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San Lorenzo Vista Hermosa, Mexico

Melgar Valdes C.E.,Colegio de Mexico | Melgar Valdes C.E.,Juarez Autonomous University of Tabasco | Macias E.B.,Colegio de Mexico | Alvarez-Gonzalez C.A.,Laboratorio Of Acuicultura Tropical | And 2 more authors.
Revista de Biologia Tropical | Year: 2013

Microorganisms effect with probiotic potential in water quality and growth of the shrimp Litopenaeus vannamei (Decapoda: Penaeidae) in intensive culture. The use of probiotics has gained acceptance in aquaculture, particularly in maintaining water quality and enhancing growth in organisms. This study analyzed the effect of the commercial (EM™, Japan) natural product composed by (Rhodopseudomonas palus-tris, Lactobacillus plantarum, Lactobacillus casei and Saccharomyces cerevisiae) added to the water, in order to determine its effect in water quality, sediment and growth of L. vannamei under intensive culture. The evaluation included three treatments with a weekly addition of EM: i) tanks without probiotics (C), ii) tanks with a dose of 4L/ha (EM1) and iii) tanks with a dose of 10L/ha (EM2). The treatment C was carried out three times, while treatments EM1 and EM2 were carried out four times. A total of 4 350 shrimps were measured for total length and weight, to calculate total and porcentual weight gain, daily weight gain, specific growth rate (TCE), and food conversion factor (FCA); besides, the survival rate was estimated. The use of probiotics allowed a shorter harvest time in treatments EM1 (90d) and EM2 (105d) with relation to the treatment C (120d). Treatments EM1 and EM2 were within the recommended intervals for culture, with respect to treatment C. The use of probiotic bacteria significantly regulated pH (EM1, 8.03±0.33; EM2, 7.77±0.22; C, 9.08±0.35) and reduced nitrate concentration (EM1, 0.64±0.25mg/L; EM2, 0.39±0.26mg/L; C, 0.71mg/L). Water pH mostly explained the variance with respect to the treatments. Treatment EM2 presented the greatest removal of organic matter (1.77±0.45%), whereas the contents of extractable phosphorus increased significantly in treatment EM1 with 21.6±7.99mg/kg and in treatment EM2 with 21.6±8.45mg/kg with control relation (14.3±5.47). The shrimp growth was influenced by dissolved oxygen, salinity and pH in the sediment, establishing that salinity was the most important variable in the weight with a negative association. Treatment EM1 recorded an improved TCE (2.69±0.35%/d) and FCA (1.46±0.20) with relation to the control treatment (TCE, 1.88±0.25%/d; FCA, 2.13±0.48). Survival was significantly greater in treatments containing probiotics with 61±8.76% and 60±10.5% for EM1 and EM2, respectively. This study indicated the positive effect obtained with the use of this commercial probiotic, to improve culture conditions and growth parameters in an intensive culture of L. vannamei. Source


De Oliveira F.H.P.C.,Laboratorio Of Hidrobiologia | Ara A.L.S.C.E.,Federal Rural University of Pernambuco | Moreira C.H.P.,Federal Rural University of Pernambuco | Lira O.O.,Laboratorio Of Controle Da Qualidade Da Agua | And 2 more authors.
Anais da Academia Brasileira de Ciencias | Year: 2014

This study investigated the water quality in an urban eutrophic reservoir in Northeastern Brazil, considering the influence of seasonality. Monthly, samples were collected in the sub-surface reservoir. The following abiotic variables were analyzed: temperature, pH, dissolved oxygen, apparent color, turbidity, conductivity, fluoride, total nitrogen, chlorides, total dissolved solids, total hardness, iron, copper, manganese, aluminum, chlorophyll-a and phaeophytin. Total and thermotolerant coliforms were analyzed according to APHA (2012). Cyanobacteria density was quantified through its biomass. The data were analyzed using one- way ANOVA and Pearson correlation test. Higher values mean phytoplankton biomass (26.3mm3.L-1) occurred in the dry season, especially Planktothrix agardhii and Geiterinema amphibium, which occurred in 100% of samples. High trophic state index was detected throughout the year. Seasonality exerted some influence on both biotic and abiotc variables, leading to changes in water quality of the reservoir. © 2014 Academia Brasileira de Ciencias. All Rights reserved. Source


Macossay-Cortez A.,Laboratorio Of Hidrobiologia | Sanchez A.J.,Laboratorio Of Hidrobiologia | Florido R.,Laboratorio Of Hidrobiologia | Huidobro L.,National Autonomous University of Mexico | Montalvo-Urgel H.,Laboratorio Of Hidrobiologia
Acta Ichthyologica et Piscatoria | Year: 2011

Background. Thirty species were previously recorded for unstructured habitats (unvegetated soft substrates: USS) in Pantanos de Centla. However, a lack of information on the tropical ichthyofauna of the structured habitats such as marginal vegetation (MV), submerged macrophytes (SM) and coarse woody debris (CWD) emphasizes the importance of the aim of this paper that is the updating the records of the species distributed in these habitats, as they have been frequently reported as high biodiversity sites that are currently threatened by anthro- pogenic activities. Materials and methods. Sampling was carried out in 30 shallow sites, each with unstructured habitats and the three structured habitats, in Pantanos de Centla, a Ramsar wetland, over a period of three years. Fish were collected with a dip net, a drop net and a Renfro beam net. Results. A total of 6506 fish of 37 genera and 44 species were collected. Eleven species are new records for Pantanos de Centla, and the scientific name of 11 species was updated. The Poeciliidae and Cichlidae families are dominant with 10 and 13 species, respectively. Nine species of the genus Cichlasoma sensu lato were placed in six genera. Three species are new records for the Usumacinta Province. Ctenogobius claytoni, Gobionellus oceanicus, and Rhamdia quelen proved to be synonyms. Of all species, 84% were collected from USS, however, the number of species distributed in USS, MV, and SM was similar (CC j 0.4736-0.5813). Conclusion. Most of the species that were added to the previously recorded species list of Pantanos de Centla, inhabit structured habitats. This confirms the importance of including these habitats in surveys aimed at generating checklists, and of analysing the distribution of fish species in shallow tropical ecosystems. Source

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