The benefits of detritus.

[Paul B]

I know, stupid title but I didn't know what else to call it.
I just had to move a piece of coral in my tank and by doing so I had to stir up the gravel. (yes I have gravel) When I do that there is a slight dust or detritus storm which I know benefits the corals. As I was looking at the tank I noticed something that newer tanks may not experience. I forget about these things because I always see them and I figure they are normal but I figured I would post it anyway.
In my tank there are dozens of these small coiled up worms that have become part of the rockwork and can not be removed. (I think these are sponge worms, but don't quote me) I pay little attention to them and never see them do anything, but when I stir the gravel, the tank becomes encased in "spider webs" of sticky threads that are exuded from these tiny organisms. In 5 minutes, when the tank clears up and the storm dissapates all that is left is these 10" long strands that are slowly pulled into the animal where the meal is digested.
Normally the water is crystal clear and you can see nothing emerging from these worms.
These unassuming animals are one reason I am not a fan of a sterile tank.
Many animals that we really don't see or don't pay any attention to feed in this manner. If it were not for detritus, these worms and many corals, clams and microscope life would not exist. Some of these animals are at the bottom of the food chain and a healthy eco system depends on them.
I think most of us hobbiests are much more interested in the easier to see things like fish but I find the unusual parts of the hobby to be much more interesting.

 

[Gary Majchrzak]

looks like a Vermitid from here, Paul.

These animals can proliferate in "clean" Acropora dominated aquariums, too.

here is a thread with pictures showing how an Acropora entombed one of these snails.

 

[Paul B]

looks like a Vermitid from here, Paul.

It could be but I would have to look it up to be sure. I am not real interested in it's exact name but I find all of these things facinating. I have a horrible memory for names, I was married for 6 years before I remembered my wife, Whats her name?

 

[Gary Majchrzak]

I know what you're saying

I know what you're saying

I'm also fascinated by many things that I'm not real interested in finding out their real name

 

[Mike31154]

I end up stirring/vacuuming the sand a bit when I do water changes in my sumpless system and also see the nasty detritus dust cloud. Although you're not that interested in the exact name of the creature in your photo, I think I had one years ago when my tank was just set up. Curiosity go the better of me & I did some searching to find out what it might be. Look up 'terebellid'. I bought the system used so there were plenty of strange creatures in the rockwork. My terebellid got taken out by a Copperband Butterfly though.

 

[Paul B]

Look up 'terebellid'

Yes, and a sponge worm is one of those.
It looks just like this

http://www.scuba-equipment-usa.com/marine/JUN06/Sponge_Worm(Loimia_ingens).html

 

[ReefTeacher]

whatever they are I have a ton of them in my display and the sump. My tank is only 4 years old, although I have some rock in there that is twice that old from another system. I noticed that some butterflies will pick at the threads if they are full of detritus. I do love all of the unknows that come in with live rock!

 

[SushiGirl]

They're vermetid snails.
Hitchhikers are awesome!

 

[Paul B]

They're vermetid snails.

Could be, but there are hundreds of types of vermetid worms and snails not just the snails we call most of them.

 

[Gary Majchrzak]

Perhaps we should discuss the benefits of LIMITING detritus in a reef aquarium

Fortunately or unfortunately, I got involved in this thread early on.

Perhaps we need to define detritus?

In any case, the limitation and removal of mulm, detritus, wastes (etc.) is a good thing for most reef aquariums. Of course, there are some reefkeepers that prefer to keep critters that thrive in environments of mulm and detritus.
This isn't a slam on anyone- I used to keep an aquarium for these types of critters myself!
I think we should point out:
*you can have Vermitids and Terebellids in a well maintained "clean" reef aquarium
*the absence of detritus (alone) certainly doesn't make an aquarium "sterile"
*a sterile (low biodiversity) reef aquarium should be avoided IME/IMO (and Paul's)

It's my personal experience and opinion that a greater biodiversity of reef critters can be maintained in an aquarium that controls and limits detritus.

I'm a big fan of biodiversity. Whatever one calls their critters.... they are interesting.

Now... onto another observation. (We ARE in the Advanced Topics Forum after all!)

Why did your Vermitid attach itself in that spot?
They usually settle and attach on reef structures near the surface in an area of decent water flow.

Do you still run your UG filter at all?

 

[muttley000]

Sometimes when I feed rods food it will get stuck on these and I remember they are there. I agree the best part is the things I'm probably the only one that notices!

 

[Paul B]

Why did your Vermitid attach itself in that spot?
They usually settle and attach on reef structures near the surface in an area of decent water flow.

Do you still run your UG filter at all?

I have a dozen or so vermitids that I can see, they have always been in my tank. The tank has always had a RUGF. The first couple of years it was a regular UG filter but then for the last 35 years or so I ran it very slow in reverse.
I never advocated trying to acumulate detritus in a reef aquarium but if your tank is old enough and healthy enough there will be boreing organisms that produce the stuff in copious amounts. If I were to blow water at my rock I would get a large amount of detritus emitting from the pores. This is inevidable as the microscope life in the tank produces it.
You will not see any detritus in my tank but if I move a rock or stir up the gravel as in that first picture, I will see it. Detritus is the end product of de composition and IMO will not harm anything but can and will benefit the amphipods, copepods and detritus feeding corals that predominate in my particular tank.
I am also not saying to keep a filthy tank, just the opposite. I add bacteria from the sea all the time in an effort to maintain an equilebrium of nutrients and I succeed by hardly having any nitrates and doing few water changes.
I also did not mean that you should actively cultivate vermitid worms, but their presence and the presence of other forms of life should not be considered a detriment to the tank but a sign of health.

 

[Agu]

... but their presence and the presence of other forms of life should not be considered a detriment to the tank but a sign of health.

I have to agree. Although my nano tanks aren't as old as your tank Paul (6-8 years old), I'm seeing the result of not adding diversity to my tanks. Almost nothing new has been added for several years and I can see the decline in biodiversity. Used to have a bunch of spaghetti worms but they slowly died off, I can see the negative effect on the sandbed. With limited space just adding live rock/ live sand isn't a great option. Rather I'm planning to make changes that involve replacing some of the existing rock/sand with aquacultured just to reintroduce some more biological diversity.

 

[reefmanmatt]

benefits of detritus : well lets see... for me it would be i could ignore my begging fish easier when the glass was dirty cool vermetid pics , i had one of these with my first piece of coral a very long time ago . we called him oscar the grouch ( theyre easier to remember when thats all you have , and free was just awesome at the time )

 

[klepto]

I also did not mean that you should actively cultivate vermitid worms, but their presence and the presence of other forms of life should not be considered a detriment to the tank but a sign of health.

While vermetids may be a sign of 'health' in relation to biodiversity- In my experience these snails rarely offer any benefits to reef systems.

Most of the species I am familiar with typically reproduce very fast. They regularly build up inside of powerheads and if they aren't removed can compromise the efficiency and life of the device.

Additionally, as evident in your image, vermetids are capable of extending a feeding mucus which can smother coral polyps. Acropora seem to be more sensitive to the mucus than other genera of corals that I am familiar with. I have witnessed tissue recession and growth inhibition in localized areas to the regular extension of such feeding mucus.

While the impact of the feeding mucus may not be overly detrimental, I actively remove vermetids from my tank- especially those nearby corals. I also don't like how the mucus effects aesthetics.

 

[ChrisKirkland]

I use to take a spare power head and stir the sand with my hand and blow the detritus around just before the lights went off to feed my corals and other critters. When I had my bare bottom tank I would blow off the rocks and the bottom of the tank to stir it up and would sit and watch the corals open up to feed.

 

[Paul B]

Well if nothing else, it is an interesting topic. :wavehand:

 

[EnderG60]

I have those all over my tank as well. The little ones seriously suck when moving rocks around, they are like little hypodermic needles!

But yeah, mine do that every time I feed as well.

Oddly enough I only get them in the display, while I have millions of feather dusters in the fuge and none in the display. Yet both basically do the same thing.

 

[herring_fish]

I have these worms in my tank as well. I am a person that feeds a lot. I re-started my tank after relocating and a long respite with dead rock. For the first several months, I had a lot of detritus that was visible around the tank. It has been running for about two and a half years and the detritus as diminish quite a bit.

Now for another subjective observation. In my old tank, I had a Jaubert sand bed. For those that are not familiar with the popularized version that I am talking about, I will describe it. I had a plenum or open water space of about an inch on the bottom of the tank. A layer of screen with 3 inches of coral gravel was on top of that. Another screen was on top of the gravel, with 4 more inches of coral sand on top of that. I lowered the front so that it looked better against the front glass. Critters are suppose to inhabit the top, aerobic zone but nothing gets passed the two screens into the stagnant anaerobic zone.

I wanted to see into the plenum so before I installed anything, I encased a plasticized magnet in epoxy and placed it on the bottom piece of glass in the tank. The stand that I had, allowed me to look up through the bottom of the tank. In about a month a layer of detritus formed on the bottom glass. In a few months, I put another magnet up to the first one and was able to slowly and carefully drag it around through the sediment. I could see that it was very uniform at about 1/4 inch thick. I only did this one or two more times over 8 years or so. It wasn't too exciting.

When I tore the tank down, I was careful when I got to the sand bed. I looked at the bottom sediment and there was that same 1/4 inch of detritus that formed in the first few months.

It appeared to me that something processed this stuff. The screens are there to keep out critters and there weren't any dead skeletons, shells or any other forms of remains. What ever it was, it must have been bacterial.

Am I way off base?

 

[Paul B]

I can also see through the bottom of my tank because there is a UG filter under the gravel. The UG filter has not been disturbed in maybe 10 or 15 years and there is also a layer of detritus but it is not very think. Closer to 1/8". I can tell that because I can see worm trails all over it and I can see through it near the tubes that push water down under the UG filter so I also feel that there must be something processing the detritus or by now I am sure it would have filled up al of the available space under the filter.

Again, I am not saying that we should try to accumulate detritus, but the detritus that is there is a food source for many animals.