Week 8 Flashcards
What are the feeding structures of Bryozoans and Brachiopoda called
Lophophore
Platyhelminthes (flatworms) features
Acoelomate
triploblastic
organ level of organization
protonephridia
incomplete gut (no respiratory/circulatory systems)
ventral nervous system
monoecious with internal fertilization
What phyla does Lophotrocozoans include
Annelida (segmented worms), Mollusca (mollusks), and Platyhelminthes (flatworms)
Features that unite Lophotrochozoans
Lophophores
Trocophore larvae
Features of Turbellaria (planarians - free living flatworms)
Benthic (live at bottom) or marine and freshwater environments
muscles systems extend circularly as well as longitudinally
predators
cilia on ventral surface for mobility
flattened top to bottom (dorsoventrally)
Nervous system of turbellarians
Have centralization/cephalization - almost have a brain
Net-like system of nerves that allow one side of the animal to communicate with the other, some have lateral cords that run the length of the animal and are connected by commissure branches
Have sensory and motor nerves
are turbellarians monoecious or dioecious
monoecious
copulation is an exchange of sperm
direct development from hatching
What are teguments and why do trematodes have them
they are the outer epithelial layer
protect against host defences for these parasites
What class are tapeworms
Cestoidea
What are the three regions of cestodes
- Scolex
○ Holdfast
○ Uses this to attach
○ Could have hooks and/or suckers - Neck
○ Constriction - Strobilus
○ Repeating units called proglottids
§ Produced from the neck
○ Proglottids undergo reproduction
§ Gravid
What are gravid protoglottids in tapeworms
Reproductive structures that break down and we have a sack of eggs that are released through the genital pore into the host
What is the one mollusca that does not have an open circulatory system
Cephalopods
Traits uniting mollusca
Snails, bivalves, octopus, squids etc.
Triploblastic, coelomates
Morphologically variable but clearly united
* Head-foot (ventral) and visceral mass (dorsal)
* Mantle and mantle cavity
* Radula (chitinous)
Trochophore larvae
General anatomy of molluscs
Head-foot is like a large muscular structure with a head at one end and the foot at the other
Ventrally there is a visceral mass, covered by the mantle
- Gas exchange
- Secretes a shell
Mantle cavity: forms space between mantle and head-foot
Site of gas exchange
Waste is dumped
In some forms, gametes are released
Gas exchange occurs across gill
What is a radula
Rasping structure
Toothlike, hard structures that scrape food off of surfaces
