Arc Eye Hawkfish - Paracirrhites arcatus

Arc Eye Hawkfish are highly likely to prey on ornamental shrimp (cleaner shrimp, peppermint shrimp, sexy shrimp) and very small crabs, especially once the hawkfish is settled and confident in the tank. Their hunting style is to perch and watch, then dart quickly at moving invertebrates. While some hobbyists report temporary success with larger, established cleaner shrimp in big tanks (90+ gallons with lots of rock), long-term survival of shrimp is unreliable. If you want to keep shrimp and crabs as display animals rather than food, it is best to avoid Arc Eye Hawkfish or accept that losses are very possible. Snails, urchins, and larger crabs are generally much safer.

Arc Eye Hawkfish strongly prefer a tank with complex rock structures and multiple “step-like” levels where they can perch and watch the tank. They are not big swimmers; instead, they hop from perch to perch. A minimum of several solid ledges at different heights, plus a main vantage point near the center-front of the tank, will help them feel secure and display natural behavior. If the rock structure is too sparse or flat, the fish can become more skittish, hide more often, and may channel its energy into increased aggression toward tankmates. Caves and overhangs are helpful so they can retreat quickly. In nano systems, vertical rock stacks with at least 3–4 distinct perching spots are ideal.

Arc Eye Hawkfish keep their overall orange-red body and distinctive blue “arc” through the eye, but their coloration can dull slightly at night or when startled, appearing more brownish or muted. A healthy fish will: perch upright with fins spread normally, show interest in food, and frequently scan the surroundings. Signs of stress include clamped fins, breathing rapidly while staying in one spot, very pale body color, or staying hidden for long periods even when food is added. If the arc marking and body stripes look noticeably faded during normal lighting hours, check for bullying tankmates, sudden lighting changes, poor water quality (especially elevated ammonia or nitrite), or lack of suitable perches making it feel exposed.

Arc Eye Hawkfish are carnivores and do best on a varied diet of small meaty foods: mysis shrimp, finely chopped krill, marine fish flesh, enriched brine shrimp, and quality marine carnivore pellets. Feed small portions 1–2 times daily; they are opportunistic and will overeat if you allow. To reduce aggression during feeding, use a turkey baster or target-feeding tool to spread food around the tank, so other fish get some first, then direct a portion toward the hawkfish’s perch. Avoid dropping all of the food in one spot, which trains the hawkfish to charge aggressively into the feeding area. Over several weeks, consistent feeding at the same time and location teaches it to wait in its usual perch instead of harassing more timid tankmates.

Arc Eye Hawkfish can be territorial, especially once they have claimed a favorite perch and have been established in the tank for a while. They are most likely to harass similarly sized, perch-loving fish (small gobies, blennies, and other hawkfish) and very passive species. To introduce new fish more safely, rearrange a portion of the rockwork right before adding the newcomer so territories are “reset.” Use an acclimation box or clear breeder box to float the new fish inside the display for a day or two; this lets both fish see each other while protected. Feed lightly near the box to create a positive association. If the Arc Eye spends all its time flaring and lunging at the box, extend the acclimation period and consider more rockwork changes. Once released, closely monitor interactions for a few days. Very persistent, damaging aggression may require removing the hawkfish and reintroducing it last.