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