chartreuse/yellow sponges

[rsteagall]

I have some fairly prolific chartreuse/yellow sponges in my tank. I'm curious if these or any other kind of sponge is undesirable? The grow nearly 100% of the time under rocks in the dark. Could they be phosphate factories or anything else bad?

bad picture but this is what i found googling.

I'm pretty sure thats it.

 

[philter4]

I don't know about many sponges, as far as producing phosphate, or anything else, I have no idea, but sponges have chemical weapons with which to protect themselves from being eaten and that can potentially foul and poison other tank inhabitants. If it is growing well, it is a potential filter for the tank, a very efficient one at that, healthy sponges pump huge amounts of water through them, and by the discription of how prolific they are to remove them means what ever they are eating will be free in the tank.

 

[rsteagall]

I'm just trying to figure out if I should introduce these or anything similar to these in my new tank I'm getting ready to upgrade to.

 

[greenbean36191]

f it is growing well, it is a potential filter for the tank, a very efficient one at that, healthy sponges pump huge amounts of water through them, and by the discription of how prolific they are to remove them means what ever they are eating will be free in the tank.

They're mostly filtering and eating bacteria. That's what coral do too, so really you don't want the water devoid of bacteria. Like any other animal they also turn their food into waste (ammonia) and pee it back out. Most species really don't provide any benefit to water quality. Unless there is a whole lot of sponge biomass though the impacts of their nitrate and defensive chemicals isn't something to really worry about.

 

[philter4]

While it is true that many sponges feed mainly on bacteria, there are other sponges that feed on organic matter and even a group of crustacian predators that actually trap them inside and digest them. The usefulness also comes from the fact that they do not take most benificial bacteria, only free living bacteria such as disease causing and others that may or may not be harmful. I always thought corals were photosynthetic for most of their nutrition, feeding on the products of the zooanthelea algae in their cells.

 

[greenbean36191]

Corals can get almost all of their carbs from their zooxanthellae, but they don't get protein. For protein they have to eat. While some species feed heavily on zooplankton, almost all get a significant portion of their food from bacteria.

There are carnivorous sponges, but none of them are found on reefs. The ones we get essentially all feed on POM and bacteria and feed from the same pool as our corals. Most also farm bacteria within themselves. All of them excrete more DIN than they take in though. They don't provide any more benefit than just adding more corals.

 

[rsteagall]

So... It seems quite possibly these sponges are doing more harm than good... that is if I don't enjoy looking at them hidden under rocks. ?

One thing you mention though.... they feed off bacteria? Are you referring to bacteria in the water column? Because... I was under the impression that little bacteria actually lives in the water column itself. Especially if you have a UV filter Care to expound?

 

[greenbean36191]

Well, they're about as helpful as adding another fish. I certainly enjoy them when they show up in my tank and I try to encourage their growth, but I also realize they aren't really helping the tank.

They get bacteria from a couple of places. Most reef sponges house bacteria within their bodies and sort of farm and eat them. Corals do the same thing. Both also feed on bacteria in the water as well. When compared to the amount of bacteria growing on hard surfaces the amount in the water is extremely small. However, that doesn't mean they're not still abundant. What you typically find are clumps of bacteria piled on top of one another or around a little speck of detritus. Unless you're running an open system with a UV filter on the intake, even a UV has little impact on the amount of bacterioplankton.