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
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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