Cnidarians & Ctenophorans Flashcards
1
Q
Where are hydras found?
A
Freshwater
2
Q
What are characteristics of cnidarians?
A
- Radial symmetry
- Hollow gut
- Gastrovascular cavity has a single opening
- Two tissue layers (diploblastic)
- Outer epidermis and inner gastrodermis
- Either polyp or medusa shaped
- Tentacles surround mouth
3
Q
Part 2 of cnidarian characteristics
A
- cnidocytes contain poison to paralyze prey
- Tentacles bring food into mouth
- Inner gastrodermis secretes digestive juices into gastrovascular cavity which digests food and circulates nutrients
4
Q
Describe cnidarian systems
A
- has a simple nerve net & sensory receptors
- muscles help in directional movement & capturing prey
- jelly like mesoglea between two cell layers supports cnidarian
5
Q
What are the two main body plans?
A
Polyp and Medusa
6
Q
What are characteristics of sea anemones?
A
- Brightly colored and resemble flowers
- Solitary polyps
- Feed on invertebrates and fish
7
Q
What are characteristics of coral?
A
- Most are colonial
- Build limestone case
- Live as polyps in their case
8
Q
What are characteristics of hydra?
A
- Exist only as polyps (no medusa form)
- Reproduce by budding
- Freshwater only
- Form resistant zygotes when environment is bad
- Move by somersaulting with tentacles
9
Q
What are characteristics of PMOW?
A
- Colonial hydrozoan
- Tentacles sting prey
- Polyps in colony feed
- Has gas filled air float
10
Q
What are characteristics of a jellyfish?
A
- Medusa is dominant body form
- Go through small polyp stage during life cycle
- Stinging tentacles
- May live close to shore or open ocean
11
Q
What are characteristics of ctenophorans? (comb jellies)
A
- all marine
- approximately 100 species
- may be spherical, ovoid, or elongate
- radial symmetry
- most of the body is jelly-like mesoglea
- body and tentacles covered with sticky mucus to catch prey
