RESUMO
Anoxic sediments favor sulfate reducing bacteria proliferation, main characteristic of reduced environments, which are used for crustaceous culture. In Mexico, it has been reported the presence of anoxic sediments in the channels of Xochimilco, reduced environment that could be used for culture of organisms, like crayfish (Cambarellus montezumae). The aim of this study was to prove that reduced environments can be used for the production of culture susceptible aquatic organisms for human consumption. Apatlaco and Cuemanco channels are characterized as reduced environments, its water and sediment physicochemical parameters were evaluated; heavy metals in sediment and organisms were assessed; presence and sanitary quality of crayfish was proven, through qualitative and quantitative analysis of its bacteria charge; nutritional quality of crayfish was determined, by proximal chemical analysis. It was proven that the channels of Xochimilco fulfill the reduced environment characteristics, presence of crayfish C. montezumae in these channels was verified, it was shown that the levels of heavy metals and bacteria charge recorded, do not exceed the maximum allowed limits for edible crustaceous, important protein source for human consumption. Based on the previous, it is affirmed that reduced environments can be used for culture of edible aquatic species.
Los sedimentos anóxicos propician proliferación de bacterias sulfato-reductoras, característica principal de los ambientes reducidos, que se aprovechan para el cultivo de crustáceos. En México se ha notificado presencia de sedimentos anóxicos en los canales de Xochimilco, ambiente reducido, que podrían aprovecharse para el cultivo de organismos, como el acocil (Cambarellus montezumae). El objetivo del presente estudio fue probar que los ambientes reducidos pueden ser útiles para la producción de organismos acuáticos susceptibles de cultivo, y además, para consumo humano. Se caracterizaron los canales Apatlaco y Cuemanco como ambientes reducidos, se evaluaron parámetros fisicoquímicos del agua y sedimento; se determinaron metales pesados en sedimento y organismo; se comprobó la presencia y calidad sanitaria del acocil, a través de los análisis cualitativo y cuantitativo de su carga bacteriana; se determinó la calidad nutrimental de los acociles por medio de análisis químico proximal. Se probó que los canales de Xochimilco cumplen con las características de ambiente reducido, en el que se comprobó presencia del acocil (C. montezumae). Se demostró que los niveles de metales pesados y carga bacteriana registrados no superan los límites máximos permisibles para crustáceos comestibles, fuente importante de proteínas para el consumo humano. Con base en lo anterior se afirma que los ambientes reducidos pueden ser aprovechados para el cultivo de especies acuáticas comestibles.
RESUMO
In this paper is presented the percentage of fatty acids composition of three Artemia franciscana Mexican populations of epicontinentals waters; two are from natural environments (Coahuila and San Luis Potosf) and one (Texcoco) is a culture fed with Spirulina. Determination of fatty acids composition in each population, was performed by extraction of total lipid by the soxhlet method and the fatty acids methyl esters were determined by gas chromatography. The results show that Artemia of Texcoco contains the six fatty acids recommended for the culture of fish and crustaceans (16:0; 16:1; 18:1; 18:2w6; 18:3w3 and 20:5w3); Artemia from San Luis Potosi showed the poorest content in these acids and Artemia from Coahuila, although it showed a wide profile, it lacks the linolenic acid. When comparing results among the three populations with ecological data that have been published, it can be pointed out that the environment is decisive for this crustacean; Artemia from Texcoco fed with Spirulina showed the largest variety of fatty acids; the other two populations are wild, and lives in different habitats, Artemia of Coahuila is found in waters that are rich in sulfates and Artemia of San Luis Potosf lives in evaporation saltern ponds, built with stone blocks and therefore with scarce phytoplankton growth. Both Artemia populations showed deficiencies in essential fatty acids, mainly the last one.
