Transcript Porifera - Net Start Class

Porifera
Salem Karani
Shanery Tam
Tara Templeman
Period 5
Characteristics
• come in an incredible variety of colors and an amazing
array of shapes
• predominantly marine
• Are amongst the oldest creatures, even dating back to
the Pre-Cambrian period
• Body multicellular, few tissues no organs
• Live in aquatic environments, mostly marine
• Often has skeleton of spicules
• Cells and water surround a water filled space, but no real
body cavity
• Has no nervous system
Classes
• There are four different sub groups within porifera
– Hexactinellida
• sponges with a skeleton made of four- and/or
six-pointed silaceous spicules, often referred to
as glass sponges
• some researchers consider them unusual
enough to deserve their own phylum,
Symplasma.
palaeos.com
• Glass sponges are relatively uncommon and
are mostly found at depths from 450 to 900
metres
• Example would beVenus’ flower
basket(Euplectella)
Classes (cont’d)
– Demosponge
• largest class in the phylum Porifera (includes 90%
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of sponges)
• Their skeleton are made of spicules consisting of
fibers of the protein spongin and the mineral silica
• they reproduce asexually and sexually
• There are many diverse order in this class,
including all of the large sponges
• example would be: Spongilla, Cliona
Classes (cont’d)
– Calcarea
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• Members of this subclass are unique in that their spicules are made
of calcium carbonate
• Also these spicules don’t have hollow axial canals
• Been around since Lower Cambrian period
• Diversity is greatest in the tropics
• Found mostly in the shallows
• Represent all three sponge body plans
• Many variations, but mostly drab colors. Also there are 2 subclasses
and 7 orders: Calcinea-Cathrinidia, Leucettidia, Murrayonida and
Calcaronea: Baeridia, Leucosolinida, Lithonidia, Sycettida
• Example- Sycphla Leucosolenia
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Classes (cont’d)
• Sclerospongiae
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– sponges with a soft body covered with a hard outer body made
of calcium carbonate
– Long life span of 500-1000 years
– Dense, layered skeletons similar to coral reefs
– First proposed in 1970 by Hartman and Goreau
– Not closely related
– Fossils already known from Cambrian period
– Examples:Ceratoporella nicholsoni, S. norae
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Body plan
mun.ca
Body Plan (cont’d)
• May have either radial symmetry or none at all
(asymmetrical)
• Work like chimineys-take in water from top and release
through bottom
• 3 plans- asconid (tube/vase shape), syconid (pleated
body wall) and leuconid (full of mesophyll/tubs for
controlling water flow)
• Control the water flow through their bodies through this
and open/ close the oscullum and ostia (intake pores) in
regards to currents/etc to release and intake water
Feeding
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don't have mouths
have tiny pores in their outer walls through which water is drawn
Cells in the sponge walls filter nutrients from the water
Water flowing through pores provides food and oxygen
flow is actively generated by the beating of flagella
Regulation of the amount of flow through their bodies by the
constriction of various openings
• Water drawn into central cavity (spongecoel) and flows out through
larger opening (osculum)
• Sponges of the family Cladorhizidae are unusual in that they
typically feed by capturing and digesting whole animals
Respiration
• A sponge’s excretory, circulatory and respiratory
systems are basically all nonexistent-controlled instead
by the water flow through its body
• Sponge uses its ostia pores to intake water
• Uses oscullum pores to let it out
• Sometimes has canals and such (see body plan
leuconid) to control water flow better
• Takes in oxygen through this water flow
• So has to have water to live, thus most songes are water
based
Circulation
• Sponges don’t have nervous, digestive, or circulatory
systems
• Instead they rely on the constant water flow through their
bodies to remove waste and to take in food and oxygen
• The shapes of their bodies are adapted to maximize this
water flow (see the body plans)
• Have different sources of food-mostly the bacteria or
food particles in the water that flows through them
• If there is poor food source available may turn
carnivorous for small crustaceans
• Some have a symbiotic relationship with autotrophic
microorganisms living in them
Excretion
• canals in the body which water flows
through
• water leaves the sponge through the large
pores called oscula (osculum for singular)
• The water enters the ostia, is drawn
through to the spongocoel and leaves
through a single large osculum
Response
• Lack nerves or muscles
• Individual cells sense and react to changes in the environment
• Has no nervous system/tissue although has flask cells (the parent of
nervous tissue)
• Are mostly unmoving and as such has complex body structure to
help with this.
• Mostly made of mesophyll, jelly like substance e made and
reinforced by collagen
• Covered by pinacocytes that are plate-like and help anchor it too
• Have choanocytes on interior of body that use flagella to drive water
through it
• Has myocytes (muscle cell) that helps it control its muscles
• Control the body tissues to control water,etc
• Also some special cases, such as glass sponges can transmit slight
electrical charges
Movement
• Usually or almost completely Sessile
• However marine and freshwater species can move across the
bottom at speeds of 1–4 mm per day
• This would be due to amoeba like movement of certain cells like
pinocytes
• Some species can actually contract their entire bodies
• Many can close their osculum and ostia, which are openings on the
outside of their bodies
• most are sedentary or immobile as adults
• Spend their life fixed to a substrate
Reproduction
• Reproduce sexually or asexually by releasing fragments of
themselves
• Asexual forms include fragmentation, budding, and gemmules
• most sponges are hermaphroditic
• only one gender at a time, being either male or female or neuter
• a number of areas of the sponge will change to produce either
sperm or ova (eggs)
• Sperm is released into the canals and pumped out of sponge
through osculum where it is likely to be drawn into canal system of
another sponge
• incoming sperm of same species are trapped by choanocytes which
then migrate to the ovocyte, a cell generating ova, where sperm are
transferred to ova
Works Cited
• Lawrence. (2006, May 4). Animal Body Plans. Retrieved
from
http://userwww.sfsu.edu/~efc/classes/biol170/AnimalBod
yPlans-lecture41.pdf
• Irwin. (2007, June 17). Porifera: Life History and
Ecology Retrieved from
http://www.ucmp.berkeley.edu/porifera/poriferalh.html
• Ramel. (2003, August 17). The Phylum porifera.
Retrieved from
http://www.earthlife.net/inverts/porifera.html