– Sensory detection of the animals environment

– Integration centers (brain)

17

Brain With Three Parts

ForebrainMidbrainHindbrain

Section 33-1

Nonvertebrate chordatesJawless fishesCartilaginous fishesBony fishesAmphibiansReptilesBirdsMammals

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?

MammalsBirds

ReptilesAmphibians

Fishes

Nonvertebratechordates

Invertebrate ancestor

Chordate Cladogram

Section 33-1

Fishes(47%)

Nonvertebrate chordates(4%)

Mammals(8%)

Birds(18%)

Reptiles(14%)

Amphibians(9%)

Figure 33–4 Diversity of Chordates

22

Chordate SubphylaPhylum. Chordata

Subphylum. UrochordataSubphylum. CephalochordataSubphylum. Vertebrata

23

Sea Squirts

24

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/star-a

scidian/botryllus-schlosseri/• http://finstofeet.wordpress.c

om/2010/03/14/1-2-behold-the-tunicates/

25

26

27

29

Subphylum Cephalochordata• Amphioxus (lancelets)• Notochord length of

body• Dorsal hollow nerve

cord• Gill slits• Segmented muscles• Maintain all chordate

characteristics as adult

30

Amphioxus

31

Amphioxus

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

Section 33-2

Environmental Temperature (°C)

Bod

y Te

mpe

ratu

re (°

C)

Temperature Control in Chordates

98.6 F- avg human temp

Animal Group Endo/ectotherm Behavior/structure

Fish Ectotherm Swim bladder:Cold/move upHot/move down

Amphibian Ectotherm Cool/go in sunHot/go to water

Reptile Ectotherm Cool/baskHot/go to water

Birds Endotherm Cool/fluff featherHot/raise wings

Mammals Endotherm Sweat, pant, shiver

How vertebrates maintain their temperature

Kingdom AnimaliaPhylum ChordataSubphylum VertebrataClass Agnatha “Jawless” Fish (most primitive): Traits:-Sucker like mouth(no jaws)-No fins or paired appendages-Cartilage skeleton w/ notochordEx: lamprey & hagfish

Kingdom AnimaliaPhylum Chordata

Subphylum VertebrataClass Chondrichthyes-Cartilage Fish

Class: ChondricthyesTraits:• 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-includes-video/

http://www.youtube.com/watch?v=NTM0K6tEIoA

Fish Scales

Tails

Sharks and rays

lungfish Bony fish

Fish Tail Cladogram

Kingdom AnimaliaPhylum ChordataClass Osteichthyes-Bony FishTraits:Bony skeleton; 2 chambered heartLateral line system/movement &

senseSwim bladder-control depth

(buoyancy)Have operculum over gillsGood smell (olfactory) and eyesightEx: perch, bass, flounder

http://www.youtube.com/watch?v=pNZQEmGp11k