Aspectos limnológicos de estanques para la producción intensiva de tenca (Tinea tinea)

Abstract

Tench is considered a slow growing species in comparison with other ciprinids, even though high zooplancton densities in intensive farms significantly improve juvenile growth. In order to better study the which factors are important on trench production under semi-intensive conditions, an experiment was carried out, in nine triplicates pools combining different fertilizers (natural manure or nitrates) (3 inorganic pools, 3 organic pools and 3 control pools). From July to September 2003, fortnightly samples were taken from physical-chemical and Zooplankton to test the effect of the experimental conditions over those variables. From the study, a total of 57 taxa were identified: 6 copepoda, 18 cladocerans and 33 rotifers. Total Zooplankton abundance was higher in the fertilized treatments than in the control, the differences being significant in the inorganic treatment, which indicates a positive effect of the increment in the nutrient load over the zooplanktic communities. Even though no significant differences were observed among inorganic and organic fertilizers, the biomass was slightly superior in the inorganic treatment. The faunistic composition in both treatments was similar. The Zooplankton community was dominated by rotifers, small cladocerans, and nauplii the latter being an important fraction of the community. © Asociación Española de Limnología.