Indirectly Asked Questions and Answers on
Phylum Ctenophora
SECTION A: GENERAL CHARACTERISTICS AND BODY
ORGANIZATION
1. Ctenophores are called comb jellies due to eight rows of ciliary comb plates (ctenes) that refract
light.
2. Distinguishing features: marine, transparent, biradial symmetry, diploblastic with muscle cells,
colloblasts for prey capture, comb rows for locomotion, bioluminescent, no nematocysts.
3. Biradial symmetry differs from radial symmetry in Cnidaria; represents advancement.
4. Mesoglea is muscular and functional, enabling contraction and movement.
5. Transparency and buoyancy come from water-rich mesoglea.
SECTION B: ANATOMY, STRUCTURE, AND PHYSIOLOGY
6. Colloblasts are adhesive cells used to capture prey.
7. Locomotion by eight rows of beating cilia (ctenes).
8. Statocyst functions as balance organ coordinating movement.
9. Digestive tract complete (mouth to anal pores), unlike Cnidaria.
10. Ctenophores are advanced diploblasts with mesogleal muscles, complete gut, and statocyst.
11. Bioluminescence aids in defense, prey attraction, and communication.
SECTION C: REPRODUCTION AND DEVELOPMENT
12. Hermaphroditic reproduction, mostly external fertilization.
13. Development direct via cydippid larva, resembling adult.
14. High regeneration ability allows repair of comb plates and tentacles.
SECTION D: CLASSIFICATION AND EXAMPLES
15. Two classes: Tentaculata (e.g., Pleurobrachia, Cestum) with tentacles; Nuda (e.g., Beroe)
without tentacles.
16. Pleurobrachia typical ctenophore: transparent, two tentacles, eight comb rows, mouth, and anal
pores.
17. Cestum (Venus girdle) differs by ribbon-like body and large size.
SECTION E: ECOLOGICAL AND EVOLUTIONARY SIGNIFICANCE
18. Ecological roles: control zooplankton, serve as prey, aid nutrient cycling.
19. Invasive species like Mnemiopsis leidyi disrupt ecosystems and fisheries.
Phylum Ctenophora
SECTION A: GENERAL CHARACTERISTICS AND BODY
ORGANIZATION
1. Ctenophores are called comb jellies due to eight rows of ciliary comb plates (ctenes) that refract
light.
2. Distinguishing features: marine, transparent, biradial symmetry, diploblastic with muscle cells,
colloblasts for prey capture, comb rows for locomotion, bioluminescent, no nematocysts.
3. Biradial symmetry differs from radial symmetry in Cnidaria; represents advancement.
4. Mesoglea is muscular and functional, enabling contraction and movement.
5. Transparency and buoyancy come from water-rich mesoglea.
SECTION B: ANATOMY, STRUCTURE, AND PHYSIOLOGY
6. Colloblasts are adhesive cells used to capture prey.
7. Locomotion by eight rows of beating cilia (ctenes).
8. Statocyst functions as balance organ coordinating movement.
9. Digestive tract complete (mouth to anal pores), unlike Cnidaria.
10. Ctenophores are advanced diploblasts with mesogleal muscles, complete gut, and statocyst.
11. Bioluminescence aids in defense, prey attraction, and communication.
SECTION C: REPRODUCTION AND DEVELOPMENT
12. Hermaphroditic reproduction, mostly external fertilization.
13. Development direct via cydippid larva, resembling adult.
14. High regeneration ability allows repair of comb plates and tentacles.
SECTION D: CLASSIFICATION AND EXAMPLES
15. Two classes: Tentaculata (e.g., Pleurobrachia, Cestum) with tentacles; Nuda (e.g., Beroe)
without tentacles.
16. Pleurobrachia typical ctenophore: transparent, two tentacles, eight comb rows, mouth, and anal
pores.
17. Cestum (Venus girdle) differs by ribbon-like body and large size.
SECTION E: ECOLOGICAL AND EVOLUTIONARY SIGNIFICANCE
18. Ecological roles: control zooplankton, serve as prey, aid nutrient cycling.
19. Invasive species like Mnemiopsis leidyi disrupt ecosystems and fisheries.
