Invertebrates Flashcards
which phylum represents the basal Metazoan?
Porifera
Phylum Porifera
- “to have pores” - sponges
- least complex animals (MC, differentiated cells, and no symmetry, tissues or organs)
Simple Sponge Morphology
osculum: open end
spongocoel: central cavity
NOT a digestive cavity - digestion is intracellular
what is the SDT for Porifera?
choanocytes
- “Collar cells” - feeding cells of sponges
- Very similar to choanoflagellates
- Flagellated
- Collar of microvilli
- Line spongocoel
- Ingest bacteria, food particles
what phylum represents the basal Eumetazoa?
Phylum Cnidaria
what are the Eumetazoan SDTs?
- true tissues
- radial symmetry
- diploblastic
what are the SDTs for Cnidaria?
Cnidocytes
- Specialized stinging cells
- Thin (2 layers), gastrovascular activity
- Mostly marine
what is so special about protostomes?
- diverse, paraphyletic group
- must have ancestral (protostome) development traits
- some have derived (deuterostome) development
is Deuterostome a mono-, para-, or polyphyletic group? why?
Mono because all have derived development traits
what are ancestral traits for Lophotrochozoan?
from bilateria ancestor
- bilateral symmetry
- triploblastic
- protostome development (some have deutero. pattern)
what is the SDT for Platyhelminthes?
Acoelomates
Describe Platyhelminthes
- Dorsoventrally flattened
- Can be free-living or parasitic
describe Rotifera
- freshwater/marine, damp soil
- Very small
what are the SDTs for Rotifera?
- Corona: crown of cilia at anterior end
- Pseudocoelomate
what are the 3 main body parts/SDTs for Mollusca
- mantle: thin sheet of tissues covering visceral mass (often secretes CaCO3)
- visceral mass: main body mass, contains viscera (internal organs)
- foot: structure for locomotion
