BIOL 300 Lab 9: Lophotrochozoans Definitions & Terms

Lohotrochozoans

protostome group with bilateral symmetry
has either trocophore or locophore or both

Trocophore

planktonic largal stage

Locophore

tuft-like structure that surrounds mouth for feeding

True coelom

A body cavity completely lined with tissue derived from mesoderm.

Acoelomate

flatworm with no body cavity

Psuedocoelomate

roundworm have a functional body cavity NOT fully lined with mesoderm.

Coelomate

earthworm and possesses a true coelom

Phylum Rotifera characteristics

as small as unicellular protists, triploblastic pseudocoelomates

How do phylum rotifera attract prey

Corona (crown) of cilia beat in synchrony to draw in prey

Phylum Rotifera anatomy

full gut for digestion
strictly asexual reproduction
beat cilia to move

Phylum Platyhelminthes

Flat worms, triploblastic acoelomates, 2- way digestive tract

Classes of Platyhelminthes

1. Turbellaria
2. Trematoda
3. Cestoda

Class Turbellaria

planaria
mostly non parasitic and marine
predatory or scavengers
ciliated body surfaces

Class Trematoda

common name: flukes
obligate parasites
- mostly vertebrate hosts
- attaches to host with suckers
causes schistosomiasis in humans
- most serious human parasitic infection after malaria

Class Cestoda

common name: tapeworms
endoparasitic: vertebrate hosts
scolex with hooks and suckers
strobila: main body
consists of proglottids (body segments containing male and female repro. sys)
no head & no digestive system
gravid proglottid separate to disperse offsprings

Phylum Annelida

coelomates, metamerism, setae

metamerism

each segment contains a separate excretory, nervous, and circulatory system

setae

external bristles that grip substrates

Class Obligochaeta

earthworms, belonging to Phylum Annelida

Phylum Mollusca

mostly marine
soft bodied
some have calcium carbonate shell

visceral mass

collection of internal organs

mantels

dorsal body wall of all molluscs

foot

muscle for moving

What class belongs to Phylum Mollusca

Class Cephalopoda

organisms within class cephalopoda

octopi, squid, nautilusesm cuttle fish

class cephalopoda characteristics

high speed ocean predators
- arms tentacles or fins

efficient circulatory and gas exchange system
- breathe with gills

highly developed nervous system

what class cephalopoda organism has a closed circulatory system

mollusks