Cnidarian I Flashcards
What are the different types cnidarians?
- some are pelagic, swim in the open ocean
-some are benthic, meaning they are on the ocean floor
-some are sessile, they attach to a substrate
How do cnidarians protect themselves?
stings
What are the synamorphies of Cnidarians?
Cnidocytes: they are larges cells that are under pressure. upon contact they will explode. they can have glues, poisons, and entangling threads.
What is radial symmetry?
no matter how you cut a circle, it always ends up with two equal parts?
Who are the only ones to have radial symmetry? Why?
Cnidarians; allows to them to have more access to food around them because they don’t move.
What type of symmetry is most common for cnidarians?
4 equal parts
What is dimorphism?
2 forms. polyps which gives rise to medusa, which gives rise to larva, which gives to polyps
What is polymorphism?
colonel polyps that differentiate into different forms/jobs
what do gastrozooids specialize in?
digestion
what do dactylozooids specialize in?
tentacles for defense
what do gonozoids specialize in?
reproduction
What is the community ecology of Cnidarians?
multiple species interacting with each other, habitat creators such as coral reefs
what does velum do?
helps give the jelly fish support and structure
where does absorption occur?
in the gastrovascular cavity,
what does the ring canal do?
takes nerves and nutrients all a round the rim of jellyfish
what does manubirum do?
connects the mouth to the gastrovascular cavity
what does the life cycle of obelia contain?
asexual and sexual life functions. grows asexually but will grow into may different parts
what is the coenosarc?
living part of the animal; has nutrients which transport it around the organism. secretes the Persiac for protection
what are hydocroals and why are they classified in the Hydrozoa?
they do not secrete medusa, but have a calcium based skeleton to live in. seen in the hard coral anthozoa
scyphozoan morphology?
larger jellyfish, sometimes the largest in the ocean. long lappets. umbrella margin is scalloped. the jelly part of the jellyfish is the mesoglea
What is the mesoglea?
most nonliving, gelatinous gastric, that are home to ameboid cells.
What occurs wherever the scallops meet? Why?
Rhopalia. important area for sensing. includes ocelli and statocysts.
what does ocelli do?
light sensitive cells that are good at detecting motion
what are statocysts?
cilium with a gelatinous membranes with a rock inside. the rock is made up of calcium or silica. the rock floats until it his the cilium to that sends a nervous signal
