Abstract Shallow lowland lakes are critical components of the water cycle, providing an essential service function. However, the impacts of microcystin from phytoplankton communities on benthic macroinvertebrate community diversity and structure have seldom been investigated. During 2008-2012, the impacts of water environmental variables on the diversity of macrobenthic communities, including water temperature, pH, dissolved oxygen, transparency, conductivity, the permanganate index, Chlorophyll a, total phosphorus, total nitrogen, and microcystin-LR (L for leucine and R for arginine), were measured in a typical shallow lowland lake, Ge Lake. The results of the present study demonstrated that there were 31 benthic macroinvertebrate taxa in Ge Lake, including 7 oligochaetes, 7 Mollusca, 14 chironomids, and 3 other taxa. Among the macrobenthic taxa in the benthic community, opportunistic taxa such as Limnodrilus hoffmeisteri are present and can occur at greater densities in disturbed habitats. However, a significant reduction/disappearance of sensitive and clean taxa was observed among the benthic macroinvertebrates. Water temperature, dissolved oxygen, conductivity, ammonia nitrogen, transparency and total phosphorus were the main environmental variables influencing macrobenthic community structure, while water temperature, conductivity, ammonia nitrogen, Chlorophyll a, the permanganate index, total phosphorus and total nitrogen were the main factors that influenced macrobenthic community diversity indices (the numbers of taxa, Shannon’s diversity index, Margalef’s richness index, and Pielou’s evenness index). Our results underscore the severity of the effects of human activity on Ge Lake and strongly suggest that restoring the benthic invertebrate community to previous conditions would require the control and reduction of environmental pollutants and nutrients in Ge Lake.

The immunological effect and preliminary molecular mechanism of lipopolysaccharide (LPS) on Malabar grouper (Epinephelus malabaricus) were studied. The grouper was injected intraperitoneally twice (7 days apart) with 4 mg kg-1 body weight of LPS from Escherichia coli (test group; testers) or pH 7.2 phosphate buffer solution (control group; drivers). Twenty-eight days later, the mean antibacterial, lysozyme and polyphenol oxidase activities of the serum showed tester values of 0.228, 0.032 and 21.8 U/mlxmin respectively, and driver values of 0.200, 0.015 and 15.5 U/mlxmin. A subtracted cDNA library from the head kidney of LPS-stimulated Malabar grouper was constructed using suppression subtractive hybridization. A total of 376 clones from tester-specific expressed gene fragments were selected and sequenced, and 326 qualified expressed sequence tags (ESTs) were obtained. After searching with the BLASTn and BLASTx programs, 312 ESTs showed great similarity for 13 gene fragments (14 ESTs did not match any genes in the Genbank). Out of these 13 fragments two (15.4%) were related to immune defense (interferon regulatory factor 2-binding protein 2-A and T-complex protein 1-theta); five (38.5%) were related to transcription or translation; one (7.7%) was involved in metabolism (CT054 protein); two (15.4%) might encode myeloid leukemia differentiation protein homologue and G patch domain-containing protein 3; and three (23.1%) were oxygen transport genes that encode haemoglobin α chain, haemoglobin β chain and ferritin heavy chain. Results showed that LPS could significantly improve innate immunity and regulate the expression of genes related to immunity, cellular energy production, growth, metabolism and/or stress-resistance in Malabar grouper. Also, LPS could be used as an effective immunostimulant for this species and provided an insight to the mechanisms of the effects of LPS on aquatic animals at serological and molecular levels.

Se estudiaron los efectos inmunológicos y el mecanismo molecular preliminar de lipopolisacáridos (LPS) en el mero malabárico (Epinephelus malabaricus). El mero se inyectó intraperitonealmente dos veces (con 7 días de diferencia) con 4 mg/kg-1 peso corporal de LPS provenientes de Escherichia coli (grupo de prueba, probadores) o solución de tampón fosfato pH 7,2 (grupo control, conductores). Veintiocho días después, la actividad media de antibacterianos, lisozima y polifenol oxidasa del suero mostraron valores de probador de 0,228, 0,032 y 21,8 U/ml x min, respectivamente, mientras que los valores de controlador fueron 0,200, 0,015 y 15,5 U/ml x min. Se elaboró una librería subtractiva de cDNA del riñón cefálico estimulado con LPS de mero malabárico utilizando hibridación substractiva por supresión. Se seleccionaron y secuenciaron 376 clones de fragmentos de genes expresados de probadores específicos, y se obtuvieron 326 EST calificados. Después de una búsqueda con los programas BLASTn y BLASTx, 312 ESTs mostraron gran similitud para 13 fragmentos de genes (14 ESTs no se asemejaron a ninguno de los genes en el GenBank). De los 13 fragmentos, dos (15,4%) estaban relacionados con inmunodefensa (factor 2 regulador de interferón-proteína de unión 2-A y complejo T de proteínas 1-theta); cinco (38,5%) estuvieron relacionados con la transcripción o la traducción; uno (7,7%) estuvo involucrado en el metabolismo (proteína CT054); dos (15,4%) codificarían homologoproteína de diferenciación, leucemia mieloide y la proteína 3 que contiene el dominio parche G; y tres (23,1%) eran genes de transporte de oxígeno que codifican la cadena α de hemoglobina, la cadena β de la hemoglobina y de la cadena pesada de ferritina. Los resultados mostraron que LPS podrían mejorar significativamente la inmunidad innata y regular la expresión de genes relacionados con la inmunidad, la producción de energía celular, el crecimiento, metabolismo o la resistencia al estrés en mero malabárico. Además, LPS pueden ser utilizados como un inmunoestimulante eficaz para esta especie, proporcionando una visión de los mecanismos de los efectos de LPS en animales acuáticos a niveles serológicos y moleculares.

To effectively control and treat river water pollution, it is very critical to establish a water quality prediction system. Combined Principal Component Analysis (PCA), Genetic Algorithm (GA) and Back Propagation Neural Network (BPNN), a hybrid intelligent algorithm is designed to predict river water quality. Firstly, PCA is used to reduce data dimensionality. 23 water quality index factors can be compressed into 15 aggregative indices. PCA improved effectively the training speed of follow-up algorithms. Then, GA optimizes the parameters of BPNN. The average prediction rates of non-polluted and polluted water quality are 88.9% and 93.1% respectively, the global prediction rate is approximately 91%. The water quality prediction system based on the combination of Neural Networks and Genetic Algorithms can accurately predict water quality and provide useful support for realtime early warning systems.