How Do We Measure Success with Hard-to-Keep Marine Species?

“What do you mean the bluestreak cleaner wrasse is hard to keep? I once had one in my half-gallon pico tank for a year and a half, feeding it nothing but frozen brine shrimp and flake food, and it was as healthy as can be!”

If you’ve spent any amount of time in this hobby, you’ve probably heard similar assertions about success with notoriously hard-to-keep marine species—cleaner wrasses, ribbon eels, Moorish idols, Dendronephthya spp. corals, sea apples, and others—and wondered whether there was any truth to them.

I don’t doubt for a minute that some hobbyists succeed in keeping really challenging species alive and healthy. In fact, I know they do. But the trouble with such anecdotes as they apply to the average hobbyist is two-fold:

1. They tend to create the false impression that the difficulties associated with keeping certain challenging species healthy for the long term are overstated (they usually aren’t).
2. They raise the question, “If so-and-so succeeded with [insert name of preposterously difficult animal here], why shouldn’t I try it?”

Here are a few reasons you might want to think twice before attempting to keep any species that has a reputation for confounding even the experts:

Success is the exception

Some hobbyists who succeed with really challenging marine species are just exceptionally dedicated and willing to go to any lengths to meet the species’ unique requirements—for example, providing a steady supply of live stony corals to obligate-corallivore butterflyfishes, or serving up live starfish to harlequin shrimps. But even in these ideal circumstances, success with these animals is still hit-or-miss.

In other cases, the hobbyist might have simply lucked out in getting a specimen that just happens to be more hardy and adaptable than is typical for the species, e.g., a pinnate batfish that takes immediately to eating a variety of prepared foods. But again, such luck is the rare exception, not the rule.

True success is measured in years

One of the giveaways in my (admittedly exaggerated) example above is the length of time the fictitious hobbyist purportedly kept the specimen alive. Properly cared for, most marine fishes can live for many years in captivity—some for decades. In other words, a “success story” measured in months to a few years is nothing to brag about. I’ve seen starved fish cling to life for upwards of a year or even longer before finally giving up the ghost—and looking relatively healthy for much of that time.

What about corals and other sessile invertebrates? We can’t even really say how long they’re capable of living under the right circumstances. Could be indefinitely. Whatever their potential longevity may be, it’s safe to say that keeping a challenging species, such as a Tubastraea sp. coral, alive in an aquarium for merely a matter of months to a handful of years isn’t cause for celebration.

We have to know our limits

Before taking on the challenge of keeping any marine organism with highly specialized needs, we really must ask ourselves whether we have the willingness, ability, time, and resources to do whatever it takes to meet those needs for the duration of the animal’s potentially very long lifespan. If the answer to any part of that question is no, it’s best to leave the animal at your dealer’s—or, in some cases, in the ocean.