The role of fatty acids enrichments in the larviculture of false percula clownfish Amphiprion ocellaris

At present, clownfishes are the best example of successfully captive bred ornamental specimens but little is known about the relationship between food enrichment and both larval growth and development. In fact, it is well known that a certain percentage of these fishes cultured in captive conditions show a miss-band pigmentation. In the present study, the effects of live prey enrichment on growth and pigmentation in false percula clownfish (Amphiprion ocellaris) larvae were tested. Newly hatched A. ocellaris larvae were divided in three different groups and fed as follows: group A fed on enriched (Algamac 2000) B. plicatilis (10 ind./mL) from day 1 to day 5 post-hatch (ph); group B fed on enriched (Algamac 2000) B. plicatilis (10 ind./mL) followed by Artemia nauplii (5 ind./mL;) and group C fed on Algamac 2000 enriched B. plicatilis and Algamac 2000 enriched Artemia nauplii. Samples of the larvae were collected on day 5 from group A and on day 11 ph in group B and C for morphometric and molecular analysis. On day 11 ph food enrichment resulted in a better growth of group C larvae respect to those of group B fed on not enriched Artemia nauplii (15.8 ± 0.2 mg and 8.78 ± 0.02 mm vs. 6.8 ± 0.2 mg and 6.93 ± 0.01 mm). Moreover, 36 ± 2% of the juveniles obtained from group B showed a miss-band pigmentation as compared to 29 ± 1% of the juveniles obtained from group C. At molecular level, the results obtained by Real-Time PCR are in agreement with the morphometric ones: a positive induction of the Insulin-like Growth Factor II (IGFII) and Peroxisome Proliferator Activated Receptor α and β (PPARα and PPARβ) gene expression and a reduction of Myostatin (MSTN) was observed in group C larvae fed on enriched live prey. IGFI gene expression was higher in group B. The present study provides clear evidences of the positive role of Algamac 2000 on growth and pigmentation of captive cultured false percula clownfish.