Phylum Chordata NOTES April 26, 2012

<strong>Phylum</strong> <strong>Chordata</strong> <strong>NOTES</strong><br />

The Chordates--the end of our journey<br />

Domain: Eukaryota<br />

Kingdom: Animalia<br />

<strong>Phylum</strong>: <strong>Chordata</strong><br />

Marine Examples:

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<strong>Phylum</strong> <strong>Chordata</strong> <strong>NOTES</strong><br />

Also a<br />

Chordate?!?!?!

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<strong>Phylum</strong> <strong>Chordata</strong> <strong>NOTES</strong><br />

**Three distinct characteristics define this phylum***<br />

Chordates have these 3 characteristics at some point during their life.<br />

1. Notochord<br />

2. Gill slits<br />

3. Dorsal, hollow Nerve Cord<br />

*Sometimes during the larval or embryo stage can have a post anal<br />

tail.<br />

*All have a ventral heart

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<strong>Phylum</strong> <strong>Chordata</strong> <strong>NOTES</strong><br />

Links between invertebrate echinoderms and chordates:<br />

<strong>Phylum</strong> Hemichordate- Acorn Worm<br />

<strong>Phylum</strong><br />

<strong>Chordata</strong><br />

*Share several features related to the development of the embryos.<br />

*The <strong>Phylum</strong> Hemichordata (which we do not discuss) appears to link<br />

the echinoderm and chordate phyla.<br />

*Hemichordate larvae are similar to some echinoderms but share<br />

some characteristics with chordates (dorsal, sometimes hollow nerve<br />

cord, gill slits).

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<strong>Phylum</strong> <strong>Chordata</strong> <strong>NOTES</strong><br />

Invertebrate Chordates:<br />

*Not all chordates possess a backbone. A backbone is not a major characteristic of this<br />

phylum.<br />

"All vertebrates are chordates, but not all chordates are vertebrates"<br />

*There are 2 subphyla of invertebrate chordates:<br />

Sea squirt.mp4<br />

Subphylum Urochordate Ex. tunicates, sea squirts<br />

--1,400 species<br />

--Most sessile as adults<br />

(docks, boats, etc.)<br />

--How do they feed?<br />

--Planktonic larval stage (look like a tadpole)<br />

+larval stage does not feed. Locates surface to settle.<br />

+larva undergoes a “spectacular” metamorphosis.

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<strong>Phylum</strong> <strong>Chordata</strong> <strong>NOTES</strong><br />

Subphylum Cephalochordata<br />

Ex. Lancelets (Amphioxus)<br />

--29 species<br />

--Looks fish-like but does not<br />

have a backbone. (7 cm in length)<br />

--Benthic. Found in soft bottoms.<br />

--How do they feed?

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<strong>Phylum</strong> <strong>Chordata</strong> <strong>NOTES</strong><br />

<strong>Phylum</strong> <strong>Chordata</strong><br />

Subphylum Vertebrata<br />

Vertebrate Characteristics:<br />

*approx. 52,000 species<br />

*Posses a vertebrae.<br />

Define:<br />

--What do the vertebrae enclose and protect?<br />

*Symmetry?<br />

*Type of skeleton?<br />

--What other phylum had the same type of skeleton?<br />

*Closed Circulatory System

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<strong>Phylum</strong> <strong>Chordata</strong> <strong>NOTES</strong><br />

*Nervous system characteristics:<br />

* Both external fertilization and internal fertilization are seen in this<br />

<strong>Phylum</strong>.<br />

*Both external development and internal development are seen in this<br />

<strong>Phylum</strong>.

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<strong>Phylum</strong> <strong>Chordata</strong> <strong>NOTES</strong><br />

**The Subphylum Vertebrata has 7 classes<br />

CLASS NAME<br />

1. Class Agnatha<br />

2. Class Chondricthyes

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<strong>Phylum</strong> <strong>Chordata</strong> <strong>NOTES</strong><br />

3. Class Osteicthyes<br />

--What is the swim bladder?

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<strong>Phylum</strong> <strong>Chordata</strong> <strong>NOTES</strong><br />

4. Class Amphibia<br />

5. Class Reptilia<br />

Define Ectotherm (poikilotherm).<br />

AKA: cold-blooded

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<strong>Phylum</strong> <strong>Chordata</strong> <strong>NOTES</strong><br />

6. Class Aves<br />

Feathers<br />

Define Endotherm (homeotherm)?<br />

AKA: warm-blooded

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<strong>Phylum</strong> <strong>Chordata</strong> <strong>NOTES</strong><br />

7. Class Mammalia