slide1
Download
Skip this Video
Download Presentation
Introduction to Cnidaria Jellyfish, corals, and other stingers. . .

Loading in 2 Seconds...

play fullscreen
1 / 14

Introduction to Cnidaria Jellyfish, corals, and other stingers. . . - PowerPoint PPT Presentation


  • 125 Views
  • Uploaded on

Introduction to Cnidaria Jellyfish, corals, and other stingers. Cnidarians are incredibly diverse in form Yet, these diverse animals are all armed with stinging structures called nematocysts (cnidocytes) The name Cnidaria comes from the Greek word "cnidos“

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Introduction to Cnidaria Jellyfish, corals, and other stingers. . . ' - palmer-castro


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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide2

Cnidarians are incredibly diverse in form

  • Yet, these diverse animals are all armed with stinging structures called nematocysts (cnidocytes)
  • The name Cnidaria comes from the Greek word "cnidos“
  • Many thousands of cnidarian species
slide3

Fossil Records

  • A few mineralized coral-like fossils have turned up in the Cambrian Period
  • Identifiable corals began an evolutionary radiation in the Early Ordovician
  • Scleractinian corals appeared in the Middle Triassic, about 15 million years after the Permian extinction.
slide4

Scleractinian became the dominant hermatypic (reef-building) organisms in shallow tropical marine habitats.

  • Corals are sensitive to changes in light, temperature, water quality, and salinity
slide5

Cnidarian TAXONOMY

  • There are four major groups of cnidarians:
  • Anthozoa, which includes true corals, anemones, and sea pens;
  • Cubozoa, the amazing box jellies with complex eyes and potent toxins;
  • Hydrozoa, the most diverse group with siphonophores, hydroids, fire corals, and many medusae; and
  • Scyphozoa, the true jellyfish.
slide7

CNIDARIAN Morphology

***Versus polyp

slide8

Features:

  • Two tissue layers with nerve and muscle tissues
  • Nematocysts: structures contained in special cells called cnidocytes or cnidoblasts that can act in both offense and defense
  • Two main life forms: free-swimming medusa (e.g., jellyfish) or stationary polyp (e.g., anemone)
slide9

Introduction to the Anthozoa

  • Anthozoans are probably the most famous cnidarians: they include the corals that build great reefs in tropical waters, as well as sea anemones, sea fans, and sea pens.
  • True corals living today did not appear until the middle Triassic, at about the same time that the first dinosaurs were evolving
slide10

Introduction to Cubozoa:The Box Jellies

  • They look like your basic jellyfish, but they can swim pretty fast, maneuver around things, and see fairly well despite not having a brain.
  • Cubozoans have a square shape when viewed from above.
  • They also have four evenly spaced out tentacles or bunches of tentacles and well-developed eyes
  • Chironex fleckeri
slide11

Introduction to the Hydrozoa

  • The best-known hydrozoan is Hydra. Hydra never goes through a medusoid stage, and spends its entire life as a polyp.
  • Most hydrozoans alternate between a polyp and a medusa stage -- they spend part of their lives as "jellyfish" which are hard to distinguish from scyphozoan jellyfish.
  • The "Portuguese man-o\'war" and "by-the-wind-sailors" that often wash up on beaches are examples of these unusual colonial hydrozoans.
slide12

Introduction to the Scyphozoa

“the true jellyfish”

  • Scyphozoans include most of the jellyfish other similar organisms
  • Their stings may cause skin rashes, muscle cramps, or even death.
  • Jellyfish range in size from a mere twelve millimeters to more than two meters across.
  • The largest is Cyanea arctica, which may have tentacles over 40m long!
ad