gist41980

October 26th marked the 3 month milestone for keeping a pair of female Beaked Leather Jackets (Oxymonacanthus longirostris, Orange Spotted Filefish). I am not sure how one measures the success of keeping fish, but I consider this experience to be a successful one. They are active, robust and are very interesting fish to watch.

This success is not mine alone. I learned from the experiences others have shared (both successes and failures) in online forums. One of the very first decisions I made was to seek out a pair that had been weened off of a strictly sps coral polyp diet (their natural diet) and onto a varied diet of prepared foods. At the time I did not have the space or resources to attempt the weening process myself. I did not have an extra space or tank to attempt this. So, I waited patiently until there was a pair on Diver’s Den. I was quick enough to snatch them before someone else (my first attempt to buy them failed as someone swooped in an bought them while i gazed at their picture for an extra 10 seconds!). Diver’s den had weened them onto thawed mysis shrimp and nutramar ova, so that task was done for me!

When introduced into my tank they were a bit skinny and at only nutramar ova. They also picked at the polyps on my Green Slimer Acro, millipora, pocillopora and a bit at my birdsnest. Over the course of time their figured out that sera marin granules, cyclopeeze, flakes and mysis make for good eating as well. I feed the tank twice a day and with each feeding I always include some nutramar ova as that seems to be their favorite. These days they look healthy and plump!

They have picked at sps polyps resulting in polyp retraction for most of the day, but they have not killed or stressed any coral to the point of color loss. If you like seeing polyp extension this fish is not for you!

If you decide to get a BLJ that has not been pre-weened, by all accounts be prepared to spend a lot of time and work to try and ween it onto prepared foods.

A special concern of mine is that these are very active fish with a high metabolism. They need to have food available to them throughout the day. I had read someone elses experience with these fish and they came across a food called Rogger’s reef food. It is frozen mixture of all sorts of good seafood that can be put in a Norri clip and will hold together without dissolving in the water over time. It did not take long for the BLJ’s to realize that it was food. In the mornings I put a small piece in the clip and they will pick at it throughout the day. In general it lasts them until about 4pm each day.

The clip of food today at 5:15pm


While the fish are fun to watch during the day, they are very interesting to observe at night. As the lights dim they retreat to their favorite spots. They will then anchor themselves using their top spike like fin, into a coral or rock, go ridged and disguise themselves to blend in. They then remain very still and sleep there for the night.







Three months have passed and the Beaked Leather Jackets are as healthy as ever!

Feeding time 10-26-11 (By the way, youtube has very useful tools that allow you to adjust the color temperature of your video, very helpful to offset the blue color you often see. Play around after you upload a video)