zoology cnidaria
TRANSCRIPT
-
7/31/2019 Zoology Cnidaria
1/46
Phylum Cnidaria
Common Name: None
a.k.a.coelenterata
Examples: Hydra, jellyfish, coral,
Portuguese man of war, sea anemone
-
7/31/2019 Zoology Cnidaria
2/46
Phylum Cnidaria
A. Gr. knide nettle) + L. aria, -like
B. ny dar' e-a
D. 9,000 species.
E. Odd name = ph. Coelenterata, early 1900'sF. coelenterate = Cnidaria + Ctenophora
G. Metazoans, have tissue but organs poorly defined
H. Tentacles present, can be fused
I. Mouth(=anus), digestive area = gastro-vasula cavity(GV)
J. Body can have covering skeleton, 98% of body isK. Diploblastic ; 2 tissue layers(=ectoderm & endoderm) during
gastrula stage
L. In marine & fresh water
-
7/31/2019 Zoology Cnidaria
3/46
Cnidaria - Morphology and
DigestionE. Radial or Biradial symmetry
F. Gastrovascular cavity
G. Most small; colonial organisms may be themost massive on Earth
H. Tissue level of organization, a few organs
I. Extracellular digestion in
gastrovascular cavity intracellular ingastrodermal cells
-
7/31/2019 Zoology Cnidaria
4/46
-
7/31/2019 Zoology Cnidaria
5/46
Cnidaria Excretion, Nervous
System & LocomotionJ. Simple excretion
K. Simple respiration by diffusion
L. Nerve cells and nerve netM. Sense organs (statocysts and ocelli)
N. Some can swim by jet propulsion orthrough cilia
O. Polymorphism in some species -medusa and polyp
-
7/31/2019 Zoology Cnidaria
6/46
-
7/31/2019 Zoology Cnidaria
7/46
Cnidaria Skeleton and Reproduction
P. hydroskeleton or exoskeleton orendoskeleton
Q. Reproduction can be sexual orasexual1. Asexual reproduction by budding in
polyps
2. Sexual reproduction by gametes in allmedusae, some polyps
3. Sexual forms monecious or dioecious
4. Planula larvae
-
7/31/2019 Zoology Cnidaria
8/46
Reproduction
Hydra Warm: Asexual (budding)
Dropping Temp triggers sexual
Jellyfish Polyps are asexual
Medusa are sexual
Hermaphrodite Anemone, mostly
Produce both egg and sperm
fr.wikipedia.org
www.dpo.uab.edu
-
7/31/2019 Zoology Cnidaria
9/46
Reproduction
Individual Jellyfish are either male or female. The eggsand sperm develop in very colourful special areas called'Gonads' inside the body wall. When all of the eggs and
sperm are fully developed, they are released into thestomach and then through the mouth into the sea. In mostcases, to reproduce, a male jellyfish releases his sperminto the surrounding water. The sperm then swims into themouth of the female jellyfish, allowing the fertilization of
the ova process to begin. Moon jellies, however, use adifferent process: their eggs become lodged in pits on theoral arms, which form a temporary brood chamber toaccommodate fertilization.
-
7/31/2019 Zoology Cnidaria
10/46
Reproduction
When the eggs are released into the sea they are
fertilized by the sperm and continue to develop.As in all many-celled animals, the microscopicfertilized eggs begin a series of cell divisionswhich finally result in an embryo. However, theembryo does not develop directly into a baby
jellyfish, but becomes a tiny, flattened creaturecalled a 'Planula'.
The Planula, which is covered with rapidlybeating hairlike cilia (thin, tail-like projections), isable to swim and may be carried a considerabledistance by ocean currents during its shortswimming period, lasting from a few hours toseveral days. The tiny Planula then makes its waytoward the sea bottom where it actively looks fora suitable place to attach itself. At this point, aamazing series of events take place.
-
7/31/2019 Zoology Cnidaria
11/46
Reproduction
The tiny Planula floating
in the sea. Searching for a place toattach itself.
Once attached, it feedson passing, floating food.
At this stage, the Polypsmouth and tentacles are
facing upwards. Grooves appear and
become deeper,eventually cuttingthrough the Polyps body.
A pile of disc-shaped
structures emerge andbreak away. Each being ababy Jellyfish.
At this stage it is called aMedusa and is theJellyfish form werecognise in our oceans.
-
7/31/2019 Zoology Cnidaria
12/46
Cnidaria - Ecology
R. Mostly marine, some freshwater
S. Mostly freeliving
T. Feed by capture of prey;endosymbionts
1. Cnidocytes - stinging cellscontaining nematocysts
-
7/31/2019 Zoology Cnidaria
13/46
Nutrition: sting prey with nematocysts,push food into mouth with tentacles.
www.palaeos.com
www.jcu.edu.au
-
7/31/2019 Zoology Cnidaria
14/46
The freshwater hydra is asimple organism with a basal
suction disk or foot, and apicaltentacles.
-
7/31/2019 Zoology Cnidaria
15/46
Nematocyst
-
7/31/2019 Zoology Cnidaria
16/46
-
7/31/2019 Zoology Cnidaria
17/46
Cnidaria Evolution and
TaxonomyU. Cnidarians from
ancestral radially symmetrical
planula larvaV. 4 Classes:
1. Hydrozoa
2. Scyphozoa
3. Cubozoa
4. Anthozoa (
-
7/31/2019 Zoology Cnidaria
18/46
Class Hydrozoa
a) Gr. Hydra - water serpent + zoon, animalb) Hi-dro-zo'-a
c) Dominated (in most) by the polyp form
d) Mostly marine, mostly colonial
e) 2,700 species
-
7/31/2019 Zoology Cnidaria
19/46
universe-review.ca
-
7/31/2019 Zoology Cnidaria
20/46
-
7/31/2019 Zoology Cnidaria
21/46
-
7/31/2019 Zoology Cnidaria
22/46
-
7/31/2019 Zoology Cnidaria
23/46
-
7/31/2019 Zoology Cnidaria
24/46
-
7/31/2019 Zoology Cnidaria
25/46
-
7/31/2019 Zoology Cnidaria
26/46
Class Scyphozoa
Gr. skyphos, cup + zoon, animal
Si-fo-zo'-a
dominated (in most) by the medusa form(1) polyp (strobila) form
free-swimming medusa
some (Cassiopeia) with endosymbionts
200 species
-
7/31/2019 Zoology Cnidaria
27/46
-
7/31/2019 Zoology Cnidaria
28/46
Cassiopeia, the upside-down
jellyfish, harbors endosymbiontswhich photosynthesize. Laying
upside-down in sunny areas bringslight to the endosymbionts.
-
7/31/2019 Zoology Cnidaria
29/46
Class Cubozoaa) Figure 13-20 (266)
b) Gr. Kybos, cube +zoon, animal
c) Ku' bo-zo' ad) dominated (in most) by
the medusa form
e) about 100 species
-
7/31/2019 Zoology Cnidaria
30/46
Class Anthozoa
Gr. Anthos, flower, zoon, animal
An-tho-zo' a
all polyps - no medusae all marine
6000 species
-
7/31/2019 Zoology Cnidaria
31/46
3 main groups of
anthozoans:(1) Sea anemones and hard
corals
(2) tube anemones and thornycorals
(3) soft corals, horny corals, sea
fans, sea pens, sea pansies
-
7/31/2019 Zoology Cnidaria
32/46
-
7/31/2019 Zoology Cnidaria
33/46
Anenomes are exclusivelymarine, as are all anthozoans.
-
7/31/2019 Zoology Cnidaria
34/46
-
7/31/2019 Zoology Cnidaria
35/46
Rather than stinging, sunanenomes stick to their prey.
-
7/31/2019 Zoology Cnidaria
36/46
-
7/31/2019 Zoology Cnidaria
37/46
-
7/31/2019 Zoology Cnidaria
38/46
It is obvious as to how braincoral got its name.
-
7/31/2019 Zoology Cnidaria
39/46
Here is a young braincoral. These coloniescan build for thousands
of years.
-
7/31/2019 Zoology Cnidaria
40/46
Other organisms, such as theseChristmas Tree worms, maketheur home in or on the coral.
-
7/31/2019 Zoology Cnidaria
41/46
Corals compete for light just theway plants do on land.
This is Elkhorn Coral.
-
7/31/2019 Zoology Cnidaria
42/46
Here a damselfish hides among thebranches of fire coral. Fire coralhas tiny spines which irritate the
skin, much as a stinging nettle does.
-
7/31/2019 Zoology Cnidaria
43/46
Soft corals such asdead-mans fingers can
bend with waves andcurrents.
This is another soft coral.
-
7/31/2019 Zoology Cnidaria
44/46
Sea fans are also anthozoansalong with sea anenomes, hardcorals, tube anenomes, thorny
corals, soft corals, sea pensand sea pansies.
-
7/31/2019 Zoology Cnidaria
45/46
"Why do evolutionary biologists care who's related to whom, and how do scientists find out how different
animals are related?"
http://www.ucmp.berkeley.edu/phyla/Phyla2001.maphttp://www.ucmp.berkeley.edu/phyla/Phyla2001.maphttp://www.ucmp.berkeley.edu/phyla/Phyla2001.map -
7/31/2019 Zoology Cnidaria
46/46
Scientists care because phylogeny is the fundamental product of evolution.Therefore, a phylogenetic hypothesis is essential if you want to understandbiological phenomena, most of which have an evolutionary explanation.
Since many scientists would like to know how animal diversity and animalbody plans came to be, presently there is a great deal of work on resolvingthe evolutionary relationships among the major groups of animals. Much ofthis research has relied upon morphological characters, especially thoseexpressed in early development (e.g. embryological characters). Morerecently, a significant advance in our understanding of animal phylogeny
has been brought about by the study of molecules (in particular genes andtheir protein products) contained within animal cells. The phylogenypresented here is a relatively conservative guess based upon variouspublished studies of 18S ribosomal RNA sequence data. As you can see,there are quite a few unresolved branches, and therefore a great deal ofwork to be done in this area.
Note that the phylum Porifera (the sponges) is paraphyletic. A few lines ofindependent evidence suggest that one group of sponges is actually moreclosely related to non-sponge animals than it is to the other sponges. Thisis an important finding for it implies that the lineage leading to all otheranimals (including ourseleves!) was directly descended from an animal witha sponge body and a sponge life style.
http://evolution.berkeley.edu/evolibrary/article/evo_03http://www.ucmp.berkeley.edu/clad/clad4.htmlhttp://www.ucmp.berkeley.edu/porifera/porifera.htmlhttp://www.ucmp.berkeley.edu/glossary/gloss1phylo.htmlhttp://www.ucmp.berkeley.edu/glossary/gloss1phylo.htmlhttp://www.ucmp.berkeley.edu/porifera/porifera.htmlhttp://www.ucmp.berkeley.edu/clad/clad4.htmlhttp://www.ucmp.berkeley.edu/clad/clad4.htmlhttp://www.ucmp.berkeley.edu/clad/clad4.htmlhttp://evolution.berkeley.edu/evolibrary/article/evo_03http://evolution.berkeley.edu/evolibrary/article/evo_03http://evolution.berkeley.edu/evolibrary/article/evo_03http://evolution.berkeley.edu/evolibrary/article/evo_03http://evolution.berkeley.edu/evolibrary/article/evo_03http://evolution.berkeley.edu/evolibrary/article/evo_03http://evolution.berkeley.edu/evolibrary/article/evo_03http://evolution.berkeley.edu/evolibrary/article/evo_03http://evolution.berkeley.edu/evolibrary/article/evo_03http://evolution.berkeley.edu/evolibrary/article/evo_03http://evolution.berkeley.edu/evolibrary/article/evo_03http://evolution.berkeley.edu/evolibrary/article/evo_03http://evolution.berkeley.edu/evolibrary/article/evo_03