Borbonius Anthias: The Rare Deepwater Showpiece

The Borbonius Anthias (Odontanthias borbonius), also widely known as the Blotched Anthias, Checked Swallowtail, or Yellow-spotted Anthias, is one of the most highly prized and sought-after fish in the aquarium hobby. Unlike many other anthias species, which are collected in shallow waters, the Borbonius Anthias originates from deep-water (mesophotic) reefs, often found at depths between 200 and 1,000 feet (60-300m), making it an expensive and difficult specimen to acquire and acclimate.

This striking fish displays a unique coloration that can vary, but typically features a beautiful pale pink to reddish-orange body adorned with scattered large, irregular gold or yellow blotches. Its fins, particularly the deep, lyre-shaped caudal (tail) fin, are often highlighted with bright yellow. Like all anthias, it is a protogynous hermaphrodite, with the largest female transitioning to a male in the absence of one. Males may be identified by a slightly larger size and an elongated third dorsal spine.

Due to its specialized deep-water origin, this species is sensitive to bright lighting and requires a well-established, stable aquarium of at least 100-125 gallons. It is best maintained in an environment with lower light levels and ample dark caves and overhangs to provide security and mimic its natural habitat.

Diet & Compatibility:

• Diet: The Borbonius Anthias is a Carnivore and plankton feeder with a high metabolism. A consistent feeding regimen of small amounts 3-5 times per day is crucial. The diet must be varied and include highly nutritious, finely chopped, meaty foods like frozen mysis shrimp, copepods, rotifers, and vitamin-enriched brine shrimp. It may be a shy eater when first introduced and should be fed near its hiding spots.
• Social Structure: While many anthias are kept in harems, the Borbonius Anthias is often found solitarily or in small, loose groups in the wild. In the aquarium, it is often recommended to keep them singly in smaller systems (under 180 gallons) or in a small harem (one male with 2-3 females) in very large systems, as they can be territorial toward conspecifics (members of the same species). Do not keep two males together.
• Reef Compatibility: It is Completely Reef Safe. This species poses no threat to corals or sessile invertebrates. It is a true plankton feeder and should not bother any members of the clean-up crew.
• Temperament: It is Peaceful to Semi-Aggressive. It is docile toward most tankmates, but can be easily stressed by overly aggressive or boisterous fish. Tankmates should be peaceful, such as tangs, clownfish, gobies, and other non-competing species. It requires excellent water quality and stable parameters to thrive.

Quick Facts

• Scientific Name: Odontanthias borbonius
• Primary Common Name: Borbonius Anthias
• Other Common Names: Blotched Anthias, Checked Swallowtail, Yellow-spotted Anthias
• Origin: Indo-Pacific (Deepwater Reefs: South Africa, Japan, Réunion)
• Max Size: 6 inches (15 cm)
• Temperament: Peaceful / Active (Can be territorial to conspecifics)
• Diet: Carnivore (Requires frequent small feedings of meaty foods)
• Minimum Tank Size: 100-125+ Gallons
• Reef Compatibility: Yes (Safe with all corals and invertebrates)