Threats to Marine Species

Invertebrate: Nudibranch, Triton, and Daidema

Jan 31, 2013

Nudibranch

• soft-bodied mollusk

• 2 - 60 cm long• live in the coral

reef• Pretty but ... toxic

What is it? ...

NUDIBRANCH ALiEN?Cartoon?

• Bright-colored nudibranchs send signals that they taste nasty, but some species try to protect themselves by using camouflage colors.

• Some species wear their gills on their back, and when frightened, they pull their gills into special pockets on their back.

• 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

• 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...

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.

They are indicators because their presence in a habitat and their general health indicate the health of the surrounding environment.

SO WHAT??

Tourists & taken as Pets

Not a big concern

• Short lifespan • Early reproductive age

Big Threats

Triton(Charonia tritonis)

• 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?

• 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.

• 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?

• 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?

DIADEMA

• 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?

• 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?

• 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?

http://en.wikipedia.org/wiki/Diadema_antillarum

http://en.wikipedia.org/wiki/Charonia_tritonishttps://www.google.co.uk/search?hl=en&sugexp=les%3B&gs_rn=1&gs_ri=hp&tok=LPtyHeUTeOH3_-

MmqAk7Hw&cp=14&gs_id=2&xhr=t&q=trumpet+triton&bav=on.2,or.r_gc.r_pw.r_cp.r_qf.&bvm=bv.1357700187,d.aGc&biw=1366&bih=677&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi&ei=ZM_zUJGPK8zhlAXbyoCgBA#um=1&hl=en&tbo=d&tbm=isch&sa=1&q=trumpet+triton+&oq=trumpet+triton+&gs_l=img.3...5685.5685.4.5844.1.1.0.0.0.0.47.47.1.1.0...0.0...1c.1.w1XmqHlQZR8&bav=on.2,or.r_gc.r_pw.r_cp.r_qf.&bvm=bv.1357700187,d.dGI&fp=557f26b889bc7da7&biw=1366&bih=677

http://flickrhivemind.net/Tags/charoniatritonis/Recenthttp://www.malawicichlidhomepage.com/aquainfo/charonia_tritonis.htmlhttp://eol.org/pages/403845/detailshttp://www.thecephalopodpage.org/marineinvertebratezoology/diademaantillarum.htmlhttp://

www.thecephalopodpage.org/marineinvertebratezoology/diademaantillarum.html

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