Biology and use of the Pacific fat sleeper Dormitator latifrons (Richardson, 1844): state of the art review

The present work is a review of the literature on the native Mexican fish Dormitator latifrons. The aim is to contribute to the integration and systematization of current knowledge to make it easier to identify existing knowledge gaps and breakthroghs Moreover, promote the successful cultivation and protection of this species whose consumption is increasing in Latin America. A review of the articles related to D. latifrons published in international and regional databases was carried out. The articles reviewed focus on taxonomy and systematics, phylogenetic, geographic distribution, ecology, physiology, reproduction, development, pathology, health, and the technologies used to cultivate this fish species. The conclusion is that, even though the cultivation of D. latifrons is of commercial interest in some countries, there are still significant gaps in our knowledge of biology and, consequently, the domestication potential of the species. Filling these gaps will require systematic research efforts on protecting natural populations and improving mass cultivation techniques.Fil: Vega Villasante, Fernando. Universidad de Guadalajara; MéxicoFil: Ruiz González, Luis E.. Universidad de Guadalajara; MéxicoFil: Chong Carrillo, Olimpia. Universidad de Guadalajara; MéxicoFil: Basto Rosales, Mao E. R.. Tecnológico Nacional de Bahía de Banderas; MéxicoFil: Palma Cancino, David J.. Universidad de Guadalajara; MéxicoFil: Tintos Gómez, Adrián. Universidad Tecnológica de Manzanillo; MéxicoFil: Montoya Martínez, Cynthia E.. Universidad de Guadalajara; MéxicoFil: Kelly Gutiérrez, Liza D.. Universidad de Guadalajara; MéxicoFil: Guerrero Galván, Saúl R.. Universidad de Guadalajara; MéxicoFil: Ponce Palafox, Jesús T.. Universidad Autónoma de Nayarit; MéxicoFil: Zapata, Ana. Universidad de Guadalajara; MéxicoFil: Musin, Gabriela Eliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Badillo Zapata, Daniel. Universidad de Guadalajara; Méxic

Functional Cytology of the Hepatopancreas of Palaemonetes argentinus (Crustacea, Decapoda, Caridea) Under Osmotic Stress

The present work describes the effect of different salinities on the functional morphology of the P. argentinus hepatopancreas and analyses the tissue recovery after re-acclimation to freshwater. Adult prawns of both sexes at sexual rest were collected from a tributary of the Mar Chiquita coastal lagoon. The prawns were acclimated in aquaria to four salinity conditions: 0 (control), 8, 16 and 24‰. To evaluate the possible tissular recovery, after 60 days individuals from all the treatments were gradually acclimated to freshwater and maintained for other 30 days. Hepatopancreas samples were processed at the beginning of the trial and every 30 days using standard histological techniques for OM and TEM. The individuals from all the treatments, except the controls, showed a continuous weight decrease, and survival was lower when higher the salinity. At 30 days from the beginning of the experiment, hepatopancreas from 16 and 24‰ salinities showed an enlarged tubular lumen and an infolded basal lamina. Ultratructurally, nuclear retraction, cytoplasmolysis, and RER membranes separated with electron-dense content were observed in all the treatments except 0‰. After 60 days, profound alterations were observed with the three treatments. After the re-acclimation period, there was no reestablishment of the functional cytology. The tolerance to short-term salinity changes explains the capability of this prawn to inhabit in estuarine environments

Crecimiento de crías de Oreochromis niloticus alimentadas con una inclusión dietética de quistes decapsulados de Artemia

Se comparó el efecto de la inclusión dietética del 10% de quistes decapsulados de Artemia (qda) y una dieta comercial (dc), en el crecimiento y supervivencia de crías de O. niloticus, por 30 días. El peso promedio de los peces al inicio del experimento fue: 0.0173 ± 0.005 g. Las crías alimentadas con la dieta 90% dc + 10% qda fueron 0.6 g más pesadas, comparadas con dc; registrando un peso final de 1.3 ± 0.15 g. Se observaron diferencias significativas (P < 0.05) en la ganancia diaria de peso, el crecimiento específico y la conversión alimenticia entre las dietas

Revisión de los Factores de impacto en el precio de venta de la vivienda de nivel social.

This work made a revision of the impact of the incidence factors in the definition of the sale price of a construction, since a problem in any construction process is precisely the high price and therefore the possibility of realization. Assuming that the direct costs, mainly the labor force, preponderant in the definition of the cost of a building, the information was searched that allows to relate the performance of this concept, with the definition of construction times, to establish a strategy That allows the selling price to be reduced, so it is necessary to have perfectly quantified the performance that will have the labor. The study should observe the legal restrictions and health consequences of workers, the implementation of a strategy that has an impact on the times of a building process.En este trabajo, se presenta una revisión del impacto de los factores de incidencia en la definición del precio de venta de una construcción, un factor dominante en cualquier proceso constructivo es precisamente lo elevado de su precio y por lo tanto su posibilidad de realización.Partiendo del supuesto de que los costos directos, principalmente la mano de obra, predomina en la definición del costo de una edificación; se buscó la información que permita relacionar el rendimiento de este concepto, con la definición de tiempos de obra, para establecer una estrategia que permita ver disminuido el precio de venta, por lo que es necesario tener perfectamente cuantificado el rendimiento que tendrá la mano de obra. El estudio considera las restricciones legales y las posibles afectaciones en la salud de los trabajadores al tratar de implementar alguna estrategia que impacte sobre el incremento de los tiempos de un proceso de edificación

Stocking Density for Nursery Production of Redclaw Crayfish, Cherax quadricarinatus, in a Recirculating System

Redclaw crayfish, Cherax quadricarinatus, early juveniles were reared at different stocking densities in a closed recirculation system using 12-L plastic containers as rearing tanks. Initial stocking densities were 1.0, 1.5, 2.0, 2.5, and 3.0 per liter (66, 89, 111, 133, and 156 crayfish/m2, respectively). Rearing period was 42 days. Each density was tested with five replicates. Shelter (0.112 m2) was added to double the surface area of rearing tanks. Animals were fed ad libitum twice a day with a commercial diet containing 35% crude protein. There were no significant differences (P < 0.05) in length and specific growth rate (SGR) among stocking densities. Final weight and daily weight gain, however, were significantly higher at the density of 66 per m2 (1.0 per liter). Total biomass at harvest increased with density. Survival was affected by stocking density from day 28 onward, decreasing with density from 62.7 ± 7.6% obtained at 66 crayfish/m2 to 44.85 ± 8.18% at 156 crayfish/m2

Growth of fresh-water prawn Macrobrachium tenellum (Smith, 1871) juveniles fed isoproteic diets substituting fish meal by soya bean meal

Growth parameters (standard length, weight, specific growth rate and daily weight gain) of prawn Macrobrachium tenellum juveniles fed 40% crude protein isoproteic diets substituting fish meal with soya bean meal at various levels (20, 40, 60, 80 and 100%) were evaluated for 45 days under laboratory conditions. Experimental diets were compared with a 100% fish meal based diet. Total survival was recorded for all the treatments at the end of the experiment. There were no significant differences (p > 0.05) for all the growth parameters among the dietary treatments. The initial mean weight (0.36 &plusmn; 0.10 g) increased almost three times (1.00 &plusmn; 0.13 g) after 45 days. The final specific growth fluctuated from 1.82% BW/d for the 60% soya bean meal inclusion diet, to 2.62% for the 100% fish meal diet. The mean final survival was 91.66%. Growth performance of M. tenellum juveniles was not affected by the dietary soya bean meal levels tested.<br>Os parâmetros do crescimento (comprimento padrão, peso, taxa de crescimento específica e ganho diário do peso) de juveniles do Macrobrachium tenellum alimentaram a 40% a proteína crua as dietas isoproteic que substituem a refeição de peixes com feijão de soya a refeição nos vários níveis (20, 40, 60, 80 e 100%) foi avaliada por 45 dias sob condições do laboratório. As dietas experimentais foram comparadas com uma dieta baseada da refeição de peixes de 100%. A sobrevivência total foi gravada para todos os tratamentos no fim da experiência. Não havia nenhuma diferença significativa (p > 0.05) para todos os parâmetros do crescimento entre os tratamentos dietéticos. O peso médio inicial (0.36 &plusmn; 0.10 g) aumentado quase três vezes (1.00 &plusmn; 0.13 g) após 45 dias da cultura. O crescimento específico final flutuou de 1.82% BW/d para a dieta do inclusion da refeição do feijão de soya de 60%, a 2.62% obtidos para a dieta da refeição de peixes de 100%. A sobrevivência final média foi de 91.66%. O desempenho do crescimento de juveniles do M. tenellum não foi afetado pelos níveis dietéticos da refeição do feijão de soya testados