The effect of photoperiod on the reproduction of Chirostoma estor estor Jordan 1879 from Lago de Pátzcuaro, Mexico

Abstract

First paragraph: The Mexican silverside (Chirostoma estor estor) is one of a group of native Atherinopsid freshwater species endemic to the lakes of Central Mexico. C. estor estor is the principal species of the fishery in Lake Pa L tzcuaro where for many years it has provided a subsistence income for a large number of families. It is a high-value species that has become endangered because of pollution, introduction of exotic species and through over-fishing (Martınez-Palacios et al., 2002, 2004). It has great potential for aquaculture and in recent years there has been increased interest in its culture. The development of native species requires comprehensive control of their reproductive cycle. C. estor estor is able to spawn throughout the year given the proper circumstances, but its reproductive peak in the wild is from February to July. In many species it is very advantageous to be able to manipulate the reproductive activity of broodstock to improve egg and sperm production (Bromage et al., 2001). This may enable continuous yearround production of fry without dependence upon the natural environment.