For a zooplanktivore such as Anthias, who are frequent feeders, withholding food isn’t necessarily advantageousQuestionI’ve been told that it’s a good idea to avoid feeding aquarium fish on occasion, for example once every week or once every other week. I guess this stands to reason because fish in nature can’t always get a meal. Do you agree with this, and if so, how frequently do you recommend doing it?” – Submitted by Candace Brown Answer While I don’t have an issue with the practice of occasionally fasting fish, I’m always wary of making any sort of blanket recommendation such as “Marine fish should be fasted every X number of days.” In my opinion, a much better approach is to think in terms of feeding in a manner appropriate to the particular species—which may or may not include fasting. For instance, some predatory species, such as groupers and moray eels, naturally take in large prey items in one sitting and then go without eating for a relatively long interval until another prey item happens along. With these fish, it may be appropriate to feed only once or a few times per week and then allow them to fast in between meals. On the other hand, zooplanktivores and herbivores (such as anthias and many of the tangs/surgeonfishes respectively) naturally feed frequently, if not continuously, throughout the day. Thus, in an aquarium setting, it’s appropriate to provide multiple small feedings each day for zooplanktivores and continuous grazing opportunities for herbivores.
While a fish might seem to have an exclusive diet, they’ll often chow down on “off-menu” offerings, as wellCarnivorous fish eat meat, herbivorous fish eat algae/plants, and omnivorous fish eat both. That’s the order of things, and any fish we buy for our aquariums should fit nicely into one of these categories so we know exactly what to feed it, right? Well, if that’s the case, why on earth do my blue-chin triggers (Xanthichthys auromarginatus)—carnivores by nature—always beat my tangs and foxface to the dried algae sheets I offer and actually eat the lion’s share? After all, FishBase describes X. auromarginatus as “[forming] loose aggregations a few meters above the bottom where it feeds on zooplankton, particularly copepods.” Nowhere in this statement do you see, “Oh yeah, and it likes to tear into algae from time to time, too!”On the flipside of the coin, just as my triggers seem to enjoy ordering “off-menu,” my herbivorous yellow tang (Zebrasoma flavescens), Atlantic blue tang (Acanthurus coeruleus), and one-spot foxface (Siganus unimaculatus) will greedily gobble up any meaty items that they can fit in their mouths as well. What gives?
Astraea snail chowing down on nuisance algaeThis past year, I rediscovered how great an army of snails can be. At Tidal Gardens, we go pretty light on cleanup crews in general. For example, there really aren’t any hermit crabs to speak of in our systems. In 5,000 gallons of reef tanks, there may be only one or two hermit crabs. Most likely they arrived as refugees from local customers taking their tanks down who needed to re-home some of their inhabitants. I am not a fan of crabs because there is always a risk they might kill something they should not be killing, like another member of the cleanup crew or a coral. Long story short, I don’t trust them. I don’t have the same level of distrust for snails