name some of the species in this group
corals, sea anemones, jellies and sea nettles
are they true tissues or do they lack true tissues?
they are true tissues
what kind of symmetry do they display?
radial symmetry
are they sessile or motile?
both. display a wide range of forms
are they diploblastic or triploblastic?
diploblastic and the two layers are separated by a jelly like matrix called a mesoglea
what is interesting about the mouth and the anus?
they are in the same place
explain the nervous system
- no brain
- The nerve net coordinates the movement and the nerve cells interact with sensory and contractile cells
Are they predators or herbivores?
predators
what aids their feeding style?
they have extendable tentacles armed with cnidocyte cells to capture pray which is passed on to the gastrovascular cavity
do they extracellular or intercellular digestion?
extracellular
what are nematocysts?
specialised cnidaria which produce stinging threads that penetrate the body wall of the prey
what are the four classes that cnidaria are divided into?
- Hydrozoa
- Scyphozoa
- Cubozoa
- anthozoa
give an example of a Hydrozoa species
Portuguese man o’war
give a few key features of Hydrozoa group
- normally alternate between polyp and medusa stage
- they live.a colonial lifestyle which mean multiple can combine to make one
- they are highly regenerative
give an example of a Scyphozoa animal
sea nettles
give a few feature of the Scyphozoa group
- true jellies
- all marine
- medusa stage
- shallow coastal
- many are bioluminescent
give an example of a Cubozoa animal
box jellies and sea wasps
give a few feature of Cubozoa group
- all marine tropics
- complex eyes on the fringe
- strong swimmers
- active hunters
- potent venom
give an example of the anthozoa animals
sea anemones, corals- only occur as polyps
