Was wondering if anyone out there considers themselves a "sponge expert":rotfl: I recently acquired a blue sponge with a hairy mushroom attached. Much of the research on line claims that they need bright light :blah: - but I always thought sponges were not photosynthetic - rather relying on flagellae to assist in the movent of water through their structures. I know they need some current, and should not be exposed to air, but am mystified about the lighting requirement. :doh: I'll post pics later on.....:pic: :up: Thanks!

Well, I'm certainly no expert but here's what I know:

Not all blue or purple sponges have high light requirements. The species that do are the ones with a strong symbiotic relationship with a type of cyanobacteria, and they are usually purple or blue -- actually there are green sponges that use zooxanthellae, just like corals -- but it would help to know the species of the sponge (if possible) and where it was collected from (and at what depth).

One general rule of thumb I've heard is "if you start to see algae growing or being expelled from your sponge, move it somewhere with more light.".

here is a photo for reference - thanks for the help!

Color and morphology-wise it looks very similar to a few we have in our tank, which I think might be some sort of Haliclona sp. but I'm not 100% sure. I few months ago I spent the better part of an evening reading up on sponge taxonomy to figure out what they were and in the end I decided that life was too short and simply took a guess based on a few Google Image searches. :)

Ours tend to be a more saturated blue color when they get light, but one that doesn't get much light is still growing quite well. I'd just place it somewhere low in the tank in an area with good turbulent flow (not linear/directed flow) to start with and keep an eye on it for a few weeks. If you have any sand-sifting fish like a goby make sure it doesn't get sand all over the sponge and suffocate it.

I have noticed some die back on the sponge. We (myself and the LFS were careful not to expose the sponge to air though. Can I trim off the dying areas or should I let it be. Also, there did seem to have some algae growth on the sponge, so I have moved it to a loweer light area of the tank. Any advice or theories are welcome. Thanks!

I have noticed some die back on the sponge. We (myself and the LFS were careful not to expose the sponge to air though. Can I trim off the dying areas or should I let it be. Also, there did seem to have some algae growth on the sponge, so I have moved it to a loweer light area of the tank. Any advice or theories are welcome. Thanks!

This sounds familiar... cuz it happened to me in June ;)

Regarding "die back on the sponge", I'd take a few pictures of it everyday for a while so you can see if it is actually shrinking; a digital camera is almost as priceless as a good turkey baster in this hobby! If it is noticeably shrinking I'd pull it out of the tank (safely, no air pockets, etc..) and drop it in a quarantine tank/bucket with a powerhead and small PC light and see if it can be revived. Leaving a dead or dying sponge in your display tank can make for a nasty toxic soup.

You could try trimming the tissue if you're positive that it's dead and not just clogged up with detritus (but if it's dead, the rest may soon follow so, again, I'd pull it out and toss it in QT). I've also found ours to be easier to break than cut or trim (thus we now have 3 or 4!). In any case, I think these sponges usually experience tissue death from the inside out, not the other way around (it'll look like its "deflating"). I've used a long, very soft, feline toothbrush to dust off the sponges in our tank when they've look dirty, works like a charm and doesn't damage the sponge.

As far as algae growing on the sponge, I wouldn't move it just yet, leave it at the same level in the tank as before but increase your water flow instead. They can really lose a lot of color at lower levels and begin to look dangerously pale at the bottom of our 29G (18" deep, 130W PC lighting). I've found that more flow also helps with the detritus/clogging problem and increases the growth rate phenomenally.

Keep in mind that I'm basing this on a mere 5 months of experience with regards to Haliclona sp. so I'm certainly no expert. so far our sponges seem to be doing fine and growing but "Your Mileage May Vary!" :)

Hey... Doc T.. you rock!

Sound advice and very well spoken!

Dave

Well, the sponge is not faring too well unfortunately. The die back has continued - where the "necrotic" area turns a ghostly white. I have cut it way back in an effort to get to good sustainable tissue. I am doing this for two reasons: 1) to prevent the dying tissue from compromising any good tissue that may be left and 2) to prevent overall tank pollution.raining

As a side note, the LFS had two of these sponges - I bought the one with the Ricordea mushroom on it figuring that if the sponge had been compromised, at least I had something for my money! Anyway, THAT sponge is fairing no better - so the shipment was probably compromised coming from the wholesaler to begin with.:eek:

I'll try to keep you posted regarding how the sponge does - hopefully I have some tissue left that hasn't been compromised - but if not, I still have the Ricordea! Thanks!:up:

As a side note, the LFS had two of these sponges - I bought the one with the Ricordea mushroom on it figuring that if the sponge had been compromised, at least I had something for my money! Anyway, THAT sponge is fairing no better - so the shipment was probably compromised coming from the wholesaler to begin with

Quite possible, they can be quite hardy when they stay put, but they certainly don't have a reputation for transporting very well. When a few chunks broke off of one of ours during some aquascaping I was able to revive them in a little 5g Rubbermaid with a maxijet 600, a 27W 6500K PC bulb and daily 1g water changes using old change-out water from our main tank (too "dirty" for the corals but perfect for sponges); After 3 weeks they had all taken hold of the little rocks I had netted them too and I put them back in the main tank where they've been doing fine ever since.

Another bit of info that I figured was best to post in this thread for the benefit of anyone who might be searching the site for sponge info in the future:

If you use a hang-on-back or in-tank protein skimmer produces a lot of microbubbles you should really consider installing a sump and moving the skimmer there. While most shallow water sponges can handle a bit of air clinging to them the constant accumulation of bubbles from a skimmer will eventually reek havoc on them --- and on the rest of your tank when the sponge starts decomposing. If you can't move the skimmer you'll need to make an effort to arrange your powerheads and rockwork to keep as many bubbles away from your sponge as possible.

PS. Boz, toss that sponge (and the rock it's on) into a bucket or rubbermaid with a small PC "daylight" bulb and a powerhead, I'll bet it can still be saved.