When it comes to acquiring food, fish will take the path of least resistance. And one of the best ways for a fish to score an easy meal is to snatch morsels away from their glacially slow-moving invertebrate tankmates. Heck, it’s practically like taking candy from a baby, except babies usually cry a lot louder when they’re robbed of treats.
For hobbyists who keep corals or other invertebrates with a high demand for regular targeted feeding—e.g., many LPS corals and anemones—such food thievery can be a genuinely aggravating issue. The good news is, using one or more of the following techniques, it’s often possible to eliminate, or at least reduce, this bad behavior:
Distract the culprits
You may be able to buy your coral a few precious moments at mealtimes by first delivering food to the fish in another part of the tank and then quickly target feeding the coral. Of course, this is only effective if the fish haven’t already learned to identify the coral in question as a source of easy victuals. In that case, they’ll likely just gobble up their own food and then proceed to shake down the coral anyway.
Feed the coral at night
Feeding corals after dark offers a couple advantages. One is that many corals naturally feed at night and, thus, typically extend their feeding tentacles at that time. Another is that many fish will go right into their favorite nighttime resting spot after lights out and are less focused on finding food. These circumstances facilitate easier coral feeding and greatly reduce the likelihood of thievery.
Tempt the coral first
Speaking of those feeding tentacles, there’s an easy way to encourage them to emerge whenever you’re ready to feed the coral—even in broad daylight. Just gently squirt a small amount of the water used to thaw or rinse the food onto or upcurrent of the coral and wait a few moments. After the coral detects the chemical signature of food in the water, it should go into feeding mode and extend its tentacles. Then you can go ahead and target feed it.
This technique doesn’t guarantee that fish won’t still try to steal the food, but being physiologically poised to actively feed when a meal is delivered gives the coral at least a fighting chance of holding on to its rations.
Isolate the victim
If you’re dealing with a really persistent piscine coral food thief, your best bet is to create some sort of physical barrier between the coral and would-be burglar at mealtimes. For example, in the past, I used to cover my open brain coral with the top third of a three-liter plastic soda bottle at feeding times. With this makeshift enclosure, I could feed the coral via turkey baster through the opening at the top while keeping my greedy percula clownfish completely at bay. Once the coral finished feeding, I just removed the bottle top, dried it off, and put it away until the next feeding. Another popular choice is to use one of those plastic mesh baskets that berries are packaged in at the supermarket.
Basically, any similar object will suffice as long as it’s made of aquarium-safe material, allows water to flow through, provides some sort of easy access for food delivery, and excludes fish. Just make sure the enclosure is sized such that it can be put in place and removed without contacting or damaging the coral.
What’s your trick?
So, fellow salties, how have you overcome the issue of fish stealing coral food? Let us know in the comment section below.
