Resumo O “blenny da patagônia” (Eleginops maclovinus) é uma espécie endêmica da América do Sul, com características fisiológicas que facilitariam sua incorporação na aquicultura chilena. No entanto, atualmente não há alimento artificial específico que possa ser usado para criar E. maclovinus. Diante desse problema, este estudo descreve a composição proximal e o perfil de ácidos graxos do caranguejo Hemigrapsus crenulatus, um dos principais alimentos de E. maclovinus. O objetivo do estudo é servir como informação básica para o desenvolvimento de uma dieta artificial específica para espécies juvenis desse peixe. A análise proximal do corpo completo de H. crenulatus indica que ele é composto, principalmente, de cinzas (35,9%), proteínas (32,2%), glicídios (19,8%) e lipídios menores (3,6%). O perfil de ácidos graxos é 40,7% PUFA, 29,7% MUFA e 29,5% SAFA, e os ácidos mais abundantes são eicosapentaenoico (18,8%), oleico (6,8%) e palmítico (16,6%), respectivamente. H. crenulatus possui o mais alto nível de proteínas, lipídios e PUFAs entre as espécies da infraordem de Brachyura.

Abstract The Patagonian blenny (Eleginops maclovinus) is species endemic to South America with physiological characteristics that would facilitate its incorporation into Chilean aquaculture. However, there is currently no specific artificial food that can be used to raise E. maclovinus. In light of this problem, this study describes the proximal composition and fatty acid profile of the crab Hemigrapsus crenulatus, one of the main foods of E. maclovinus. The purpose of the study is to serve as basic information for the development of a specific artificial diet for juveniles of this fish species. The proximal analysis of the complete body of H. crenulatus indicates that it is mainly composed of ash (35.9%), proteins (32.2%), glucides (19.8%) and minor lipids (3.6%). The fatty acid profile is 40.7% PUFAs, 29.7% MUFAs and 29.5% SAFAs, and the most abundant acids are Eicosapentaenoic (18.8%), Oleic (6.8%) and Palmitic (16.6%), respectively. H. crenulatus has highest level of proteins, lipids and PUFAs among the species of the Brachyura infraorder.

Salt baths in the production system of salmonids in fresh water, are important for the prevention and control of different diseases such as saprolegnia fungus. This standard procedure generates a rapid depletion of O2 in the water, leading to a significant increase of CO2, affecting blood parameters associated with animal welfare, such as Na+, Cl-, glucose and protracted hypercarbia. The aim of this study was to evaluate the response field of blood parameters related to fish welfare and the physical-chemical parameters of water to which they are subject during this period, comparing two sets of bath salt. One group of farmed Atlantic salmon (Salmo salar) in the pre-smolt stage was exposed in a salt bath system with the usual conditions and a second to a recirculation system with a waterfall for degasification, with two different exposure periods of one and two hours. The results of the concentration of CO2 in the water show significant variations between the two systems without recirculation compared to the control condition and salt. Significant differences were observed between the recirculating system and the control in blood levels of pCO2 and HCO3, but not pH. Our field data also show that salt baths that are performed regularly at the fish farms generate significant effects on blood parameters associated with animal welfare specifically fish pCO2 and HCO3 causing minor hypercarbia without generating blood acidosis. The addition of water recirculation with a waterfall does not affect blood parameters.

Los baños de sal, dentro del sistema productivo de salmónidos en agua dulce, son un paso clave en la prevención y el control de diferentes enfermedades como la saprolegnia. Este procedimiento habitual genera un agotamiento rápido del O2 en el agua, lo que genera un aumento significativo del CO2 en el agua, afectando parámetros sanguíneos asociados a bienestar animal, como Na+, Cl-, glucosa y en situaciones prolongadas hipercapnia. Este trabajo tiene como objetivo evaluar en terreno la respuesta de parámetros sanguíneos asociados a bienestar de los peces y parámetros físico-químicos del agua a la que están sometidos en este periodo, comparando dos sistemas de baño de sal. Para ello se sometió a un grupo de Salmo salar en etapa pre-smolt a un baño de sal habitual, otro grupo a un sistema de recirculación con cascada de agua para su desgasificación y un grupo control sin sal, exponiéndolos a diferentes periodos de una y dos horas. Los resultados de la concentración de CO2 en el agua muestran variaciones significativas entre ambos sistemas con y sin recirculación para la condición control y con sal. Los niveles sanguíneos evaluados en terreno de PCO2 y HCO3 presentaron diferencias significativas respecto del sistema con recirculación y al control, no así los niveles sanguíneos de pH. Nuestros datos de terreno demuestran que los baños de sal que se realizan con regularidad en los centros de cultivo generan efectos significativos sobre parámetros sanguíneos asociados a bienestar animal de los peces, específicamente PCO2 y HCO3, provocando hipercapnia leve sin generar acidosis sanguínea, al añadir recirculación del agua con una cascada a los baños de sal, no se ven afectados los parámetros sanguíneos.

The Cu, Cr and Pb concentrations were determined in Mugil cephalus and Eleginops maclovinus, fish species inhabiting the mouths of the Maule and Mataquito Rivers (Maule Región, Chile) which are consumed by the coastal population in large quantities. Measurements were taken by fíame atomic absorption spectroscopy to analyse representative muscle tissue of the two species. The method was validated using certified reference material (DOLT-1). The concentration ranges of Cu, Cr and Pb (mg· kg-1, dry weight) mMugil cephalus from the Maule river were: Cu 0.5-36.2; Cr 0.3-6.3; Pb 0.4-11.2 and from the Mataquito river varied between: Cu 0.6-23.2; Cr 0.3-6.0 and Pb 0.4-11.1. Forthe species Eleginops maclovinus from the Maule river the concentration ranges were: Cu 0.8-13.2; Cr 0.2-5.6; Pb 0.2-9.6 and from the Mataquito river: Cu 0.5-18.4; Cr 0.2-3.2 and Pb 0.3-4.0. The concentration ranges of Cu and Cr recorded inthe two species of fish are within the levels permitted by FAO and EP A, however the concentrations of Pb in Mugil cephalus originating from both estuaries exceeds the levels permitted by current legislation. The statistical analysis done with one way ANOVA (p < 0.05) indicated that for each metal there are no significant differences between the species and the two sampling sites; however with two way ANOVA between the species and the two sampling sites a significant difference was found for Cu and Cr, but not for Pb.

A coastal-lake wetland is a type of inland water ecosystem that does not occur very frequently in Chile, of which lakes Budi, Huillinco and Cucao are examples. Textural differences were found in the various constituent parts of the coastal lake sediments. Gravel was the smallest fraction and showed significant differences among the three coastal lakes (P < 0.05). Significant differences (P < 0.05) were also recorded for the sand and mud fractions. Lakes Cucao and Huillinco are described as muddy sand, in contrast to Lake Budi, which is described as sandy mud, composed primarily of mud with a smaller percentage of sand. There were statistical differences among the lakes with regard to the contributions of organic matter in each fraction. The macrofauna in these bodies of water belongs to the fauna inhabiting estuary environments in southern Chile. Lake Budi had seven taxa, and lakes Huillinco and Cucao ten species of macrofauna each. There were no significant differences in the number of species captured at the three coastal lakes (P > 0.05), but differences did emerge in comparisons made among the sampling stations. Total abundances showed significant differences (P < 0.05) in comparisons made both among the lakes and the stations. Salinity and grain size could be limiting the density and number of species at the lakes.

Un lago costero es un tipo de ecosistema de agua interior que no se encuentra muy frecuentemente en Chile; los lagos Budi, Huillinco y Cucao son ejemplos de este tipo de ecosistemas. Se encontraron diferencias texturales en los sedimentos de estos lagos costeros. La grava constituyó el porcentaje más pequeño, con diferencias significativas entre los tres lagos (P < 0.05). Los porcentajes de arena y de fango también presentaron diferencias significativas (P < 0.05). Los lagos Cucao y Huillinco se describen como de arena fangosa, en contraste con el Lago Budi que se describe como fango arenoso, compuesto principalmente de fango con un menor porcentaje de arena. Se encontraron diferencias estadísticas entre los lagos con respecto a las contribuciones de la materia orgánica a cada una de las fracciones. La macrofauna presente en estos cuerpos de agua pertenece a la fauna que habita en ambientes estuarinos en el sur de Chile. El Lago Budi presentó siete taxa y los lagos Huillinco y Cucao diez especies de macrofauna cada uno. No hubo ninguna diferencia significativa entre el número de especies capturadas en los tres lagos costeros (P > 0.05), pero sí surgieron diferencias al comparar entre estaciones. Las abundancias totales presentaron diferencias significativas (P < 0.05) en las comparaciones hechas entre los lagos y entre las estaciones. La salinidad y el tamaño del sedimento podrían estar limitando la densidad y el número de especies en estos lagos.