The flame hawkfish (Neocirrhitus armatus) is a marine ornamental fish endemic to the Indo-Pacific and is popular in the aquarium trade due to its bright coloration, small size, and charisma. Due to their popularity, captive rearing of hawkfish is of great interest, but is limited by difficulties in broodstock spawning and a lack of larval rearing data. Natural spawning of N. armatus began in June 2022 and several attempts have been made to rear the larvae to the juvenile stage. The larvae take approximately 24 hours to hatch at 27°C and are 2 mm in length (TL). At hatching, larvae lack functional eyes, mouth, and digestive tract, thus are dependent on endogenous yolk reserves. The stage of “first-feeding”, where endogenous reserves are exhausted and the larvae must switch to exogenous feeding, is critical for development and survival. Mass larval mortality is common during this period from lack of appropriate nutrition. N. armatus larvae reach this critical period at 3 days post hatch (DPH) at a length of approximately 3 mm (TL). Attempts to rear these larvae have been successful until 12 DPH, with significant mortality at 10 DPH. Mortality at this developmental stage could be due to other developmental bottlenecks, such as swim bladder inflation, which occurs at approximately 7 DPH, or the beginning of notochord flexion, which occurs at approximately 9 DPH.
There is no current information on the larval rearing of N. armatus and initial experiments will test the effects of environmental conditions on survival, growth, and feeding incidence from 0 – 5 DPH. Experiments evaluating the effects of algal density are currently underway using densities of 0 – 600,000 cells mL-1of Tisochrysis lutea. Other environmental conditions of interest include algae species, copepod species, copepod density, and prey type. These experiments will all focus on improving survival at the first feeding bottleneck, and later experiments may focus on bottlenecks in production at 10 DPH. The development of early larviculture protocols for N. armatus will provide critical information necessary for commercialization of this species.