Having been banned from RC several years ago over my disagreement with a rule that's since been changed, I've asked Ummfish to post this message for me.
Peter is largely right on with his intepretation of "oblitatory" in my opinion...i.e. competitive pressures in the wild may force the Harlequin Filefish to corals as a food source as it's otherwise inable to compete (in the wild) over other food sources. It has been demonstrated through field research that when coral reefs die off, the Harlequin Filefish vanishes from the reef extremely rapidly. The research also suggested that they do not simply move to a new reef, but that they actualy die off very quickly.
Early in my care, my own observations on coral feeding suggested that maybe they didn't actually feed on the polyps themselves....that certainly has been proven false in some of my later observations. However, there is some truth that I think Ummfish first pointed out to me last year - their natural diet according to the scientific literature also includes "algae". And they certainly DO feed on algae in my tanks on occasion, especially early on. But in truth, the revelation of the research above proves that without live corals in the wild, this fish is unable to live....it's not like they can suddenly shift to feed on algae exclusively when the coral reefs die.
I chose my wording in the CORAL article very carefully. Give the article multiple reads if you must to get the full impact, and if you have questions, find me on some other forum (I'm a member of most) and shoot me an email or PM - I'm happy to discuss. Frankly, when I wrote such an article, I took on the responsiblity of being a "caretaker" of the information I presented, precisely so it isn't misinterpreted. If my experience makes me the ambassador for this species, if that's my obligation as a result of my "promotion", I fully accept that role. The last thing I or anyone else would want is for people to get the wrong impression of this very challenging species.
In the introduction of my article, I wrote "Only later does the hobbyist learn that the Harlequin Filefish is an obligate corallivore..". Later, under the "Dieatry Myths" section, I wrote, "we must address the core believe that [Harlequin Filefish] will die without live coral flesh in their diet...This is simply not true." Both of these statements appear to be completely true and yet are not mutually exclusive. Fish aren't going to live and spawn and produce viable offspring if there is some critical element missing in their diet....nor are the captive bred offspring going to survive without that critical element. I believe my longest term fish are coming up on 1.5 years in captivity for me personally? They're certainly not starving, all skin and bones. I believe the theory of a "critical nutritional element" for Harlequin Filefish is disproven, as is the fact that in the wild, they are most certainly obligate corallivores.
Personal annecdotes from others in the field have suggested that the freshly settled juvenies of various Corallivorous Butterflyfish species can be trapped at that stage, and will eagerly accept perpared foods (i.e. flake) and can be grown out to marketable size without issues. This too, suggests that coral does not hold some magical nutrient that the fish must have in order to thrive. And that again, completely jives with Peter's comment above - corallivorous fish are not very eager to accept something else as a substitute. Training Harlequins onto prepared foods is very hard in my experience, but it is doable and repeatable.
There are two other, more common possiblities that can explain the dietary issues this species can face, and I borrow these from the Seahorse keepers. Quite simply, if you don't feed a Seahorse multiple times per day, it will starve, no matter how much food it gets at that one sitting. So too, I fear, for the Harlequin Filefish. That certainly seems to be the case. The other possibility - Worms. If there fish is burdened by GI-tract parasites, these could easily explain nutritional deficiencies and wasting away despite heavy appetites. It's only a theory, but worming Harlequin Files might prove beneficial to their long term care.
Still another possiblity, not borrowed from Seahorse keepers, is the possiblity of a fish being drug caught. This is certainly a fish that might be difficult to extract from a live coral head without drugs. We all know that even if a drug caught fish survives to make it to your tank, it quite certainly can sustain internal organ damage that in the shortish term, can cause the fish to ultimately not survive despite good appetite and demeanor. Any one of these causes can explain the wasting away for a healthy fish. Of course, that assumes that you GET a healthy fish to start with, and in truth, the MAIN cultprit with the Harlequin Filefish is that too often, it already has one foot in the grave by the time it makes it to your LFS. No different that most Mandarins. The less time this fish spends in the chain of custody between harvest and you, the better.
We also should address that captive lifespans for this fish as a WC specimen have been shown to typically be in the range of 3-5 years based on other hobbyists successes, with or without live coral in the diet. I think it's foolish at this point to assume whether to know if a one year lifespan on a WC adult fish is good or bad, given that we don't have any data on the natural lifespan to begin with. There are species like Neon Gobies that live a year, or Pearly Jawfish that typically live 2-3 years in the wild. For all we know, a WC Harlequin Filefish might already be 1-3 years old when caught...if the natural lifespan is 4 years, and we keep the fish alive for a year, perhaps we're doing "GREAT". Of course, just as easily, it could be that this species could live decades like some clownfish are known to. In that case, 1 year is pretty darn bad. We simply do not know the wild lifespan, so we should refrain from judging 1 year's success as good or bad at this point.
What my article didn't cover was the reasons for my losses, and I in fact purposely chose NOT to disclose those reasons because they might actually provide further encouragement to hobbyists who weren't ready for this species. For example, if I told you guys all that the 5 losses out of 17 were fish that died in a heater failure or power outage, that would be fundamentally different than if I told you guys they all died from starvation. While neither scenario represents the true causes for the 5 losses, the fact is, I can personally explain and justify these losses, and I do not hold these losses against the fish's reputation (i.e. the losses I encurred are not necessarily the fault of the fish's needs, but the fault of the caretaker and chain of custody). So, to have explained these losses would likely have only served to minimize the true risk with this species and encourage people to take the same risk that I did. So, better to say simpy that I lost 30% of the Harlequin Filefish I tried. Better to say that as a WC fish it is very sensitive and demanding. This is very much an EXPERT ONLY species, and what didn't make it into the article is that at the time of writing it, ever hobbyist who has had success with the species at that time probably had a decade or more of hobby experience. So think about that. Not for the newbie, and not for someone with 2-3 years of experience. Only for the very dedicated and experienced hobbyist.
Writing the CORAL article for me was an easy choice, but for CORAL Editor James Lawrence, he was very careful to make sure that my article did not paint this species in any new light that would lead to hundreds of people rushing out to try it. For anyone interested in a bit more of that, I'd suggest the article Ret Talbot did talking to me & Witt about our back-to-back articles on the breeding of what are "expert only" fish, and the "ethics" of articles such as the one in question -
http://www.bluezooaquatics.com/resources.asp?show=373
Judging by the minimal level of inquiries I've had, and the fact that the only really solid inquiry has come from a professional aquarist and a public aquarium, I'm pleased. I hope this means we acheived our goal in presenting the info without creating a surge in demand for the species. So too, the article improved the sales practices at one of the two online vendors that sells this species, and for that, I can only be thrilled! It is certainly better that my experiences be out there than not, if only that more folks with cite it, and thus more folks who "inadvertently" purchase the fish might have a better shot at keeping it alive. And yes, I certainly do hope that my experience leads to breeders all around the world producing captive bred Harlequins, because the captive bred babies are nothing short of spectacular fish that readily take prepared foods and certainly could be easily kept by moderately experienced aquarists ....that's the kind of fish that fish breeders need if they're going to stay in business and help us save our hobby.
FWIW,
Matt (formerly MWP
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