A recent shot of Paul B’s 40+ year old reef aquariumMany marine fish can survive in captivity for decades, and many corals and other sessile invertebrates can hang in there, well, who knows how long. In any case, maintaining a marine aquarium “for the long term” can mean an awfully long time. Just ask Paul B, author of The Avant Garde Marine Aquarist. His current tank has been up and running with much of the same livestock since somewhere around the Second Battle of Bull Run (being a New Yorker, Paul presumably wouldn’t have called it Second Manassas). My style of aquarium keeping also leans toward the long-term, so I thought I’d dedicate today’s post to what I consider the pros and cons of this approach (versus keeping specimens for relatively brief periods and frequently changing up your livestock) for those whose hobby experience doesn’t yet span decades:Pros: You gain a new respect for the growth potential of specimens—and thus the benefits of spacious housing. For example, reading that fish species X can reach Y inches/centimeters in maximum length doesn’t compare to actually seeing the genuine article fully grown and swimming around in your tank alongside a bunch of other fully grown specimens.
Sometimes external stressors can cause aggression amongst tankmatesFish wounds and injuries can result from a variety of different influences, with tankmate aggression being among the more commonplace. Unfortunately, hobbyists don’t always recognize this problem right away when it manifests itself. Jay Hemdal, Curator of Fishes and Invertebrates for the Toledo Zoo, explains why in the following excerpt from his book The Salt Smart Guide to Preventing, Diagnosing, and Treating Diseases of Marine Fishes: Tankmate aggression This is a potential issue in any marine aquarium that houses more than one fish. In the most serious instances, where the aquarist severely underestimates the ability of one fish to injure another, aggression actually takes the form of predation. There are also cases of fish living peacefully side by side for years and suddenly beginning to fight. Home aquarists are often in denial that any aggression is taking place because, with the exception of the most severe cases, it is very difficult to “catch them in the act.” Take, for example, a case of minor aggression where one fish is “tagging” another one (damaging a fin with a bite) at a rate of once or twice a day. What are the chances that an aquarist is going to see the aggressive act?