Sperm biology of Merluccius australis: Sperm structure, semen characteristics and effects of pH, temperature and osmolality on sperm motility

Effer Roldan, Brian
Figueroa Villalobos, Elías
Augsburger, A.
Valdebenito Isler, Iván
Datos de publicación:
In this article we describe basic aspects of the sperm biology of Merluccius australis, in particular assessing the effects of pH (6, 8 and 10), temperature (4, 10 and 15 degrees C) and osmolality (922 mOsm/kg, 822 mOsm/kg, 681 mOsm/kg and 3 mOsm/kg) on sperm motility. Our results indicate the presence of semen with sperm density of 4.6 x 10(9) sp/ml which contains a primitive spermatozoon with total length 40.95 +/- 1.5 mu m, with no acrosomes and two mitochondria. Sperm motility is initiated on contact with a hyperosmotic swimming medium (SM), and under normal conditions (922 mOsm/kg, pH 8 and 14-15 degrees C) may last for up to 9.18 min; however a pH higher or lower than 8 has a negative effect on both motility and the percentage of motile cells (%MC). The longest motility period (696 s) was recorded at 4 degrees C; however, regardless of the temperatures assessed, a gradual decrease in motility was observed as the osmolality of the SM diminished, with immobility observed at 3 mOsm/kg. The information generated in this research will be useful for developing biotechnology tools for the effective management of M. australis gametes. (C) 2013 Elsevier B.V. All rights reserved.