Ecuador, a country exhibiting large developments in fish farming, has a great variety of freshwater native fish. Among these fish is the Dormitator latifrons or chame, which has characteristics that make its farming prone to occur at a quite-developed stage. However, morphological characterization is required to establish a conservation program. In this study, 300 chames were captured in the Manabi province (Ecuador) to analyze their morphostructural model and to evaluate the effects of sex and the production system through multivariant techniques. The fish from the farm presented morphological measurements that were statistically (p < 0.05) higher than those of wild fish. Males were taller, longer, and wider than females, although the differences were not significant (p > 0.05). The percentage of correct adscription was 84%, with larger errors in wild fish. The morphostructural model had a high homogeneity, with 89.95% significant correlations (p < 0.05), and wild male and female fish were more homogeneous. The farm fish were larger because of the higher food availability. Moreover, the species exhibited sexual dimorphism, although there were no great differences in the morphometric measurements. This study shows the great biodiversity that naturally exists in Ecuadorian rivers. Therefore, it is of great interest to develop a chame breeding and conservation program.

This paper presents preliminary results from a power-quality audit conducted at a high-tech campus over the last year. Voltage and current were measured at various R&D buildings; it was found that the main problems for the equipment installed were voltage sags and surges. The paper examines the causes and effects of power disturbances that affect computer or any other microprocessor-based equipment and analyses the auto-protection capabilities of modern power supplies. The convenience of ‘enhanced power supply’ or ‘low-cost customer-side’ protection solutions is also discussed. Finally, it addresses the role of the standards on the protection of electronic equipment and the implications for the final customer.

The aim of this research was to find out the morphometric differentiation of six native freshwater species in the Guayas Hydrographic Basin (Ecuador) by means of discriminant analysis. A total of 1355 mature fishes (Cichlasoma festae, Andinoacara rivulatus, Dormitator latifrons, Bryncon dentex, Hoplias microlepis and Leporinus ecuadorensis) were captured and 27 morphometric measurements and 20 landmarks were used. Two-way analysis of variance with species and sex as fixed factors and discriminant analysis were applied. The selection of the most discriminant variables was made applying the F of Snedecor, Wilks’-Lambda and the 1-Tolerance. While sex within species had no significant effect on the morphology, differences among species were significant. Twenty-seven morphological variables showed highly significant differences among six native freshwater species. Nine biometric variables with high discriminant power were selected. The six species analyzed were discriminated by the morphometric models generated, thus showing that discriminant analysis was useful for differentiating species. The morphometric differentiation by discriminant analysis is a direct, simple and economic methodology to be applied in situ in rural communities. It favors the implementation of a livestock development program and it could be used with other native freshwater species in the Guayas Hydrographic Basin.

Ecuador is considered the fishing capital of the Southeastern tropical Pacific with more than 900 native species. Cichlasoma festae represents an economic important freshwater species of much local use. Thus, in this study, our goal was to characterize this fish species during juvenile stages, as the first step for its conservation and valuation, and also for the preparation of proposals for sustainable rural development and formulation of plans for environmentally responsible fisheries management. The study lasted 25 weeks and was undertaken in the ictiohidrographic area of Province of Los Rios, which accounts for 35 % of native fish species in Ecuador. Weekly, the individual biometric parameters total length (L), body width (BW) and body depth (BD) of 90 juveniles of C. festae were measured. Growth was determined using non-linear biological regression models. The average standard length varied between 6.30 cm and 12.25 cm and the average weight varied between 4.99 and 35.71 g. The length-weight relationship was best fit by the equation 15 lnW=-3.92+2.96 ln(L)"> , and the species presented negative allometric growth. Finally, the best fit for the growth of C. festae was the Von Bertalanffy’s model where 15L∞"> = 19.758 cm, k = 0.028 cm week^-1 and 15t0 "> = -14.463 week^-1. We concluded that to support sustainable and reliable fisheries production studies, the growth record from length may be obtained with standard methods as those evaluated in this study, or may be obtained with new safer tools such as photogrammetry.

This study evaluated the influence of rearing system (cultured vs. wild rearing systems), and fish sex on carcass and flesh traits of A. rivulatus, raised in Ecuador. Three hundred mature specimens from A. rivulatus were captured, 150 from each origin. Slaughter yield and dress-out resulted similar for both rearing system, and average fillet yield for cultured fish was significantly higher than for wild fish, while cooking loss was significantly lower. Dress-out was significantly higher in females. Significant differences were found in wet percentage, ash, fat and protein content in both rearing systems, but only wet percentage was significantly affected by sex. Palmitic, oleic and arachidonic acids had the maximum percentage of saturated (SFA) and mono/poly unsaturated (MUFA/ PUFA) fatty acids, respectively. In cultured and wild fish, differentiations were also found in PUFA/SFA, docosahexaenoic acid (DHA)/eicosapentaenoic acid (EPA), atherogenicity (IA), and thrombogenicity (IT) indices, along with P, K, Mg, Cu and Fe. Sex and rearing system significantly influenced most of the analyzed characteristics of carcass and flesh of A. rivulatus. Fillet high yield and its proximate composition categorize A. rivulatus as a suitable food. These results provide valuable nutritional information about native species for consumers in Ecuador. Highlights: The rearing system (cultured vs. wild rearing systems), and fish sex affect the carcass and flesh traits of A. rivulatus. Fillet high yield and its proximate composition categorize A. rivulatus as a suitable food. The proximate composition of fillet from cultured A. rivulatus is more adequate than those of wild A. rivulatus. The cultured A. rivulatus contains higher n-3 and n-6 PUFA percentages and adequate n-3/n-6 ratio.