The Ocellaris clownfish (Amphiprion ocellaris) has been a staple aquaculture species since the 1970s and has increased in popularity since the development of designer varieties and the release of ‘Finding Nemo’. Clownfish are also increasingly used as a model organism for ecological, developmental, and evolutionary biology studies. However, production is still impacted through bottlenecks during larviculture resulting in reduced survival and increased incidence of undesirable deformities. Because of the widespread popularity of this species both as an ornamental and model organism, improvements in larviculture efficiency and the development of a standard protocol could broadly benefit the marine ornamental trade and research.
To evaluate the influence of culture parameters on larval performance of clownfish, experiments manipulating green water product type and density, stocking density, copepod species, copepod replacement of standard live feeds, rotifer enrichment, and Artemia enrichment were conducted until 10 – 25 days post hatch (DPH). There was also a final combined trial, comparing successful treatments with reference protocols obtained from producers. Results from the green water product experiment found that a treatment containing Nannochloropsis spp. (RotiGreen® Omega) yielded higher survival than Tisochrysis spp. and no-algae controls, with no differences found in growth. This green water was evaluated at three different densities for changes in survival and growth; however, no differences were observed among treatments. A stocking density trial tested three densities, with the highest showing reduced survival and growth. In the copepod type study, larvae were reared with a diet of either Oithona colcarva, Parvocalanus crassirostris, or a 50/50 mixture of both. P. crassirostris resulted in higher survival, although no differences in growth were observed. A subsequent trial replacing rotifers or Artemia with copepods was completed, although no differences in survival or growth were observed. A rotifer enrichment experiment found the greatest survival with Algamac 3050® and no differences in growth. Next, three different enrichments v. unenriched Artemia were tested, with no differences in survival or growth among groups. Finally, in the combined experiment, treatment protocols had ≈200% higher survival than reference protocols (Figure 1). Together, these data will help to create standardized larviculture recommendations to help production and research thrive