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Phylum Platyhelminthes - Phylum Brachiopoda
Marine “Worms” and False Clams
Phylum Platyhelminthesincludes flatworms, tapeworms and flukes
bilateral symmetry
body flattened dorsoventrally (back and front)
Class Turbellaria: marine flatworms
not parasitic
move by cilia and/or slime trail
found in benthic habitats
have Ocelli (light sensitive eyespots)
can regenerate!!!
Very Strange ReproductionPenis Fencing
Phylum Nemertinaincludes ribbon worms
small, inconspicuous worms
live in shallow water, benthic environments, often found in mussel beds
complete digestive tract - first animal with mouth and anus
have a proboscis - for defense and gathering food
elastic worms can stretch, but break into pieces with the slightest disturbance - can regenerate
Phylum AnnelidaBilateral Symmetry
Closed Circulatory System!!!
Have Segments - internal and external
Each segment has Parapodia (used for crawling, swimming, anchoring in tubes)
also have Setae - bristles used for locomotion
allows for “peristalic contractions”
Phylum AnnelidaClass Polychaeta
marine worms
can be pelagic - enlarged parapodia for swimming (Errant Polychaetes)
can be benthic and crawl
can be sessile - live in tubes (Sedentary Polychaetes)
some are commensal and live within other organisms-sea stars, limpets
can be filter feeders or aggressive predators with a proboscis
Phylum AnnelidaErrant Polychaete examples:
Nereis: Clam Worm
can be 30-40 cm long
live in mucus lined burrows near low tide
seizes prey through jaws which are pushed through mouth via the pharynx - think “Alien”
Phylum Annelida
Fire Worms
hollow Setae with poisonous secretion
when touched setae break off and cause irritation
Scale Worms
flattened bodies
carnivores
More Errant examples