Diversity of RadiataCasey, Brigid, Dory, Lawrence, Jess

Phylum Ctenophora

● do not produce nematocysts (but can have them from eating Cnidaria)

● have comblike plates of cilia they use for locomotion

● mainly free swimming with some creeping and sessile forms

● about 150 species

Anthozoa

Corals:-Soft Corals: sea whips, sea fans and gorgonians. Colonial polyps. Skeletons of CaCO3 spicules/ tough protein sheath. 8-sided symmetry. Gastrovascular cavity divided into units of 8.-Hard Corals: “reef builders”. Skeleton is CaCO3. Gastrovascular cavity split into multiples of 6 parts. Colonial polyps.

Sea Anemones: -Gastrovascular cavity also split into 6 parts. Polyp stage. Have stinging cells. More than 1000 species found throughout the world.

Cubozoa

● Similar to scyphozoans, but have a box-like medusa body

● Four evenly spaced tentacles (Carybdeids) or four bunches of tentacles (Chirodropids)

● Well-developed eyes and vision● Velarium- helps the jellyfish move more rapidly● 20 known species, found in mostly tropical and

semitropical waters

● Marine and colonial (in form)● lifecycle:

○ Asexual polyp & sexual medusa stages○ Exceptions to exist

● Freshwater hydrozoan:○ Solitary polyp ○ mouth: hypostome-surrounded by tentacles that extend

■ chemical activator= glutathione causes mouth to open○ Asexual budding- outpocketing from body wall

● Hydroid Colonies:○ Medusa stage○ has base, stalk, and one or more terminal polyps○ Mouth- end of suspended manubrium leads to a stomach and

four radial canals● Other Hydrozoans

○ Siphonophores- floating colonies○ hydrocorals-secrete massive calcareous skeletons that look

like true corals

Hydrozoa

Scyphozoa

-A very broad class that includes some of the largest jellyfish ranging up to 3 meter diameter.

-Scyphozoa derives from the greek word for “drinking cup”

-Has two life stages: Sedentary polyps, and planktonic medusae which mature into adult jellyfish.

-Medusa of the class Scyphozoa have no velum unlike many other Radiata.

Class Staurozoa

● life cycle does not include a medusa phase● structure

○ solitary polyp is stalked and attaches to seaweed and other objects on the seafloor using an adhesive disk

○ top of polyp has eight arms ending in tentacle clusters

● polyps reproduce sexually ● all marine