Podcast
Questions and Answers
What is the primary body shape of the medusa in the class Cubozoa?
What is the primary body shape of the medusa in the class Cubozoa?
The medusa in the class Cubozoa is box-shaped.
How do sea anemones typically move in their environment?
How do sea anemones typically move in their environment?
Sea anemones glide slowly along using their pedal discs.
What mutualistic relationship exists between clownfish and sea anemones?
What mutualistic relationship exists between clownfish and sea anemones?
Clownfish gain protection from the sea anemones, while they may help ventilate the anemone and keep it free of sediment.
What distinguishes the order Scleractinia from other coral orders?
What distinguishes the order Scleractinia from other coral orders?
Signup and view all the answers
What process do carnivorous corals use to capture their prey?
What process do carnivorous corals use to capture their prey?
Signup and view all the answers
How do cnidarians capture their prey?
How do cnidarians capture their prey?
Signup and view all the answers
What is the role of the gastrovascular cavity (GVC) in cnidarians' digestion?
What is the role of the gastrovascular cavity (GVC) in cnidarians' digestion?
Signup and view all the answers
What distinguishes the locomotion of medusa and polyps in cnidarians?
What distinguishes the locomotion of medusa and polyps in cnidarians?
Signup and view all the answers
Describe the reproductive strategies cnidarians use.
Describe the reproductive strategies cnidarians use.
Signup and view all the answers
What is the significance of cnidarians in their ecosystems?
What is the significance of cnidarians in their ecosystems?
Signup and view all the answers
Study Notes
Marine Biology: Class Cubozoa
- Includes box jellies and sea wasps.
- Medusa is box-shaped and has complex eyes.
- Polyps are small and develop directly into medusae.
Marine Biology: Class Anthozoa
- Includes corals and sea anemones.
- Only exists as polyps (no medusa stage).
- All are marine organisms.
- Can be solitary or colonial.
Marine Biology: Order Actinaria
- Found in coastal waters worldwide.
- Attach to rocks using their pedal disc.
- Feed on fish or other suitable-sized organisms.
- Move by gliding slowly along pedal discs.
- Most withdraw when predators approach.
- Some detach their disc and "swim" away (e.g., Stomphia).
Marine Biology: Structure of Sea Anemones
- Tentacles arranged around the central mouth.
- Gastrovascular cavity divided into six radial chambers.
- Increases the surface area of the gastrodermis.
Marine Biology: Mutualisms
- Sea anemones can harbor zooxanthellae (photosynthetic protists).
- Some crabs decorate their shells with anemones.
- Some damselfish (anemone fish) associate with large anemones.
- Fish gains protection.
- Fish may help ventilate the anemone or remove sediment.
Marine Biology: Order Scleractinia (Hexacorallian Corals)
- True corals or stony corals.
- Like small anemones living in calcareous cups.
- Gastrovascular cavity subdivided by septa (in multiples of six).
- Calcium carbonate skeleton secreted beneath living tissue.
- Polyps may retract into the skeleton.
- Frequently retracted during the day.
- Polyps expand for feeding.
Marine Biology: Order Ceriantipatharia
- Have coupled but unpaired septa.
- Tube anemones are solitary and live in soft sediments.
- Thorny or black corals are colonial and attach to firm substrates.
- Both groups have few species and live in warmer seas.
Marine Biology: Order Octocorallia
- Have eight pinnate tentacles and eight septa.
- Sea fans, sea pens, and sea pansies belong to this group.
- Often beautifully colored
Marine Biology: Feeding
- Cnidarians are carnivores that capture prey using tentacles armed with cnidocytes.
- Nematocysts contain toxins for prey capture and defense.
- Extracellular digestion begins within the gastrovascular cavity, completing within the individual gastrodermis cells.
- Some supplement their diet with nutrients from algal symbionts (zooxanthellae).
Marine Biology: Respiration and Excretion
- Respiration and excretion occur via diffusion.
- Cnidarians' bodies are typically only two cell layers thick.
Marine Biology: Response
- Cnidarians have a diffuse nervous system.
- Nerve cells form interconnected nerve nets within the epidermis and gastrodermis.
- No concentrated grouping of nerve cells forms a central nervous system.
- The nervous system structure is well-suited to their radial symmetry.
Marine Biology: Locomotion
- Medusae are motile and free-swimming.
- Polyps are sessile.
- Exceptions:
- Hydra tumble on tentacles.
- Sea anemones glide on their pedal discs.
Marine Biology: Reproduction
- Cnidarians can reproduce asexually (budding or fission) from polyps or medusae.
- Cnidarians reproduce sexually using sperm and eggs released by medusae.
- Some are monoecious, others are dioecious.
- Larvae are free-swimming (e.g., planula).
- Some species exist only as polyps, others as medusae, and some alternate between the two forms.
Marine Biology: Class Scyphozoa
- Planula larvae develop into polyp-like forms.
- Saucer-like ephyrae are produced via strobilation.
Marine Biology: Ecological Role
- Predators and prey.
- Neurotoxins in medical research.
- Coral used for jewelry, building, and reefs.
- Coral reefs provide habitat for a wide biodiversity of organisms.
- Coral reefs protect coastlines.
- Symbiosis with other organisms.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz explores the unique features and ecological significance of cnidarians, including their structure, movement, and relationships in marine environments. Test your knowledge on medusas, sea anemones, and the various reproductive strategies employed by this diverse group of animals.
