Transcript Sponge Defenses - Fat Tuesday Productions

Sponge Defenses
How does a sponge defend itself?
Chemical Defense
• Many sponges have
chemical defense
mechanisms that help
protect them against
certain bacteria; they
produce toxins or
unpleasant tastes and
odors that ward off
predators or prevent coral
overgrowth that could
threaten the sponge's
osculum or other systems
What are secondary metabolites?
• Secondary metabolites- are organic
compounds that are not directly involved
in the normal growth, development or
reproduction of organisms, these can be
wastes from metabolism or chemicals
produced for defense, competition or that
aid in reproductive success
What are some secondary
metabolites?
• Alkaloids- naturally occurring amine in plants
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•
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and animals
Terpenoids- lipids, largest group of natural
products made by many varied organisms
Glycosides- heavily modified sugar molecules
Other compounds-Phenols, phenazines,
polyketides,fatty acid synthase products,
non ribosomal peptides
Why do sponges use secondary
metabolites for defense?
• Sessile- animals that are
not able to move about
Ex. Sponge, hydra
• A sponge is attached to a
solid surface and is
unable to flee when faced
with a predator
Azure vase sponge
What do sponges do when
threatened?
• When threatened sponges can release
those stored secondary metabolites
that have cytotoxic, antibiotic and feeding
deterrent properties
• These chemicals prevent settlement of
fouling organisms on the sponge surface
and restrict competition for space with
neighbors
Spatial Competition
• Space on which to live is often the most
important limiting resource in marine
hard-substrate environments. Maintenance
of a given level of diversity in these
environments has been attributed to the
interacting roles of competition, predation,
and disturbance.
Spatial Competition
• Evidence shows that sponge metabolites
may act as allomones by preventing
overgrowth of some sponge species, and
as both allomones and kairomones by
enhancing overgrowth of others.
What do sponges do when
threatened?
• They can repel potential predators
• They control bacterial growth within their
bodies
• Sponges can actively defend by upon
injury, they can convert less active
precursor molecules to more active
defense chemicals to repel predators or
prevent infection of the area
Aplysina aerophoba
• This sponge from the
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Mediterranean upon
injury degrades its
defensive chemicals
and manufactures
compounds,
aeroplysinin-1 and a
dienone, with strong
antibiotic properties
prevents infection of
injured cells
Feeding deterrent
• In order for a sponge to prevent predation it
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must release chemicals that make another
organism not want to feed on it
Researchers have separated some of these
materials and added the to fish food to see the
reaction of predatory fish
By isolating and identifying these compounds
researchers have been able to utilize the
properties of the isolated compounds
Fire Sponge
• Tedania ignis, also known as fire sponge, is a
species that is readily found in Bermuda on
any type of substrate. T. ignis is an interesting
sponge because it contains toxins as a defense
mechanism to deter predators, which can be
shown as an adaptation due to the increasing
amount of predators.
Fire Sponge
• The main defenses of
fire sponge involve
chemical deterrence,
contain spongin
spicules, as well as have
refractory collagen,
which allows the sponge
to be rubbery and
discourage predators
from eating them.
Caribbean Reef Sponge
• Studies have
determined that
Caribbean reef
sponges of the genus
Agelas are chemically
defended from fish
predation by
bromated pyrrole
alkaloids.
Defense Mechanism
The defense mechanism of a fire sponge is a toxin that is expelled
through the spicules, which pierces the predator, causing a severe
rash when handled by humans, or will cause the predator
discomfort. Caribbean reef fish do not feed on Tedania ignis due
to its toxic chemical it produce. However there are some animals
that have defense mechanisms against this in which they are able
to digest the sponge toxic material for example some starfish. T.
ignis uses chemical deterrence to protect themselves against
overgrowth, or the killing of other species larvae; therefore
allowing the fire sponge to thrive.
A Starfish wins the Arms Race!
• Starfish in Bocas del
Toro Panama and Belize
have evolved a
mechanism to
breakdown the Fire
sponge toxin and
consume the entire
sponge. amount of
predators.
Questions
• What is the difference between a primary
metabolite and a secondary metabolite?
• What is the term for non motile? Name
other non motile organisms.
• How do sponges defend themselves
against predatory fish? 2 ways
• What is one possible
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way that Spongebob
can defend himself
from predators?
What if Spongebob
was to get invaded by
bacteria, how would
he defend himself?
How successful do you think this
stern warning would be against a
predator?