EVALUATION OF GENETIC VARIABILITY OF THREE LINES OF Cherax quadricarinatus CULTURED IN MEXICO.

Pedro Cruz*, Humberto Villarreal, José Naranjo & Mayra Vargas.
 
Aquaculture Program
Centro de Investigaciones Biológicas del Noroeste S.C.
 Instituto Politécnico Nacional 197. Playa Palo de Santa Rita. 23090
La Paz, Baja California Sur, México.
pcruz@cibnor.mx

Commercial culture of Cherax quadricarinatus in Mexico has been considered an alternative to diversify aquaculture production since first introductions of the species by the federal government in the 90's. CIBNOR, one of the leading institutions on redclaw research in the world, reported in 2008 advances on an award winning eco-efficient system for intensive culture of redclaw. The technology reduces energy consumption, improves feed conversion rates, optimizes water use and significantly reduces the cost of production whit yields of 5000 kg/Ha. A limitation, however, has been the time required to achieve commercial size. On the other hand, most farms restock breeding ponds directly from grow out ponds. This has generated a growing concern about the potential reduction in harvest size and performance, due to inbreeding over time. Furthermore, the implementation of genetic selection programs will contribute to consolidate the development of a redclaw culture industry in Mexico.

The objective in this study was to determine the level of variability and genetic differentiation from three lines of C. quadricarinatus, obtained from commercial farms in the Mexican states of Tamaulipas, Michoacan and Baja California Sur.  DNA extraction and microsatellite amplification by PCR were performed, before electrophoresis with polyacrylamide gels. The number of alleles per loci was estimated according to the principles of Hardy-Weinberg equilibrium. From the analysis, a strategy to increase variability in the rearing stocks was developed as the first step towards establishing a family based selection program for genetic improvement. Advances and results are discussed.