FishChannel Forums / Saltwater Forums / For Reefkeepers / question for critical thinking class / Latest Posts

RE: question for critical thinking class

Nep2Ns PlumR — Thu, 17 Apr 2008 04:36:14 GMT

Cool!

RE: question for critical thinking class

MoorishIdol — Wed, 16 Apr 2008 05:53:12 GMT

i just wanted to thank you all for your help! because of my research on this website, i got a b or an a i think (i forgot lol) but i gave a good scientific answer and it didnt sound like other peoples- they sounded like they just copied and pasted it from the internet. but i am proud of my poject and i just wanted to thank all of the knownledgeable fishkeepers that helped me find this information.

RE: question for critical thinking class

deluxerider — Sat, 29 Mar 2008 07:42:15 GMT

I agree! That's a complete answer. It made me laugh, it made me cry, it had a good beat to dance by. I'd give it a "10"

Hail the weasel!!!!

RE: question for critical thinking class

Nep2Ns PlumR — Thu, 27 Mar 2008 04:38:03 GMT

Now that's what I'd call a complete answer. I bet Jeremy got a good grade in his critical thinking class!

RE: question for critical thinking class

FishChannel Moderator — Wed, 26 Mar 2008 11:48:56 GMT

It may be a little late, but we asked our FishChannel "Below the Surface" columnist Jeremy Gosnell to answer this question for an upcoming installment of his column. We found this to be a good question that would add to the FishChannel content. The article won't be up on FishChannel for a while, but you can check out his response now. He has allowed us to post this here for you, prior to the article coming out.
--F.M.

Why is there scum and mold on reefs and sea rocks? I know Moorish Idols and other fish eat it, but I need some answers?

-FishChannel Message Boards, posted by Moorish Idol

There are a variety of living organisms that are encrusted on reef rock or what we aquarists commonly refer to as live rock. Live rock isn’t actually alive but is called live rock because of the many living organisms that make it home. Some of these creatures are miniature invertebrates and crustaceans like copepods and amphipods while others are larger animals like small porcelain crabs and even shrimp. Though the scum you refer to is likely the biological slime that compiles as bacteria colonies form over the rock.

Bacteria can form an encrusting slime; in fact they even form this slime on aquarium gravel and glass in freshwater aquariums. It is this “bio-slime” that helps filter our aquarium water and natural reef water. These bacteria are responsible for the conversion of ammonia to nitrite and nitrite to nitrate so they play a very important role both in the aquarium and on the natural coral reef. The mold you describe could be a variety of living things.

It could be a clear or yellowish encrusting sponge that is not uncommon. Also, blue encrusting sponge can grow over coral reef rock and add a certain amount of flair or color. Macro algae like Chaetamorpha could be growing on the rocks, though this would create long plant like strands, not really as a mold. Nuisance hair algae are often found growing in the aquarium and on the reef and many times resemble (both in appearance and texture) human hair. These algae can be green, black or brown in color and are often difficult to eradicate.

Encrusting coralline algae is often found on reef rock and appears as bright pink spots or dark maroon red areas. Coralline algae, unlike other algae utilizes calcium in the water and absorbs the blue spectrum of light not red and orange like many common algae species. For this reason coralline alga is often found deep down in the reef drop off zone since red and orange spectrums of light are absorbed much quicker than blue. Also coralline algae are common in shallow reef zones like the reef crest. In these areas low depth and high wave action make it impossible for corals to survive. The durable coralline algae can encrust there without any competition for space from corals. This algae acts like a sort of biological cement and helps protect the reef and corals from the destructive power of heavy wave action.

Turf algae is a common term for the collective species of algae that are found growing on live rock. If you look closely at any piece of live rock you will often see tiny strands of various sizes, shapes and colors growing off the rock. That would represent turf algae and what you are seeing may be a dozen or more individual algae species all competing for the same space.

Algae are a food source for many varieties of reef fish. Surgeonfish are perhaps the most infamous algae grazers and the Pacific Convict Tang Acanthurus triostegus is a highly vital species in maintaining areas of high algae growth on South Pacific Reefs. In addition to surgeonfish many species of Blennies, Gobies, Damselfish, and as you mentioned Moorish Idols feed upon algae. The Dusky Damselfish Stegastes dorsopunicans (common on Caribbean coral reefs) actually farms a small algae patch. Females select males that have the most abundant and productive algae patch. In the world of scientific diving we say the Dusky Damselfish impresses a female with an algae patch much like a human would an expensive sports car. Algae also work as a good food source for many invertebrates. Snails, sea urchins, and many varieties of crabs all rely on algae for sustenance. It is even a great nursery for juvenile fish.

Algae, sponge, bio-slime, and coralline algae are all common organisms on basically any natural or captive piece of live rock. These species all form a unique and important part of the food chain or serve a purpose that often times helps protect a coral reef and keeps things functioning normally. With the help of animals like Surgeonfish and Sea Urchins algae growth is kept in check and coral reefs remain healthy. Years ago a rare virus wiped out 90 percent of all Long spine Sea Urchins Diadema antillarum in the Caribbean Sea. Turf algae nearly decimated the entire reef eco-system, so you can quickly see how each animal plays an important ecological role.

--Jeremy Gosnell

RE: question for critical thinking class

Nep2Ns PlumR — Tue, 25 Mar 2008 10:03:22 GMT

I'd say you followed instructions perfectly!!!!

RE: question for critical thinking class

MoorishIdol — Tue, 25 Mar 2008 08:48:57 GMT

well, she assigned us to do this project, and research the answer on the internet. it is an assignment for writing a myth and then finding the real answer. it deosnt matter how you find it on the internet, but you just have to find it, as long as you dont like cheat or whatever, so all i am asking is for you alls input. :|

RE: question for critical thinking class

Hailey — Tue, 25 Mar 2008 05:31:37 GMT

LOL!

RE: question for critical thinking class

Nep2Ns PlumR — Tue, 25 Mar 2008 04:54:13 GMT

Heeeeey.......I resemble that remark!!!!!!!!! Lets here it for the weasels, we-zel we-zel we-zel. Besides critical thinking wastes time you could be spending working on/enjoying your aquarium.

RE: question for critical thinking class

Hailey — Mon, 24 Mar 2008 14:21:04 GMT

Ummm...if this is a "critical thinking" class, shouldn't you be...I don't know...thinking critically about it instead of asking us? I don't mean that to be rude. It's just that my husband is a high school teacher so I think this way...I have seen a lot of students trying to weasel out of assignments.

RE: question for critical thinking class

MoorishIdol — Mon, 24 Mar 2008 12:09:48 GMT

thank you so much! that is EXACTLY what i was looking for! as for anyone else, feel free to add to it!

RE: question for critical thinking class

Nep2Ns PlumR — Mon, 24 Mar 2008 09:31:29 GMT

.........?!?..........I guess under the right (or wrong) conditions there's scum/mold on everything. Undesireable algaes in a salt water aquarium are usually due to excesses in the water column of one sort or another. Bluegreen algaes (cyanobacteria) are usually due to phosphates and/or nitrate levels where as diatoms are usually due to high levels of silicates.

Not really sure if that answer's your question.

question for critical thinking class

MoorishIdol — Mon, 24 Mar 2008 08:56:39 GMT

i need this answered ASAP, because this is due pretty soon. Why is there scum and mold on reefs and sea rocks? i know moorish idols and other fish eat it, but i need some answers!!!