Which organisms are classified as "cnidarians"?
sea jellies, sea anemones, corals
Where does the word cnidaria derive from?
Greek meaning stinging needle
What are the general characteristics of a cnidarian?
- radial symmetry
- only one opening for the mouth and anus
- stinging cells
- more complex than sponges
what are the two main tissue layers for a cnidarian? and what's in between that?
- epidermis: outer layer
- gastrodermis: inner layer
- Mesoglea: jelly like substance
what is the body form of a medusa?
umbrella like body with tentacles
what's the body form of a polyp?
tube shaped body with tentacles
what class does sea anemones and corals belong to?
portugese man of war and hydroids
cube jellies/ box jellies
give characteristics of a sea anemone and what class?
- -polyp shape
- -lives in rocky intertidal and reefs
what type of relationship do sea anemones have?
clownfish, snapping shrimp, crabs, hermit crabs
give characteristics of a coral and which class?
- -polyp shape ONLY
- -secretes a skeleton of calcium carbonate
- -usually found in warmer, tropicsl waters
describe the coral and algea symbiosis
corals have a mutualistic relationship with zooxanthellae since the algea makes food for the coral and the coral provides protection and other nutrients to the algea
give characteristics of sea jellies and which class?
- -exists in both body forms but medusa is predominant body plan
- -open water drifter
- -medusa shaped
- -swims with rhythmic contraction called "undulation'
give characteristics of hydroids and which class?
- -often a colonia organism
- -can exist as polym or medusa (i.e. the portugese man of war)
- -some sessile and some drifters
what's coral bleaching?
- when the coral lose their zoocanthellae (algea) found int he polyps.
- the coral loses its color and becomes white due to the calcium carbonate skeleteon.
- Bleaching due to stress, pollution, enviornmental conditions...etc.
How do cnidarians, polyp shaped, and medusa shaped reproduce?
- cnidarians: both sexually and asexually
- polyp shape: asexual
- medusa: sexual
what are stinging cells
- Harpoon like.
- Located at the tentacles used to stun or poison their prey.
what are the symptoms of a jelly fish sting?
burning, swelling, headaches, dizziness, paralysis and or death.
where is the box jelly found? What are they to a human being?
- australia, philippines, hawaii, and other tropical areas.
- the most lethal jelly which can cause death within minutes
what's the other phylum ter formerly used to classify cnifarians?
what's an example of a siphonophore?
which class of cnidarians has the most species?
cnidarians capture food?
using fluid and tread would stick to prey.
what's the function of the septa?
provides additional surface area
how do stinging cells work?
they work by hacing tentacles sting/poison anything that came in its contact.
what's coral bleaching?
zooxanthellae found in the polyps leave the coral, thus starves the coral and yeah
how is the digestive system of a cnidarian different from a human>
digestion takes place outside
what's a planula?
characteristic of larva for most of cnidarians