The flame hawkfish (Neocirrhites 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 behavior . C aptive rearing of hawkfish is of great interest but is limited by broodstock spawning and defined larviculture protocols . Fertilized embryos yield altricial larvae lacking functional eyes, mouth, and digestive tract, and are thus dependent on endogenous yolk reserves until first feeding . Th e transition stage from endogenous to exogenous feeding is defined by mass larval mortality due in part to lack of appropriate nutrition. Mortality can be reduced through manipulations of environmental conditions that increase prey capture and promote growth and survival. These conditions are species-specific, and development of such protocols will facilitate culture efforts and promote commercialization of the flame hawkfish.
Initial larval rearing experiments with N. armatus evaluated the effects of algae density, algae species, copepod species, copepod density, and prey type on the survival, growth, and feeding incidence from 0 – 5 days post hatch (DPH) . The greatest survival and feeding incidence for algal density was 150,000 cells mL-1 of Tisochrysis lutea . The comparison of algal species showed a significant increase in survival using Nannochloropsis oculata over T. lutea, with no significant difference in feeding incidence (Figure 1). Larvae fed on Parvocalanus crassirostris showed no significant difference in survival and feeding incidence over those fed Oithona colcarva . Using these results, rotifers were introduced at first feeding in comparison and alongside copepods as a 50/50 mix. This experiment indicated that larvae cannot consume rotifers at first feeding and still do not ingest them at 5 DPH , resulting in the highest survival and feeding incidence in the copepod only treatment. The prey density experiment compared densities ranging from 1.25 – 5.0 nauplii/mL per day. While initial feeding incidence was significantly greater in the 5.0 copepods mL-1 treatment, there was significantly higher survival in the 1.25 and 2.5 copepods mL-1 treatments , with significantly greater growth in the 2.5 and 5.0 copepods mL-1 treatments . The development of early larviculture protocols for N. armatus will provide critical information necessary for commercialization of this species.