Little Creepy Crawlies
for the week of 12/9/99
Occassionally an aquarist will become alarmed to notice what appears to be an infestation of hundreds of tiny "critters" swarming in a tank. Especially common in freshwater tanks are 1/4" long, thread-thin "worms" that can be seen cruising along the glass and wriggling through the water. Saltwater reef tanks often produce bumper crops of pinhead-or-smaller sized "bugs" that congregate in a corner or near a piece of live rock.
What are they? You've got me... while we've seen them many times over the years, I've never known of anyone who went to the trouble of tracking down genus and sspecies for any of them.
Where do they come from? There are probably a few in every aquarium, that perhaps arrived with fish or plants. It's only under unusual circumstances that they become noticeable, much less a nuisance.
What unusual circumstances? An outbreak generally requires two things to occur. First, there has to be adequate food (in the form of excess fish food or decaying plants or bits of live rock) to nourish the critter colony. Second, there have to be few fish of the size and type that might eat the critters. Outbreaks are most commonly seen in tanks of tiny fry which are too small to consume them, or of large carnivore that are too big to be interested in them.
Are they dangerous? Assuming they are not attaching to the fish, probably not - at least not directly. In fact, they may actually contribute to fish health by decomposing waste that might otherwise break down into more dangerous substances. They may indicate an unhealthy chemical condition in the tank, however.
How can the be eliminated? The simplest solution is to add fish of appropriate size to eat them, and to eliminate whatever (excess food or decaying matter) they are feeding on.
"Tip of the week" appeared regularly in 1999 and 2000.
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