Blotchy Deepwater Anthias

Ondontanthis borbonis, also called the Checked Swallowtail.

Text and image by Tanne Hoff
Excerpt from Rarities, CORAL, January/February 2010

If you delve into cutting-edge books by authors like Helmut Debelius, Rudie Kuiter, Scott Michael, and Roger Steene, you will come across creatures that you dont expect ever to see, except in photos. But dreams do sometimes come true, and thus it happened that I was able to buy specimens of the rare and unusual Blotchy Anthias, sometimes called the Checked Swallowtail Anthias.

This species originates from the Indo-Pacific: its distribution extends from Japan to South Africa. These fishes live at great depths (according to Fishbase, (according to Fishbase, 305–1,000 feet / 92–300 m), so I had never anticipated that specimens would appear in the aquarium trade.

In April 2007, however, I heard about six individuals that had been imported, so I traveled without further ado to Belgium so I could, at least, photograph them. I bought two of the six, but unfortunately they died within a few days. This first importation was, however, followed by more, and according to a Dutch importer, around 1,200 Odontanthias borbonius have been exported from Bali. Because an aquarist friend of mine had enjoyed success in the maintenance of these fishes over a period of a year, and because they were now arriving in appreciably better condition, I decided to have another go.

In contrast to the initial negative experiences, nowadays it is mainly positive reports about the Blotchy Deepwater Anthias that are coming in from hobbyists all over the world. In general it can be said that these fishes are probably not difficult to keep. Initially a little shy, they rapidly come to accept artificial foods such as live Mysis. Finer foods, such as lobster eggs, bosminids, and Cyclops, are also taken, but even tiny juveniles seem to prefer somewhat larger foods, so Mysis and krill are recommended. Later they will take a greater variety of foods, even dry fare, and it is astonishing what large morsels they are able to swallow.

Anyone who wants to keep these splendid fishes should provide them with a peaceful tank. Blotchy Deepwater Anthias are sedate swimmers, and in general they do not harm other fishes unless the latter are so small as to be mistaken for food. If the other fishes in the aquarium are too aggressive, O. borbonius will go into hiding, and this may affect its food intake. At first the species can be kept in a group without problem, but with increasing age there are often squabbles; keeping them in pairs seems to be the way to go. As with other Anthias, these fishes are able to change their sex.

Conditions in their natural habitat should be taken into consideration when placing them in an aquarium: because O. borbonius lives at great depth, the lighting should not be too bright, and rocky overhangs should be provided for hiding places. Various aquarists advise that this fish should be kept at temperatures between 72 and 77F (2225C), but temperatures at the lower end of the scale may be betterafter all, the water at greater depths can be rather cool. O. borbonius can be afflicted with parasitic worms. It might be helpful to worm these fishes prophylactically.

I have come to the conclusion that this fish, like other species from great depths (for example, Liopropoma sp. and some wrasses), can be maintained in the aquarium. Experienced aquarists who are able to offer this Anthias a suitable tank will find that these fishes, with their almost prehistoric appearance, are extremely interesting to keep.

References
Debelius, H. and R. Kuiter. 2006. Atlas der Meeresfische. Kosmos, Stuttgart, Germany.

On the Internet
http://www.fishbase.org/Summary/SpeciesSummary.php?id=23333

Excerpt from Rarities, CORAL, January/February 2010. Subscribe to read the full issue.