Category Archives: Fisheries

“Fatty acids of wild and cultured Penaeus vannamei larvae from Ecuador” (Motano & Navarro 1996)

Citation: Montano, M., and Navarro, J. (1996). “Fatty acids of wild and cultured Penaeus vannamei larvae from Ecuador.” Aquaculture, 142, pp. 259-268.

Summary by: Alexandra Pounds

Image Credit: Wikimedia Commons

  • Big Picture: Wild larvae are more resilient than cultured larvae fed on artemia, probably because wild larvae have diets that have higher levels of long-chain PUFA.
  • Wild postlarvae are more resilient than cultured. Wild caught larvae have higher survival rates. In fish, resilience is associated with higher levels of omega-3 PUFA (poly-unsaturated fatty acids), mainly, EPA and DHA. This study asked if it was the same with shrimp.
  • Methods:
    • Larvae were collected from 5 sites along the coast of Ecuador throughout the summer. Larvae from the hatchery were also collected. This resulted in three separate groups:
      • Cultured larvae
      • Early summer (cold) wild larvae
      • Late summer (hot) wild larvae
    • The researchers extracted lipids from these larvae for analysis.
  • Results:
    • Wild larvae from the colder months had significantly higher DHA, EPA, and 16:1 levels.  Wild larvae from the warmer months had significantly higher saturates and 18:2 omega-6 PUFA.
    • There were no differences in arachidonic acid, monoenes, 18:3 omega-3, and the ratio of DHA to EPA (DHA:EPA) over the different months.
    • Wild larvae had significantly higher levels of EPA, DHA, 16:0, 16:1, 18:0, DHA:EPA, and saturated fatty acids than cultured larvae.
    • Cultured larvae had higher levels of 18:3 omega-3, 20:4 omega-6, 18:2 omega-6, 18:1, and monoenes.
    • Origin of wild larvae had no effect on lipids.
  • Implications:
    • Higher temperatures cause higher levels of saturated fatty acids, whereas colder temperatures cause higher levels of unsaturated fatty acids.
    • Wild larvae had higher levels of PUFAs than cultured, probably due to diet. Cultured larvae are fed enriched artemia, which has more linolenic acid. Linolenic acid was 15 times higher in cultured larvae than wild larvae.
    • The results suggest that, as in fish, shrimp larvae that are cultured with artemia and have lower levels of long-chain PUFAs are less resilient.