THE EFFECT OF DIFFERENT LIVE FEEDS ON THE LARVICULTURE OF SEXY DANCER SHRIMP Thor amboinensis

The main bottleneck in marine ornamental shrimp aquaculture remains in the larviculture. Larval nutrition plays a key role on survival and development during this phase. The Thor amboinensis (De Mann 1888), commonly known as sexy dancer shrimp, is a very popular species in the marine ornamental market, due to its bright coloration, unusual body movements and associative behavior with several species of anemones and corals. The objective of this study was to identify appropriate prey items to improve larval quality and shorten larval duration of the sexy dancer shrimp.

A 25-day feeding trial was conducted to examine the influence of five different fed regimes and control, T0-Starving larvae; T1-Isochrysis sp. concentrate at 1.000.000 cells/mL; T2- Thalassiosira pseudonana concentrate at 250.000 cells/mL; T3- Enriched Artemia salina at 5/mL; T4- Enriched rotifers B. rotundiformis at 30/mL; T5- copepodites Apocyclops panamensis at 15/mL on larval survival and development during the eight zoea stages of the larval development of the T. amboinensis shrimp. Three hundred twenty four newly-hatched vigorous larvae were collected from the spawning tank and divided equally (18 larvae) into eighteen 1-L glass beakers (filled with 900 mL of salt water at 35 ppt) at a density of 20 larvae/L, immersed in a water bath (27°C). Moderate aeration was provided. A 70% water change was performed daily followed by the addition of the live prey or microalgae concentrate maintaining the same food density.

Despite been considered mainly carnivorous by many authors, zoea fed exclusively with micro algae  survived considerably longer than zoea fed with copepodites and starved treatment, reaching the zoea V stage. After 25 days, survival of  larvae fed with enriched rotifers (48.15 ± 9.26%) was significantly higher compared to the ones fed with enriched Artemia (18.51 ± 3.72%). A small percentage (7.69%) of larvae fed with enriched rotifers were also able to settle by the end of the trial.  These results indicate that a diet based on enriched rotifers appears to be more suitable for the Thor amboinensis larviculture, and the presence of microalgae can have a positive impact on the quality of the larvae.