Invertebrate Zoology

What’s in a name?

• Invertebrates lack a backbone

• Why is this so important?

• Well…

– we make up the scheme

– we have a backbone

– ergo, it’s important

What if insects

ruled the world?

• Insects have six legs

• they would make up the scheme

• ergo the animals would be divided up

into:

– hexopods

– non-hexopods

Let’s be frank…• There are an estimated 3-15 million animal

species

• Let’s lowball and say there are 3 million…

• There are 47,000 known species of vertebrates

• This is the picture that emerges:

Invertebrates Vertebrates

The bauplan…

• Bauplan = basic body plan

• Each phylum has a somewhat unique one

• It is the common morphological theme

that unites members of a group

• Its based on shared characteristics not

the shared lack of a characteristic

Our Challenge

• Introduce the bauplan for major

animal phyla

• Recognize how it has been modified

in extant groups

• Relate it to the environment in which

they live

• Explore evolutionary relationships

between invertebrate phyla

2 Major Branches (Groups)

• Protostomes

– Proto = 1st

– Stoma = mouth

• Deuterostomes

– Deutero = other

Major Characteristics

• Types of tissues in body plan

– Ectoderm, mesoderm, endoderm

• Ecto = outer, meso = middle, endo = inner

– Ecto + endo = diploblastic

– Ecto + endo + meso = triploblastic

Major Characteristics

• Patterns of cell cleavage in early embryology

– Spiral vs radial cleavage

• Coelomate vs acoelomate

– Coelom = fluid filled cavity lined with mesoderm

• Pattern of coelom formation

– Schizocoely vs enterocoely

Major Characteristics

• Coelomate vs acoelomate

– Coelom = fluid filled cavity lined with mesoderm

• Pattern of coelom formation

– Schizocoely vs enterocoely

• Class Homepage:

http://courses.pbsci.ucsc.edu/eeb/bioe122/

• Text: Invertebrate Zoology, Rupert, Fox &

Barnes, 7th edition

• Laboratory Manual: online & free!

Other details…

• Dissection kits: issued in lab, part of your course fee

• Colored pencils for lecture: red, green, blue, orange, yellow, and at least one other (I use purple)

• You must be enrolled concurrently in one of the four laboratories Tu (pm), W (pm), W (eve), Thu (pm)

– First labs meet this week - check in and orientation

– Labs are down at the Marine Lab in the Seymour Center

Other details…

• Grades

• Two in-class written exams

– Midterm & final

• Approx. 5 take home written assignments

– About every other week

– Collectively worth one exam

• Lab grading discussed in lab

• Lecture grade

– Exams & take home = 75%

– Lab = 25%

Some Friendly Advice…

• Invertebrate Zoology is a term rich science

• I will provide a list of all terms that I expect you to know 1 week prior to each exam

• Don’t make the mistake of thinking that if you know the terms, you know the material

• Let’s use the metaphor of the piano

• Piano keys = terms

• I expect you to be able to play a melody

• I won’t expect Chopin but…

• Chopsticks isn’t going to cut it