author(s)
Peralta M María de los Ángeles, Velasco S Javier and Retana O Diego Alberto

abstract
The sperm quality of the adult white fish Chirostoma estor was evaluated. The study was carried out over a period of 7 months (July 2014 to May 2015), at the facilities of the Regional Fisheries Research Center (CRIP-Pátzcuaro) Michoacán, Mexico. A total of 112 reproductive organisms of 24 months of age with a mean height and weight of 12.63±1.42 (cm) and 16.93±6.19 (g), respectively, were used. Mobility, viability and sperm concentration were determined. The results showed that the form of the spermatozoa of C. estor was cylindrical and uniflagellate. The highest recorded volume was 120 μL for the months of August and September and the lowest volume was recorded in the month of October with 41 μL. Additionally, the motility of the spermatozoa was a progressive forward movement with several movements from their flagellum for the months of April, May, October and November, but in July, 80-90% of the cells vibrated while others were immobile. With respect to viability, in all months it was 98-100% of live cells and the maximum sperm concentration was presented in the months of April and May with an average of 2.63 and 3.61 X 106 cells/μL, respectively.