marine invertebrate zoology n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Marine Invertebrate Zoology PowerPoint Presentation
Download Presentation
Marine Invertebrate Zoology

Loading in 2 Seconds...

play fullscreen
1 / 36

Marine Invertebrate Zoology - PowerPoint PPT Presentation


  • 290 Views
  • Uploaded on

Marine Invertebrate Zoology. The Hydrostatic Skeleton Phylum Cnidaria. The Hydrostatic Skeleton. The Hydrostatic Skeleton. The hydrostatic skeleton requires:. Phylum Cnidaria Overview. Defining Characteristics Formation of complex intracellular organelles called nematocysts

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 'Marine Invertebrate Zoology' - lotus


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
marine invertebrate zoology

Marine Invertebrate Zoology

The Hydrostatic Skeleton

Phylum Cnidaria

Phylum Cnidaria

the hydrostatic skeleton1
The Hydrostatic Skeleton
  • The hydrostatic skeleton requires:

Phylum Cnidaria

phylum cnidaria overview
Phylum Cnidaria Overview
  • Defining Characteristics
    • Formation of complex intracellular organelles called nematocysts
    • Planula larvae in the life cycle
  • The phylum is composed of anemones, corals, sea whips, hydroids, and jellyfishes
  • Diploblastic

Phylum Cnidaria

diploblastic animals
Diploblastic Animals
  • Epidermis
  • Gastrodermis

Phylum Cnidaria

nematocysts
Nematocysts
  • Used for gathering food or defense
  • Produced in special cells called cnidoblasts

SEM micrograph of nematocysts penetrating skin

Phylum Cnidaria

nematocysts1
Nematocysts

Phylum Cnidaria

cnidarian nutrition
Cnidarian Nutrition
  • A major cnidarian drawback is the absence of an anus
  • Carnivorous feeders on zooplankton and small fish
  • Reef building corals also depend on symbiotic photosynthetic dinoflagellates for energy

Phylum Cnidaria

reproduction and nervous system
Reproduction and Nervous System
  • Reproduce asexually and sexually
    • Larvae - mouthless, ciliated, swimming planula
  • In the classes Scyphozoa and Hydrozoan the sexual stage is the medusa
    • Alternate between the polyp and medusa
    • The polyp asexually produces a medusa that sexually produces a planula larvae, which then settles into a polyp
  • Polymorphism = more than one stage per species

Phylum Cnidaria

polyp and medusa
Medusa (jellyfish)

Usually solitary and free swimming

The mouth and tentacles are directed downwards

Contains thick mesoglea

Polyp (tube shape)

Solitary or colonial, usually sessile attached by its base

Mouth and tentacles are pointed upward

Mesoglea is usually thin

May have a fluid skeleton or calcium carbonate exoskeleton

Polyp and Medusa

Phylum Cnidaria

cnidarian classification
Cnidarian Classification
  • Phylum Cnidaria
    • Class Scyphozoa
    • Class Cubozoa
    • Class Hydrozoa
      • Order Hydroida
      • Order Siphonophora
    • Class Anthozoa
      • Subclass Alcyonaria (Octocorallia)
      • Subclass Zoantharia (Hexacorallia)

Phylum Cnidaria

class scyphozoa
Class Scyphozoa
  • Defining characteristic
    • Asexual replication by strobilation
    • Includes the true jellies, moon jellies (Aurelia) and Sea Nettles (Chrysaora)

Phylum Cnidaria

scyphomedusa structure
Scyphomedusa Structure
  • Contains a large swimming bell that has tentacles and sensory capsules
    • Rhopalia
      • Statocysts
      • Ocelli

Rhopalia

Phylum Cnidaria

medusa movement
Medusa Movement

Phylum Cnidaria

scyphomedusa structure1
Scyphomedusa Structure

Phylum Cnidaria

class cubozoa
Class Cubozoa
  • Defining characteristics
    • Medusa with box-like body
  • Chiropsalmus quadrumanus (Sea Wasp)

Phylum Cnidaria

class cubozoa1
Class Cubozoa
  • Known as box jellies or sea wasps due to shape and painful sting
  • Occur in tropical and warm temperate seas

Cubozoa Eyes

Phylum Cnidaria

class hydrozoa
Class Hydrozoa
  • Due too small sizes and plant-like appearance people are unaware of their existence
  • Display both polyp and medusa in the life cycle
  • Mesoglea is thin or absent

Phylum Cnidaria

hydroid structure
Hydroid Structure
  • Polyps can be solitary or colonial
  • Very drab in appearance, no external skeleton, colonies are polymorphic

Hydra

Phylum Cnidaria

polymorphism
Polymorphism
  • Hydroid colonies have polyps of different functions
    • Feeding - gastrozooids
    • Defense - dactylozooids
    • Reproduction - gonozooids

Phylum Cnidaria

hydromedusa structure
Hydromedusa Structure

Phylum Cnidaria

hydrozoan reproduction
Hydrozoan Reproduction
  • Hydroid stage can reproduce by asexual budding
    • Eventually the bud detaches and becomes independent
      • Also has considerable powers of regeneration
  • Gonozooids will release medusa
    • All medusa reproduce sexually

Phylum Cnidaria

order hydroida
Order Hydroida
  • Most species of the class hydrozoa in our area are hydroids
  • Form sessile colonies of polyps and are usually mistaken as seaweed
    • Exceptions are Velella and Porpita = hydroids that float freely at the surface

Velella

Phylum Cnidaria

order siphonophora
Order Siphonophora
  • Swimming or floating hydrozoan colonies
  • Portuguese man-o-war (Physalia physalis)

Phylum Cnidaria

class anthozoa
Class Anthozoa
  • Defining characteristics
    • Absence of a medusa stage
  • Anemones, corals, sea whips, sea pansies
  • Polyps consists of a column, flattened oral disk surrounding the mouth which bears tentacles
  • Some polyps are solitary (anemones) others are colonial (coral)

Phylum Cnidaria

class anthozoa1
Class Anthozoa
  • Feed using tentacles that move food to the mouth
  • Water is used by some as a fluid skeleton
  • Produce planula larvae that settle and form new colonies
  • Can also reproduce using pedal laceration and fission

Phylum Cnidaria

subclass zoantharia hexacorallia
Subclass Zoantharia (Hexacorallia)
  • Posses 6 septa that separate the gastrovascular cavity
  • Many species are solitary and lack a protective covering (sea anemones)
  • Separated into two major orders

Phylum Cnidaria

sea anemones
Sea Anemones
  • Solitary and lack a rigid skeleton
  • Have a broad adherent pedal disk
  • Can reproduce asexually (pedal laceration) and sexually

Phylum Cnidaria

stony corals
Stony corals
  • Colonial with calcium carbonate skeleton secreted by the epidermis
  • May be reef-building (hermatypic) or non reef building (ahermatypic)
  • Hermatypic corals live in warm clear waters and can form chains around islands
    • Zooxanthellae forms a symbiotic relationship with coral

Phylum Cnidaria

subclass alcyonaria octocorallia
Subclass Alcyonaria (Octocorallia)
  • Distinguishing characteristics
    • Sea whips, sea fans, and sea pansies are in this group
    • Can harbor zooxanthellae

Phylum Cnidaria