Tosanoides bennetti is a diminutive deep-reef anthias that matures at roughly 2 inches. Males present a lavender-pink body crossed by four diagonal yellow bands, which may fragment into irregular spots, along with yellow accents on the dorsal, anal, and pelvic fins and elegant filamentous lobes on the caudal fin. Females are lavender-pink through the forward half and shift to yellow toward the rear, showing a yellow bar along the anal spines and a yellow-brown blotch on the dorsal fin. The species is known from the Coral Sea and New Caledonia, where it lives on deep mesophotic reefs, favoring rocky bottoms with coralline sediment and silt broken by fissures and crevices.

A trio calls for a mature, exceptionally stable system, and a 125-gallon aquarium gives the group the volume and buffering capacity this fish demands. Build abundant rockwork with caves and passages so the fish have both open swimming lanes and immediate shelter; substrate is optional. Strong filtration paired with moderate to strong flow keeps oxygen levels high, and the tank should be covered because startled individuals will bolt. This is a cool-water fish from the twilight zone, so the aquarium must be held in the upper 60s to low 70s Fahrenheit with very low nitrate and rock-steady chemistry.

Lighting deserves particular attention. Start the group under subdued illumination that echoes the dim conditions of their native depth, then step brightness up gradually over several weeks if the fish will ultimately share a brightly lit reef display. Given the cool temperature requirement, expert-level husbandry, and intolerance of swings, this species is best reserved for aquarists with a proven track record on demanding deepwater fish.

In the wild, Bennett's Anthias feeds chiefly on planktonic organisms drifting past the reef face, with some incidental algal material also reported. Replicate that with a rotation of small frozen and live items: mysis shrimp, enriched brine shrimp, and red plankton all suit the small mouth well. Round the menu out with nutritionally dense small pellets and an algae-containing preparation to cover the plant fraction of the diet.

These are busy, high-metabolism fish that burn through energy quickly, so plan on a minimum of three feedings each day. Training the trio to accept pellets is worth the effort, since an automatic feeder can then deliver small portions on schedule and keep body condition up without the aquarist standing over the tank. Watch each fish individually during feedings, as thin flanks are the first warning that the ration is insufficient.

Mysis Shrimp Enriched Brine Shrimp Red Plankton Small Marine Pellets Algae-Based Preparations
Bennett's Anthias is an active, peaceful planktivore that forms harems in nature, with a single dominant male overseeing several females. Keeping a trio or a larger group reflects that structure and produces the most natural behavior, with the fish hovering above the rock and darting back to cover when alarmed. Their small size and mild disposition mean they are easily intimidated, so quiet surroundings matter as much as water quality.

Choose calm tankmates that also thrive in cooler water, such as cardinalfishes, fairy wrasses, shrimp gobies, firefish, ocellaris clownfish, and other small, peaceful anthias. Boisterous or aggressive fish will outcompete the trio at feeding time and should be excluded. The species is reef safe and mixes well with corals, since its diet is planktonic rather than coral-based; available evidence does not specifically address safety with ornamental shrimp, crabs, snails, or clams, so observe any new mix of invertebrates rather than assuming an outcome.

FAQ

Frequently Asked Questions

About the Bennetti Anthias Trio

  • Is a Bennetti Anthias Trio suitable for a beginner?
    No. This deepwater species demands expert-level husbandry, a mature aquarium, cool and highly oxygenated water, frequent feeding, and exceptionally stable parameters.
  • How large should the aquarium be for a trio?
    Plan on a 125-gallon aquarium for a trio. Although the fish reach only about 2 inches, the added volume supports the stability and open swimming room this species requires.
  • Can Bennett's Anthias be kept in a reef aquarium?
    Yes, it is reef safe and compatible with corals, provided the other reef inhabitants tolerate its cooler preferred temperatures. Safety with shrimp, crabs, snails, and clams is not specifically documented.