The Arrowhead Basslet (Belonoperca chabanaudi) is a slender, elongated predator that reaches roughly 6 inches at maturity. Body color ranges from dark brown-black to a smoky greenish-blue, accented by blue-edged black spots on the first dorsal and pelvic fins, a luminescent blue dorsal fin, and a yellow patch near the anal and second dorsal region. The species occurs through the Indo-Pacific, with Coral Sea populations being the most familiar to collectors. On the reef it is a shadow dweller, hovering along dark walls and inside caves, frequently oriented upside down beneath overhangs. It reaches the aquarium trade only occasionally, which makes it a genuine prize for keepers of uncommon reef fish.

Plan on a 75-gallon aquarium as the floor for a single adult, and step up to something in the 125- to 140-gallon range if a pair is the goal. The layout matters as much as the volume: build rockwork that creates deep caves, ledges, and shaded vertical faces, then leave generous open water in front of that structure so the fish can hover and drift as it does in the wild. Subdued or partially shaded lighting over at least a portion of the display encourages the basslet to spend more time in view rather than retreating permanently into the rocks. Stable tropical conditions and strong water quality suit it well, and its overall hardiness once settled is one of its better traits.

In nature this is a strict carnivore that ambushes small fishes and invertebrates from the cover of caves and shaded walls. The mouth is large relative to the body, and the hunting strategy is built around short, sudden strikes on anything that fits. That predatory design should shape every feeding decision made for it in captivity.

Captive specimens accept meaty foods readily and are generally described as voracious feeders. Offer frozen or live mysis and brine shrimp along with small pieces of fresh seafood such as shrimp, scallops, clams, and fish flesh, plus frozen squid for variety. Chop items to a size the fish can take in a single strike, and feed several times per week or daily in smaller portions to keep condition without overloading the system. Rotating between shrimp-based and fish-based items helps maintain interest and nutritional balance.

Frozen Mysis Shrimp Live Brine Shrimp Frozen Brine Shrimp Chopped Shrimp Scallop Pieces Clam Meat Frozen Squid Fresh Fish Flesh
Expect a deliberate, ambush-oriented fish rather than a constant swimmer. It positions itself near cave mouths and shaded rock faces, often hanging inverted, and moves with sudden purpose when food or prey appears. Temperament is semi-aggressive, and the combination of attitude and a large mouth means tankmate selection deserves real thought. Companions should be similar in size or larger and confident enough to hold their own; small, timid fishes are at risk of being eaten. When a pair is the plan, introduce both individuals at the same time so neither establishes territory first, and provide enough cave structure that each has a retreat.

In reef systems this species is best described as reef safe with caution. It shows no interest in corals and can be maintained in coral-stocked displays, but small shrimp, crabs, snails, and other diminutive invertebrates are treated as food. Keepers who prize an ornamental shrimp collection or a population of tiny gobies and dartfish should choose a different centerpiece. Housed with larger, appropriately assertive fishes and durable cleanup crew members, the Arrowhead Basslet becomes a striking and manageable addition to a mature reef.

FAQ

Frequently Asked Questions

About the Arrowhead Basslet

  • How big of a tank does an Arrowhead Basslet need?
    A single adult should be housed in at least a 75-gallon aquarium with open swimming space and cave-filled rockwork. A pair calls for considerably more volume, in the range of 125 to 140 gallons.
  • Is the Arrowhead Basslet reef safe?
    It is reef safe with caution. Corals are ignored, but small shrimp, crabs, snails, and small peaceful fishes may be eaten by this large-mouthed predator.
  • What should I feed an Arrowhead Basslet?
    Offer a varied carnivore diet of frozen or live mysis and brine shrimp plus chopped seafood such as shrimp, scallops, clams, squid, and fish flesh. Most specimens feed aggressively once acclimated.