3. • soft-bodied mollusk
• 2 - 60 cm long
• live in the coral reef
• Pretty but ... toxic
What is it? ...
4.
5. • Bright-colored nudibranchs send signals
that they taste nasty, but some species
try to protect themselves by using
camouflage colors.
6. • Some species wear their gills on their
back, and when frightened, they pull
their gills into special pockets on their
back.
7. • Dorid nudibranchs breathe through gills
that are on their posterior. Eolid
nudibranchs have finger-like appendages
that cover their back.
• Move on a flat, broad muscle called a
foot, which leaves a slimy trail.
What you didn't know about
Nudibranchs
8. • Favorite food: They are carnivorous -
their prey includes sponges, coral,
anemones, hydroids, barnacles, fish
eggs, sea slugs, and other nudibranchs
• Male or Female? Nudibranchs are
hermaphrodites - they have reproductive
organs of both sexes
• They can photosythesis
ASIDE FROM BEING CUTE...
9. Important ecological function, playing an
important role in marine food chains,
both as predator and prey.
• Keeping the water conditions
favorable for other sea animals and
plants.
10. They are indicators because their presence
in a habitat and their general health
indicate the health of the
surrounding environment.
SO WHAT??
11. Tourists & taken as Pets
Not a big concern
• Short lifespan
• Early reproductive age
Big Threats
13. • Is a species of a very large sea snail.
• It is a marine gastropod mollusc in the
family Ranellidae.
• Found throughout the Indo-Pacific Ocean
What is a Charonia Tritonis?
14. • Can grow up to 2 feet long.
• Although the shell looks beautiful it is also used for protection against
predators.
• The giant triton looks harmless but it is also a predator, it uses its teeth
to inject its prey with a poison and stuns or paralyzes them
• In tropical waters it is the only animal able to kill and eat the "Crown of
Thorn" sea star.
• Often known as the Triton's trumpet
What is the most interesting
thing about them?
Giant triton
attacking a
crown of thorn
starfish.
15. • Reknown for being used as souvenirs they need to
be monitored.
• It is a well known predator of the crown-of-thorns
starfish (Acanthaster planci).Many species of starfish
are known to outbreak in different parts of the world.the
giant triton might have controlled starfish numbers not
by eating the many, but by preventing the aggregation
that precedes the outbreak.
Why is it on the indicator
species list in Hong Kong?
16. • In many parts of the third world, it is still being collected
in large numbers and sold to tourists as ornaments. As
you admire the beautiful shell, spare a thought for the
hungry mollusk that died. This species is actually
endangered now.
What is a threat to them?
19. • Family of sea urchin- a lot of subspicies
• long spines (d. up to 50 cm)
• slow movement
• found in shallow water (-400m)
• habitat -West Indian region- Florida-
Surinami
• often found in coral reef ecosystem
• Can cause painful wounds
What are they?
20. • Related to starfish.
• Usually black but can sometimes be
white in color.
• Central mouth on the underside and a
central anus on the upperside.
• Life expectancy: 5 years.
• Very sensitive to light
• Mostly eat algae, but starving diademas
can turn carnivorous.
What is most interesting thing
about them?
21. • Diademas are herbivorous, consuming
mainly algae,detritus and sediments
• The population density of diademas is
affected by the density of its nutriment:
algae
• Algae affects negatively coral growth
and recruitment
Why are they an indicator
species?
Increases in pollution in coastal areas have led to more dissolved nutrients entering waters close to coral reefs. The result is excessive algal growth, which may kill hard and soft corals. Too much algae means that the light conditions in the reef are unfavorable and as a result fewer corals.
Not a big concern tho...
Most gastropods have a shell and a muscular foot they use to move around.
reputation because of its devastating impact on coral reef ecosystems
In order for their eggs to be fertilized, male and female Diadema must release their eggs and sperm into the water at the same time (Simon 1973). To make sure this happens, the male or female sea urchin sends a chemical substance into the water, and the smell of this substance makes every sea urchin in the vicinity release its eggs or sperm (Simon 1973). This mass release increases the chance that the eggs will be fertilized (Simon 1973).
and will often pick its resting place depending on the shade
