Another Skirmish In the Ongoing War


We marine aquarists are in a hobby that has advanced so much over the years. Our aquariums now hold livestock that yesteryear’s aquarist couldn’t even dream about. Some of the fish we keep were deemed exceptionally difficult or impossible to maintain, and as for corals, well, no chance of any of those.

Our aquarium success is because of high quality seawater and, with a reef, lighting. The habitat isn’t dead white corals and sand anymore, it is often live rock and what could be called living sand, as in a deep sand bed, with all manner of tiny life forms in and on it.

However, not everything is rosy. As with gardeners we now have to contend with ‘weeds’. Pesky things they are, poking their heads up just to let the aquarist know they’re there. Maybe it is the high quality of our aquariums that has contributed to the weed invasion, and most likely has a lot to do with the use of live rock.

So what are these weeds? They must, I’m certain, face predation on the wild reefs as there is always something that eats something else. Unfortunately these predators are not present with the captive reef, or not usually anyway.

The first aquarium weed and probably the most common in the hobby is Aiptasia, the glass anemone. These pop up and many a beginner has been pleased as a new life form has appeared on the reef. Not so great though, as left alone they can spread tremendously and become a real problem. There are alleged predators that could be used in the aquarium. I say ‘alleged’ because there are conflicting opinions born from experience as to their effectiveness. They can also be attacked chemically.

The second weed that concerns me is the commonly called Sailor’s Eyeballs, or Bubble Algae, properly called Ventricaria ventricosa. These are small round green balls that can grow singularly or more likely in groups. Their claim to fame is that they are reported to be the largest single celled organism in existence. Again at first they seem welcome as they are decorative. They are reported to do better in high quality seawater. However, left alone they can spread alarmingly and be an absolute nuisance. I have no idea what could predate on them, apart from the aquarist. They eventually burst and release high numbers of spores to populate other areas of the aquarium. Possibly some spores are captured by polyps in a reef aquarium, but if so many must successfully locate themselves.

Quite often when I carry out maintenance I note the presence of one or the other of these weeds, or occasionally both. I never manage to eradicate either, this must be just about impossible with a highly stocked reef and rocks that provide crevices and caves and other areas that are out of the aquarist’s view.

For a long time I have been battling the blighters. They aren’t a problem as they are not allowed to be, but if I neglected to deal with them for a length of time they’d have a party.

The Sailor’s Eyeballs if burst as said release spores, so I don’t want that thank you. I use a piece of rigid airline about 10 inches long, attached to a flexible airline. After starting a siphon, the eyeballs are burst one by one, any spores of course being drawn into the siphon. It works well and considerable speed can be achieved with a little experience. I don’t want to sound weird, but it can even be quite pleasurable bursting them, a bit like bursting the bubbles in bubble-wrap. Maybe I’m just strange!

Aiptasia anemones are attacked in a different way. I don’t use any of the alleged natural predators, though one of them, the Copper Band Butterfly (Chelmon rostratus) is my favourite fish. I use a chemical concoction produced commercially and applied with a dropper. It’s very easy. A small squirt of the stuff on an Aiptasia causes an immediate reaction and destroys the anemone. There is a drawback though, isn’t there always? No, it isn’t the fact that a chemical is going into the seawater; this has never had any detrimental effect, even in a minor way, on any of my livestock, corals, fish or whatever. The problem is one that I wasn’t aware of until I read the information on the internet. I am unable to state if it is supported by science. Apparently, the Aiptasia ‘know’ when they are under attack and take protective action. They are destroyed as said, but before oblivion they release spores into the seawater, a sort of emergency response. If this is correct, the act of destroying them produces a chance of a good few more. Thumbs up, just what I had hoped for, I don’t think!

Whatever, the weeds aren’t allowed to advance too far before their numbers are reduced. I must say sometimes I get irritated with the little monsters. However, they are part of the wild reef and Mother Nature’s great design, so who am I to complain?

  1. So, what is this chemical concoction produced commercially and applied with a dropper to kill Aiptasia anemones?

  2. Its sold under the name Joe’s Juice.

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