Of Shrimp and Snails A series by "The Under gravel Reporter"
in -"spite, /of Xjiopui^f^
here is at least one frequent contributor to this magazine who is a staunch advocate of snails. His reasoning seems to be that snails are part of the ecosystems in nature and, since we are trying to duplicate somewhat nature in our aquariums, snails should be a part of it. While this aquarist is extremely skilled (admittedly far more than I), and I otherwise respect and follow his advice, I simply don't like snails in my tank. This aquarist probably truly believes what he says. But, coming from anyone else, it would sound like the gardener who has a field of weeds, and who argues that he intended to cultivate weeds because, hey, weeds are part of the natural ecosystem. While some "snail advocates" say that snails are a sign of a healthy tank, I take the position that if the snails can find enough to survive in my tank, I'm either overfeeding my fish, or under-cleaning the tank. Nonetheless, there are snails in some of my tanks, despite my best efforts to keep them out. I will not put plants from my "contaminated" tanks (that is, my tanks that have snails) into an "uncontaminated" tank. I take care to not use a net in an uncontaminated tank if it was just used in a contaminated tank. While, up to now, I have been able to keep my tank contamination level stable, I have been upset that I allowed it to spread to more than one tank after I first discovered it. If this has happened to you, you should know you are not alone. A CNN report on January 5, 2001 titled "Killer Shrimp Stalks Waterways of California Aquarium" stated: "The SplashZone, a normally tranquil children's section at the Monterey Bay Aquarium, has become the scene of underwater carnage at the claws of a killer shrimp."
T
Modern Aquarium - Greater City A.S. (NY)
"Prized sea snails, barnacles and hermit crabs have been reduced to piles of broken shells by the lightning-quick claws of a single mantis shrimp — a voracious, salt-water scourge that for months has eluded captors and reduced a coral reef exhibit to a killing field." It seems that mantis shrimp, which are known for their fast and powerful claws (and have been called "thumb-splitters" for their ability to do just that to an unwary skin diver or aquarist), invaded the 1,300-gallon tank last April, probably hidden in a shipment of rocks from Florida. The way I see it, the Monterey Bay Aquarium is facing the same problems with mantis shrimp that I am facing with snails. The Monterey Bay Aquarium could introduce shrimp-eating fish, but they are concerned that such fish would also eat the hermit crabs and snails that are part of the exhibit. (Yes, they want snails in their exhibit, and if my tank were 1,300 gallons, I might not mind a snail or two, either.) For my part, I could introduce Clown Loaches, but clown loaches are not compatible with the water parameters in some of my "contaminated" tanks, and grow very large (albeit very slowly) so that they would eventually have to be removed from all but my largest tanks. Then, too, after the snails are gone, I'm left with nice fish that I really didn't want to keep in the first place, that I have to either give away, or start feeding and caring for. The Monterey Bay Aquarium could use box traps to capture mantis shrimp. Even though there are traps specially designed for mantis shrimp, the aquarium is concerned that such traps may also kill the fish in the tank. I could use certain chemical products specifically sold for the elimination of snails, but if those chemicals are deadly to one form of life, I'm not willing to bet the lives of my fish that the deadly effect of the chemicals will be limited only to snails. I have not decided to give up and start telling everyone that the snails in my tanks are there because I want them to be there. I have plans for my most snail infested tank that involve removing all plants, soaking them in anti-snail chemicals for several days, and removing all the gravel and boiling it. The problem is that this tank is heavily planted, this project would take a lot of time and work, and I have to figure out how to do this without causing undue stress to the fish. I will get to it eventually. (How many times have you sung that song when it comes to major aquarium projects?) For now, I'm just content to believe that the Monterey Bay Aquarium and I share common problems.
February 2001
23