Resumen

BASTARDO, Hilda; GUEDEZ, Carlina  y  LEON, María. Características del semen de trucha arcoiris de diferentes edades, bajo condiciones de cultivo en Mérida, Venezuela. Zootecnia Trop. [online]. 2004, vol.22, n.3, pp.277-288. ISSN 0798-7269.

The female and male of the rainbow trout have different maturity age of the gonads; the female maturation is at two years old, while the mature age male is at one year old. The objective of this research was to study some semen characteristics of the rainbow trout related to age. We evaluated two, three, four, and five years old male trouts. A sample of ten trouts of different age were weighted and some macroscopic and microscopic semen characteristics were observed. The semen volume of the two year old trout was significantly smaller than that of three, four, and five year old trouts. Spermatocrit of the two and three year old trout were similar and significantly higher than the five year old trout. We observed a lineal relationship between spermatocrit and sperm concentration (r=0.648). Sperm concentration of the two year old trout were significantly higher than three, four, and five years old trouts (4.341 x 109 on four year old, and 9.978 x 109 spermatozoid/mL on two year old trout). Spermatozoids with normal head increased from two year old to four year old trout, and then declined in abrupt way on five year old trout. Spermatic cells with amorphous head were significantly higher on five year old trout, and the ones with small and elongated head did not show significant difference among the different age groups.

Palabras clave : Trout; semen; sperm; reproduction.