Extender for Sperm Dilution in Olive Ridley Turtle (Lepidochelys olivacea) and Hawksbill Turtle (Eretmochelys imbricata) Semen

Abstract

The objective of the study was to find an extender to dilute and preserve sea turtle semen. Six adult olive ridley turtles (Lepidochelys olivacea), and 4 adult hawksbill turtles (Eretmochelys imbricata) from Phuket Marine Biological Center and Eastern Marine and Coastal Resources Research Center in Thailand had semen collected using electroejaculator. The study was repeated twice in 2007 and 2008. After collection, each semen sample was divided and preserved in 8 different extenders, which were 1) refrigeration medium test yolk buffer, 2) Tyrode medium supplemented with albumin, lactate and pyruvate, 3) Beltsville poultry semen extender, 4) 3% Sodium citrate buffer, 5) Phosphatebuffered solution, 6) EEL extender, 7) 1% bovine serum albumin, and 8) HAM F-10 and kept at 4℃ and evaluated for viability (motile sperm) at 0, 0.25, 0.5, 1, 3, 6, 12, 24 and 48 hours. The results found that for 28% olive ridley turtles and 25% hawksbill turtles that their spermatozoa diluted in extender 1, and for 14% of both sea turtles that their spermatozoa diluted in extender 2 could survive for 24 hours. However, the motility from both sea turtles semen in both extenders was decreased by 50-80 %. Most sperm died after being diluted in the last 6 extenders. By conclusion, extender 1 and 2 were suitable extenders for sea turtle semen viability, however, adding other ingredients should be considered to enhance in viability.