Acreichthys tomentosus “Aiptasia-eating Bristletail Filefish”, Captive Bred

Yes, we have captive-bred Bristletail Filefish for sale! No wild-caught individuals here. These fish are produced by both ORA and Biota Palau, and both are available somewhat regularly, so if you had a preferred vendor (or if you were trying to create unrelated pairings of juvenile fish, we could certainly help in that department).

It seems that a little over a decade ago, the Bristletail or Matted Filefish, Acreichthys tomentosus, grabbed everyone’s attention when it became widespread knowledge that this species relished eating pest Aiptasia anemones. This species also grabbed headlines as the first species of Filefish (Monacanthidae) to be spawned and reared in captivity at the hands of talented German aquarist Iris Bönig, and proved to be potentially one of the easier marine fish to rear with a short 15-day larval duration.

Since that time, this species has become a mainstay in the aquarium industry. Wild caught individuals are readily available, but one thing I’ve noticed and seen with other aquarists as well, is that this species is prone to bacterial infections. So you get this fish that outwardly appears healthy, and then a couple weeks later it has sores and dies. I have not seen this happen with any of the captive-bred Bristletail Filefish that have come through the fishroom!

This species is arguably a bit of a chameleon; they can readily shift coloration from green to brown to gray, showing their mottled pattern or losing it completely, all based on their mood. They are easily sexed; males have a patch of transparent bristles on each side of the caudal peduncle; this is absent in females. Care must be taken when netting this species; the dorsal spine has numerous backwards-pointing barbs that make it incredibly difficult to remove if it becomes entangled; it’s easier and probably safer to move this species with wet hands.

Their reputation for eating Aiptasia is deserved, but note that they can and will turn on other cnidarians, particularly if they’re not well fed and the Aiptasia population is decimated. LSP like Acans and Blastomussa are among primary targets.

Typically, the captive-bred filefish are shipped out at around 1 to 1.5″ in length; this species can reach up to 5″ in length.