Phylum Cnidaria Flashcards
Subphylum Medusozoa: Class Scyphozoa
"Jellyfish" Less 200 species All marine Many quite large Mesoglea is thick, firm gelatin Strobilation
Strobilation
Transverse fission
Asexual reproduction
Spontaneous transverse segmentation of body
Scyphozoa Morphology
Menubrium: opening to mouth
Gastric pouches: allow more digestion; gonads found here
Rhopalia: collection of sensory structures
Class Cubozoa
Box like Medusa. Rhopalia with complex eyes. Less than 25 species. Cubomedusae (medusa stage) dominates. Tropical and sub tropical. Base of 4 tentacles. Most venemous.
Cubozoa Morphology
Velarium: reduces diameter of opening; more water pressure
Base 4 tentacles
Modified eye that creates rudimentary image
Cubozoa reproduction
Adult Planula larvae Creeping polyp Sendentary polyp Medusa
Sexual and asexual by budding
Types of Cubozoa
Box jelly and Caribbean Sea Wasp
Class Hydrozoa
Polyp larger than medusa stage Lack big oral arms Gastrodermis lack nematocysts Mesoglea devoid of cells 3000 species Most marine
Cl Hydrozoa: Subclass Hydroidolina
Most marine, generally medusoid as adults (jellyfish and hydromedusa)
Mostly in surface shallow water
Swim with currents
Cubozoa: Millipora
Fire coral; stings if touched
Hydrozoa: polyp - hydra
Freshwater
No medusa stage
GVC is continuous cavity
Hydrozoa: Order Siphonophore
Portuguese Man of War Colonial Pneumatophore: float like region Nectophore: swim Dactylozooid: stingers
Subphylum Myxozoa
Parasitic (intracellular)
Capsule injects larvae into host cell to develop and rupture to get out and move on.
Capsule similar to nematocyst.
Can cause big impact on fish.
Subphylum Anthozoa
No medusa stage Cnidae lack operculum and cnidocil Circular mitochondrial DNA Siphonoglyph GVC with septa Sea anemone and corals 6000 species
Anthozoa Anatomy
Ring of tentacles, mouth, pharynx, GVC; complete septa (1 mesentery), GVC divided, secondary mesentery incomplete
Siphonoglyphs lined with nematocysts
Acontia: stingers
