1 / 18

The Phylum Ctenophora

The Phylum Ctenophora. Ktenos = comb Phoros = bearing. How do Ctenophores differ from Sponges?. Characteristics of Ctenophora. 8 rows of combs (made of cilia) Radially symmetrical Body consists of two layers with a third layer called mesoglea (jelly-like substance).

azure
Télécharger la présentation

The Phylum Ctenophora

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Phylum Ctenophora Ktenos= comb Phoros = bearing

  2. How do Ctenophores differ from Sponges?

  3. Characteristics of Ctenophora • 8 rows of combs (made of cilia) • Radially symmetrical • Body consists of two layers with a third layer called mesoglea(jelly-like substance)

  4. Characteristics of Ctenophora • Body contains an internal cavity and a mouth and anal pores • No respiratory or circulatory system; simple diffusion • Sexual Reproduction – hermaphrodites • All are carnivorous; capture prey with ten

  5. Benthic (bottom dwelling) Ctenophores • Belong to the Order Platyctenida. • Most are found in warm water; three species have been found on cold, deep sea floor. • Branched tentacles • Look more like sea slugs Valliculamultiformis

  6. Coastal Ctenophores • Order Cydippida • Round or oblong in shape • Usually less than 3 cm (1 inch) in diameter Sea gooseberry Pleurobranchiapileus

  7. Coastal Ctenophores • Order Lobata • Usually larger than cydippids • Pair of highly expandable lobes that are used to capture prey • Short tentacles that remain inside the lobes. Common northern comb jelly Bolinopsisinfundibulum

  8. Coastal Ctenophores • Order Beroida • Elongate animals that may be cylindrical or very flat; grow up to 15cm • More translucent than transparent; colorless or light pink or yellowish Beroe’s comb jelly

  9. Oceanic Ctenophores • Found far off-shore near the surface • More fragile than coastal species • Wing-like Venus’ girdle Cestumveneris

  10. Tortugas red

  11. Ctenophore life cycle • Ctenophores are hermaphroditic, both egg and sperm. • Spawn eggs and sperm freely in the sea where sperm finds the egg and fertilizes it. • Fertilized eggs develop into a larval stage which gradually grows into an adult.

  12. Ctenophore life-scattering/bioluminescence: • Light-scattering is produced by the beating rows of locomatory cilia; light defraction • Most Ctenophores are bioluminescent. Beroe

  13. How do ctenophores fit into the food web? • All ctenophores are carnivores. • Sticky tentacles adhere to small zooplankton prey which is brought across the ctenophore’s mouth.

  14. Ctenophores as marine invaders wreaking ecosystems: • Ctenophores are recognized to be planktonic carnivores • Leidy’s comb jelly (Mnemiopsisleidyi) was introduced into the Black sea and caused a full ecosystem fisheries collapse within less than 10 years • Why? • Outcompeted for plankton Order Lobate

  15. Ctenophores and Medusae (Jellyfish) are they related? • No • Both are plank tonic, carnivorous, often transparent and tentacle bearing • At one time, they were both placed in Phylum Coelenterata but today they are separated. • No polyp stage in Ctenophores

  16. How are Phyla Porifera and Ctenophora similar? Different? Porifera: Sponges Ctenophora: Comb jellies 2 layers: Endoderm Ectoderm with jelly-like middle called the mesoglea Hermaphrodite No digestive or respiratory system Radial symmetry Mobile Carnivorous Cilia Tentacles Bioluminescence Mouth/anal pores Asymmetrical symmetry Sessile Filter feeder Regeneration No true tissues or organs

More Related