Keeping Orange Spotted Filefish (Oxymonacanthus longirostris)

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Rtaylor

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I get a lot of questions on my fab five (orange spotted filefish), so I thought I would share my experience with them. Warning, This is going to be long ;)

I purchased the first 3 in September of 2020 from Reefbeauties. They were shipped overnight and arrived thin, but active and otherwise healthy looking. I was prepared for a challenging period in converting them to prepared foods and had just about every food option I could find ready to go. After a short acclimation I added them to a 10 gallon tank for observation and food training.


I had researched a lot and seen people having success with Masstick, so that was the first thing I tried. I put some on the glass and to my almost disbelief, all 3 immediately started pecking at the Masstick. In less than 30 minutes I had 3 osff eating prepared food!
I’ll admit I then went ahead and added them to the DT a few hours later after confirming with additional feeding that they were indeed eating.
I added Panta Rhea Polyp & Panta Rhea Sponge pellets to their regular fare. Also TDO Chromaboost small pellets. Here’s a pic of a thin filefish (note the indented area above the eye) with a full belly.
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After some additional time all my boys would eat anything they can fit in their mouths. All 3 were male. Osff are easy to sex by looking at the ventral flap:
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There is definitely some aggression when keeping groups of these fish. A lot of chasing mostly. The males chase all the filefish and the more dominant females chase each other as well. Yet they seem to kinda school together.
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I’m getting a bit ahead of myself. A pic of the boys.
After such an easy time with the first 3, I thought it would be fun to add some females. I ordered 2 more from Reefbeauties in March of 2021 specifically requesting females. These 2 also arrived thin, but 1 was extremely thin….emaciated :(

The female in better condition immediately took to Masstick just like the boys had. The other did not take to anything and died in under 3 days , I’m pretty sure of starvation.
Adding this little lady really upped the aggression from the boys and I had a request in to Reefbeauties for 3 more females when they were available. In June 2021, they sent me 3. One was doa sadly. The other 2 were in similar condition as most of the others I had received; thin, but otherwise healthy. These ladies also immediately took to Masstick.

So in total, I purchased 8 osff, 1 was doa, 1 died within days of arrival, but 6 arrived in decent condition and immediately started eating!

A few pics of the 6:

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Ok, so if you’re keeping track….6? I said I have 5. So shortly after achieving the 1 year mark in my tank, 1 of the males disappeared. Was totally fine and then gone. My suspicion is he found a gap in my cover and a dog or cat took care of the evidence……I do have this monster prowling about.
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I couldn’t resist throwing in a kitten pic, cuz he’s just too darn adorable
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So, yes, 6 have become 5 and they are all great eaters and have been shockingly easy.
I always get asked what I feed them so I’ll go through my daily routine.
In the am, I give them 2 cubes of Easy Masstick, just split each one into 3 pieces and spread them out on the glass as the more aggressive ones will chase the others away. An auto feeder doles out a mix of 4-5 different types of pellets 3 times a day (pellet size about 1 mm is good). I also feed a frozen mix in the morning. I feed the Panta Rhea pellets 1-2 times a day and sometimes an additional feeding of frozen. Frequent, heavy feedings are important for these hummingbird fish.

They definitely eat frozen, but it is my experience that they could struggle to get enough food if someone were to feed primarily mysis or equivalent sized food. It just doesn’t fit in their mouths. They often end up spitting it back out.
Fish eggs and frozen rotifers are a size they can eat with ease. I typically have 5-6 different types of frozen mixed together with some tiny (fish eggs, etc) food included.
Now I’m going to say something controversial:

Orange Spotted Filefish Are REEF SAFE!!!
Yes, I am very aware of their natural diet. I have on several occasions added acropora millepora and other acro mini colonies thinking it might benefit them. Here is what I learned:
Osff don’t eat coral flesh, they don’t eat coral polyps, they do eat the mucus from coral polyps. Here’s a pic where you can see it’s mouth. It’s essentially a straw. It’s a single tube, not a hinged upper and lower jaw.

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For anyone who has ever seen an angel take a bite out of lps, they rip and tear the flesh. This requires a jaw that opens and closes. Osff only have a straw. Mine have barely glanced at anything other than SPS.
Ok, now for sps. The filefish will peck at it. This will cause the coral to stop extending it’s polyps. The filefish can’t eat anything other than the mucus from the polyps. Like, they are physically not capable of eating the coral flesh. That means the filefish is getting nothing from its pecking at the coral. This could absolutely damage or kill a coral frag and frustrate a hungry filefish.
A hungry aggressive osff might even manage to peck to death a mini colony.
Based off of these observations I think it is prudent that osff are not given any sps (unless they won’t eat anything else) until they are confidently eating prepared foods. (Unless you have many huge colonies that will stand up to the attention from the fish). The acros will distract them AND they won’t actually be getting any nutrients from the coral because the coral will stop extending it’s polyps. No polyp extension means no food to an osff.

The fish will still occasionally peck at some sps (I don’t have much as I appear to be more deadly to acros than any osff) but quickly give up for the readily available food they are provided.

Whew…ok, that was a lot if you are still with me. It seems that the expanding food options available are making this a more accessible fish. I hope by sharing our experiences we can up the survival rates of these beauties.
 
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Gorgeous fish, I had one that must have jumped but vanished fat and with an auto feed set with fine pellet and crushed flake to feed 5 times a day whilst I was at work so about 7 feeds a day and as you said it would eat anything it could fit in it's mouth.
Never saw it pay corals any attention but I think I was monti only sps wise back then.
 

Rtaylor

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This is awesome. Thanks for sharing.

More questions about SPS, do they only have interest in acropora millipora? What about other species of acropora, like tenuis, tort, etc? Do they show any interests at all in other SPS, like montipora, seriatopora, stylophora, etc?
Yes, I’d assume they’ll peck at any SPS. My experience has been that once they realize there isn’t any polyp extension they’ll give up and find food elsewhere. I’ve never had one damage any coral even a little. They do seem to completely ignore my purple pavona and green psammy. As long as they can find food elsewhere, I’m confident they wouldn’t damage any coral.

as I mentioned, I am a much bigger risk to coral (especially SPS) than the filefish.
 
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saf1

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This photo is priceless for two reasons. First the cat. Pretty even though I'm not a cat person you took a good photo and I can admire the beauty of said cat. What struck me even more though was the timing of the image on the TV set. The lad looking over the fence and the cat looking at you.

Makes me wonder what in the heck you have going on over there that everyone wants to take a look!!!!!
 
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saf1

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Who was it that was breeding them, or successful, in home aquaria? The name Matt rings a bell but I may have it wrong.
 

CaribbeanGirl

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I’m a newbie here although not to keeping marine fish but after owing 3 orange spot filefish (sadly now down to 2) and struggling to find info online I thought I’d add my findings to further info available on these particular species of fish and people interested in keeping them.

I’d like to thank the poster for the her invaluable information as helped me a great deal although my experience differs slightly.

when I received my 3 fish 2 were in ok condition although 1 was very thin I slowly acclimated them to hospital tank the very thin fish immediately went to the bottom of the tank and never moved from that I tried although in vain to get the fish to eat although it was too weak and never recovered 😢

my remaining 2 fish were stronger although after numerous attempts on trying and failing to get them to eat and worried they would meet the fate of the other fish I reluctantly added some small cheap acro frags to sustain them until I could get them eating other foods. I know there seems to be some hot debate on whether or not these fish are reef safe I’m sorry to say but for those wishing to keep acropora tenius these fish are definitely NOT safe I was shocked to see that not only did they eat the polyps from the frags but they also ate the tissue leaving a bare skeleton.

lots of advice suggested masstick so i spread masstick on the bare skeleton immediately they started pecking visiting numerous times throughout the day. After a few days of feeding my covering the skeleton we graduated to covering rocks as I noticed them pecking at rocks this has been hit and miss with them still preferring to peck at the skeleton.

happy that my remaining 2 are eating i added to my display tank I’m still providing masstick on the skeleton and rocks but what I’ve noticed is that these fish LOVE copepods. They spend most of the day nose down scavenging the rocks and sands for copepods which I have in abundance.

I’m still adding a variety of food to the water column for my other fish this includes a rotation of lobster & fish roe brineshrimp, mysis. I’ve noticed the biggest reaction to the lobster & fish roe and they will eat these out of the water column if it floats by but they don’t actively go for it. Just a note when I’m feeding I turn power heads & return off to give them a better chance of getting food.
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Rtaylor

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I’m a newbie here although not to keeping marine fish but after owing 3 orange spot filefish (sadly now down to 2) and struggling to find info online I thought I’d add my findings to further info available on these particular species of fish and people interested in keeping them.

I’d like to thank the poster for the her invaluable information as helped me a great deal although my experience differs slightly.

when I received my 3 fish 2 were in ok condition although 1 was very thin I slowly acclimated them to hospital tank the very thin fish immediately went to the bottom of the tank and never moved from that I tried although in vain to get the fish to eat although it was too weak and never recovered 😢

my remaining 2 fish were stronger although after numerous attempts on trying and failing to get them to eat and worried they would meet the fate of the other fish I reluctantly added some small cheap acro frags to sustain them until I could get them eating other foods. I know there seems to be some hot debate on whether or not these fish are reef safe I’m sorry to say but for those wishing to keep acropora tenius these fish are definitely NOT safe I was shocked to see that not only did they eat the polyps from the frags but they also ate the tissue leaving a bare skeleton.

lots of advice suggested masstick so i spread masstick on the bare skeleton immediately they started pecking visiting numerous times throughout the day. After a few days of feeding my covering the skeleton we graduated to covering rocks as I noticed them pecking at rocks this has been hit and miss with them still preferring to peck at the skeleton.

happy that my remaining 2 are eating i added to my display tank I’m still providing masstick on the skeleton and rocks but what I’ve noticed is that these fish LOVE copepods. They spend most of the day nose down scavenging the rocks and sands for copepods which I have in abundance.

I’m still adding a variety of food to the water column for my other fish this includes a rotation of lobster & fish roe brineshrimp, mysis. I’ve noticed the biggest reaction to the lobster & fish roe and they will eat these out of the water column if it floats by but they don’t actively go for it. Just a note when I’m feeding I turn power heads & return off to give them a better chance of getting food.View attachment 73031View attachment 73032
I agree these fish can kill an acro frag, though, I don’t think they are eating the polyps and flesh. They damage the tissue with the constant pecking which leads to the death of the coral. They may consume flesh and polyps incidentally if it comes off the frag, but from what I have seen, they aren’t getting much (if any) food from these efforts. Which is why I only recommend offering it as a last resort. Once the fish learn to eat prepared foods, they typically won’t waste energy pecking at a frag that isn’t yielding any food. Did you try the Masstick before adding the coral?
 

CaribbeanGirl

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Yes tried the masstick before adding the coral but they just wasn’t interested until I put it on the frag I’m now slowly training them to eat from the glass after graduation from sticking to rock. Eventually I’m hoping to get them eating from a butterfly feeder. Unfortunately they definitely do eat the tissue of the coral along with the polyps I watched where they pecked and would leave bare spots on the frag until nothing was left. In an effort to learn more on their feeding habits I’ve placed a camera to tank to constantly record and will sacrifice another frag to get a more in depth view. You are right though they do not eat all sps they are actually quite selective on which ones they go for as some frags have gone untouched.
 

Rtaylor

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Yes tried the masstick before adding the coral but they just wasn’t interested until I put it on the frag I’m now slowly training them to eat from the glass after graduation from sticking to rock. Eventually I’m hoping to get them eating from a butterfly feeder. Unfortunately they definitely do eat the tissue of the coral along with the polyps I watched where they pecked and would leave bare spots on the frag until nothing was left. In an effort to learn more on their feeding habits I’ve placed a camera to tank to constantly record and will sacrifice another frag to get a more in depth view. You are right though they do not eat all sps they are actually quite selective on which ones they go for as some frags have gone untouched.
Hmm. I’d be interested to see a video of them eating coral flesh. Pecking at the flesh excessively does kill it, but I have yet to see an osff with any coral flesh or polyps in its mouth. When a coral is stressed, it will bleach, which causes it to turn white, the damaged tissue then likely dies. I’m not saying it’s impossible, and I 100% agree they can kill coral, but I’m not convinced they are eating it. It wouldn’t make sense for them to kill their extremely slow growing food source from an evolutionary standpoint. And their mouths……they can’t do anything but peck and suck. They only have an extremely minimal ‘bite’ range which doesn’t seem sufficient to rip out coral polyps or bite off coral flesh. Seeing the way they eat Masstick, sometimes they have a hard time sucking that up and it’s not firmly adhered to a skeleton. They don’t even try to do anything except peck at the Masstick to suck it up their little tube mouths. They don’t try to ‘bite’ it. They almost seem frustrated with it. Again not trying to be argumentative, I have watched osff pecking at coral as I added some initially thinking it might benefit them. It would be great if you could document them actually consuming coral as it would be useful for adding to the knowledge on this species. I don’t think seeing white spots would necessarily indicate that they are successfully eating it, just successfully damaging it. Perhaps inspecting the coral immediately after would be able to tell us if the flesh is missing or just bleached and damaged initially.
 
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