Flashcards in Cnidaria Deck (18)
What creates are in the cnidaria phylum?
Jellysofh and corals
How many species?
What symmetry do they display?
Diplo or triplo blastic?
What are the common features?
Simple form, mouth =anus, No brain but simple NS
contractile bundles of microtubules act like muscles
What are the two forms?
Medusa - mouth down and Polyp
What clade do they belong to?
What is the basic body plan?
Central gastrovascular cavity, single opening
What mode of life in polyps?
Sessile, adhere to substrate by aboral end
What mode of life in medusa?
Motile, moves by drifting and contraction
How do they feed?
Carnivores, use tentacles and mouth to catch prey
What are cnydocytes?
Cells unique to cnidarians that function in prey capture - contain cnidae, capsule like organelles that are capable of exploding out
What are nematocysts?
Specialised cnidae that contain stinging thread to paralyse
What are the 4 classes?
Hydrozoans, scyphozoans, cubozoans, anthozoans
Describe the Hydrozoans
alternate between forms, some found in freshwater, reproduce sexually and asexually, very diverse group
Describe the Scyphozoans
medusa generally dominant - known as true jellyfish, some go through stage as small polyps
Describe the Cubozoans
box shaped medusa stage. complex eyes embedded in the fringe, compositely strong swimmers, highly toxic