Borbonius Anthias

The Borbonius Anthias, also known as the Blotchy Anthias or Checked Swallowtail, is a spectacular saltwater fish with a soft pink-to-lavender body covered in irregular golden-yellow blotches. Large reflective eyes, tall dorsal spines, and violet, blue, and green highlights along the fins give this deepwater species exceptional color and detail under aquarium lighting.

Native to the Indo-Pacific, Odontanthias borbonius ranges from South Africa to Palau, north to Japan, and south to Indonesia. It inhabits mesophotic and deep rocky reefs at approximately 70–300 meters, remaining close to caves and protected ledges. Adults reach about 6 inches in standard length and are often observed singly near deep reef shelters. 

Its bold pattern, compact but substantial build, and generally calm behavior make it a desirable centerpiece for a mature reef aquarium or peaceful fish-only aquarium. Successful care depends on shaded retreats, excellent water quality, gentle acclimation to bright lighting, and frequent offerings of appropriately sized meaty foods.

Quick Care Guide

Care Level: Moderate
Minimum Tank Size: 100 gallons
Temperament: Peaceful
Diet: Carnivore / Planktivore
Reef Safe: Yes
Region: Indo-Pacific—South Africa to Palau, north to Japan, and south to Indonesia
Scientific Name: Odontanthias borbonius

The species reaches approximately 6 inches in standard length and naturally occupies deep reef habitats. 

Tank Requirements

Provide a mature aquarium with substantial live rock arranged into deep caves, shaded overhangs, vertical ledges, and narrow retreats. Leave open space through the middle of the aquarium for feeding and short periods of midwater swimming, but ensure that secure shelter is always nearby.

Because the Borbonius Anthias originates from deep, dimly illuminated reefs, newly introduced specimens may remain hidden under intense reef lighting. Provide shaded areas and allow the fish to adjust gradually rather than forcing it into a brightly exposed aquascape. Established individuals often become more visible once they associate the aquarist with feeding. 

Moderate, well-distributed water movement and excellent oxygenation are appropriate. Include calmer zones inside the rockwork where the fish can rest without fighting strong flow. A specialized substrate is not required, although reef sand or fine gravel works well. Use a secure lid or mesh cover, particularly during acclimation.

Diet and Feeding

The Borbonius Anthias is a carnivorous planktivore that naturally feeds on zooplankton around deep reef caves and rocky ledges. Offer small foods that remain suspended in the water column or drift close to the fish’s preferred shelter. 

Suitable foods include mysis shrimp, enriched brine shrimp, copepods, calanus, finely chopped krill, shrimp, clam, squid, and quality frozen carnivore blends. Small slow-sinking marine pellets may be accepted once the fish is established.

Feed two to three small portions daily. Newly imported specimens can be reluctant to eat and may respond better to enriched live brine shrimp, copepods, or finely chopped seafood delivered near their cave. Confirm that the fish is maintaining a full body profile and receiving enough food before faster tankmates consume it. 

Temperament and Tankmates

This species is generally peaceful toward unrelated marine fish but may become territorial with other Borbonius Anthias or similarly shaped anthias competing for shelter. Keep a single specimen in most aquariums. A compatible pair may be attempted in a substantially larger system with multiple caves, but randomly combining mature individuals can result in aggression.

Suitable tankmates include peaceful tangs, rabbitfish, clownfish, cardinalfish, fairy wrasses, assessors, gobies, and other non-predatory community fish. Avoid aggressive triggers, large dottybacks, predatory groupers, and highly competitive fish that may intimidate it or prevent it from feeding.

Introduce the Borbonius Anthias into a quiet, established aquarium and allow it time to claim a retreat. Initial hiding is expected, especially under bright lighting or when active tankmates are present.

Reef Compatibility

The Borbonius Anthias is considered reef safe. It does not normally damage healthy stony corals, soft corals, zoanthids, anemones, clams, or other sessile reef inhabitants. It is suitable for coral-focused displays when its deepwater acclimation needs are accommodated. 

Copepods, amphipods, larval crustaceans, and other very small planktonic animals may be consumed as part of its natural diet. Established ornamental shrimp, crabs, snails, and other larger reef invertebrates are generally ignored.

Water Parameters

Temperature: 72–78°F
Specific Gravity: 1.024–1.026
pH: 8.1–8.4
Alkalinity: 8–12 dKH

This deepwater anthias benefits from excellent oxygenation and temperatures toward the cooler end of the tropical marine range. Captive broodstock have been maintained in cool, dim conditions designed to reflect their natural habitat. Avoid rapid temperature changes and prioritize long-term stability. 

Common Considerations

• Provide shaded retreats: Newly introduced specimens may remain hidden under intense reef lighting.

• Feed several small meals: Frequent offerings of plankton-sized meaty foods support healthy body condition.

• Keep singly in most aquariums: Territorial behavior may occur between conspecifics and similar anthias.

• Allow a patient acclimation period: A reserved new arrival may feed only near its cave before becoming comfortable in open water.