Common name: Bristle-tail Filefish

General Information

The Bristle-tail Filefish, scientifically known as Acreichthys tomentosus, is a fascinating species appreciated by aquarists for its unique ability to control aiptasia populations in reef tanks. This species is recognized for its cryptic appearance, allowing it to blend seamlessly into its surroundings with its mottled brown and green coloration. The Bristle-tail Filefish has earned a special place in the saltwater aquarium hobby due to its practical utility and intriguing behavior.

While not as flashy as some other marine fish, the Bristle-tail Filefish is valued for its ecological role in aquariums. It helps manage pest anemone populations, making it a beneficial addition to reef systems plagued by aiptasia outbreaks. Its ability to change color and texture to match its environment adds an extra layer of intrigue to its presence in the tank.

Care

The Bristle-tail Filefish is suitable for intermediate to advanced aquarists due to its specific dietary needs and occasional behavioral quirks. It thrives in well-established aquariums with plenty of live rock and hiding spaces. These fish are known for their adaptability, but they require stable water conditions and a varied diet to flourish.

A tank of at least 100 liters is recommended for a single individual, with larger setups preferable if keeping multiple fish or other species. Provide ample live rock and structures to mimic their natural habitat, offering both security and foraging opportunities.

Diet and Feeding

In the wild, Acreichthys tomentosus primarily feeds on small invertebrates, algae, and polyps, including the notorious aiptasia anemones. In captivity, they should be offered a varied diet that includes frozen mysis shrimp, brine shrimp, and high-quality marine pellets. Supplement their diet with algae-based foods to ensure balanced nutrition.

Feed them once or twice daily, observing their eating habits and adjusting portions to prevent overfeeding. It's important to monitor their impact on coral polyps and adjust their diet if they begin to nibble on desirable corals.

Behavior and Compatibility

Bristle-tail Filefish are generally peaceful but can be semi-aggressive towards similarly sized or shaped fish, especially in smaller tanks. They are best kept singly or as a pair in larger setups to minimize territorial disputes.

These filefish should be housed with caution in mixed reef tanks. They are known to occasionally nip at soft corals and polyps, which could be problematic for coral enthusiasts.

They are compatible with a variety of peaceful reef-safe species but may exhibit aggression towards conspecifics or similarly sized fish, especially in cramped conditions.

Symbiosis

While Acreichthys tomentosus does not have a well-known symbiotic relationship, its natural role in controlling aiptasia populations in reef environments can be considered a form of ecological balance. This role is replicated in aquariums, where they help manage pest anemone outbreaks.

Health and Common Issues

In captivity, these filefish can live for several years with proper care. Selecting healthy individuals involves looking for active, alert fish with intact fins and a healthy appetite. Avoid fish that appear lethargic or have visible signs of distress.

Routine care includes maintaining optimal water quality, providing a varied diet, and monitoring for signs of stress or illness. Regular water changes and a stable environment can prevent many common health issues.

Habitat

Acreichthys tomentosus is naturally found in shallow coastal waters and coral reefs across the Indo-Pacific region. They prefer environments with plenty of live rock and crevices for hiding and foraging. In captivity, replicating these conditions with stable water parameters and moderate flow is essential for their well-being.