Optimization of Triploidy Induction in the Pacific White Shrimp, Litopenaeus vannamei

Abstract

We describe the results of the optimization process to induce triploidy in the Pacific white shrimp, Litopenaeus vannamei, reported the diploid and triploid chromosome numbers, the time of the extrusion of the second polar body and the survival rate at the nauplii larvae stage. The diploid chromosome number was 88 (42.5%). The extrusion of the second polar body was observed in eggs within 16 and 20 minutes post-spawning, the higher frequency occurred at 18 minutes. The triploid chromosome condition was induced by application of cold shock (10°C) to eggs 20 minutes after fertilization and with a duration of 15 minutes. We obtained a high eclosion rate (79%) in comparison to other studies. The verification of triploid nauplii larvae in mitotic metaphase showed a chromosome number set of 132.

Key Words:

• Triploidy
• Litopenaeus vannamei
• chromosome
• polar body
• nauplii