Term | Definition |
5 characteristics of Cnidarians | 1. Radial Symmetry
2. Diploblastic Organization
3. Nematocysts
4. Polymorphism
5. Nerve net |
Diploblastic | Two germ layers |
What are the 2 germ layers? | Ectoderm and endoderm |
Endoderm forms the... | Gastrovascular cavity |
Mesoglea | Jelly-like layer formed from endoderm or ectoderm |
Function of mesoglea | Functions as hydrostatic skeleton |
What are the two main body forms? | Polyp and Medusa |
Usually asexual and sessile; mouth surrounded by tentacles | Polyp Body Form |
Dioecious; free-swimming; has more mesoglea | Medusa form |
Where is the nerve net located? | Just below epidermis |
Function of nerve net? | Detects touch, balance, and engages in photoreception |
Four classes of Cnidaria? | 1. Hydrozoa
2. Scyphozoa
3. Cubozoa
4. Anthozoa |
True Jellyfish | Class scyphozoa |
Box Jellies | Class Cubozoa |
Corals and anemones, sea fans, and sea pansies | Class Anthozoa |
What are the two characteristics of hydrozoa? | 1. Nematocysts are only in the epidermis
2. Medusa has a velum |
Describe the velum | Goes around bottom of organism; almost like a hem at the bottom of the jellyfish to keep the bell from fraying, like blue jeans |
Classification of Obelia | Obelia is a genus in the class Hydrozoa |
Lives in colonial polyp form | Obelia |
Function of hydranth in obelia | Feeding |
Function of nematocysts | Sting prey |
Function of gonangium | Reproduction |
Function of Planula Larva | Disperse |
Order of Obelia life cycle? | 1. Colony
2. Medusa Bud
3. Medusa
4. Planula |
Portuguese Men of War belong to the class.... | Hydrozoa |
What are the 2 important characteristics of class schyphozoa? | 1. Nematocysts occur in epidermis AND gastrodermis
2. Medusa lacks velum |
The genus Aurelia is more commonly known as | Moon jelly |
Is Aurelia monoecious or dioecious? | Dioecious |
Rhopalium | Olfactory and chemo-detection sensory pit found in adult medusa |
Statocyst | Tells Aurelia (moon jellies) if they're upright or not |
Ocelli | In Aurelia, detects light and dark |
Life cycle of Aurelia | 1. Adult Medusa
2. Planula Larva
3. Scyphistoma
4. Strobila
5. Ephyra |
What are the 4 important characteristics of class Cubozoa? | 1. Nematocysts located in gastrodermis and epidermis
2. Venom is cardiotoxic
3. They have a more advanced nervous system
4. Medusa has velarium; tentacles hanging from four corners from a pendalium |
Pedalium | A stalk which bears one or more long, slender, hollow tentacles |
Chironex Fleckeri | A species under the class Cubozoa; highly fatal; 1 chironex could kill 60 people; death in approximately four minutes; causes hypertension, heart failure, and lung edema |
Why are cubozoans so toxic? | Feed on prawn |
What are the 3 important characteristics of class Anthozoa? | 1. Nematocysts occur in gastrodermis and epidermis
2. Venom is neurotoxic
3. No medusa, only polyps |
A ciliated groove at one or both ends of the mouth of sea anemones and some corals; extends into a pharynx and is used to create currents of water into the pharynx | Siphonoglyph |
What do anemones eat? | Fish, worms, and zooplankton |
What kind of skeleton do corals have? | Calcium carbonate |
What type of dinoflagellate helps corals form reefs? | Symbiodinium (zooxanthellae) |
What is the life cycle of Anthozoans? | 1. Polyp adult (produces gametes)
2. Planula larva (grows into adult and cycle repeats) |
Phylum Ctenophora | Comb jellies |
How are Ctenophora similar to Cnidaria? | They both have diploblastic body walls, radial symmetry, and epidermal nerve nets |
Adhesive cells on tentacles used to capture prey in Ctenophora | Colloblasts |