Efecto del tamaño de las reproductoras en la producción de alevines de <i>Cichlasoma festae</i> en condiciones semicontroladas en Ecuador

Objetivo. Evaluar los efectos de la zona de habitad y sexo en la respuesta bioquímica sérica y morfométrica de Ichthyoelephas humeralis en ecosistemas loticos de la provincia Los Ríos, Ecuador. Materiales y métodos. Se identificó una de las especies nativas (I. humeralis) que más se comercializan en los cantones de Quevedo, Mocache y Fumisa de la provincia Los Ríos. Se capturaron 60 ejemplares por cada zona (180 total). Se realizó el sexado y se determinó el peso vivo, la longitud, el grosor de la cabeza, cuerpo y cola; factor de condición y bioquímica sanguínea (glucosa, colesterol y triglicéridos). Resultados. Para los indicadores morfométricos no hubo interacción zona-sexo. Solo existieron diferencias significativas (p<0.05) para el efecto del sexo sobre el peso vivo, longitud, grosor de la cabeza, cuerpo y cola, con los mayores valores para los machos (284.98 g; 29.32 cm; 6.77 cm; 14.81 cm y 7.80 cm, respectivamente) excepto para el Factor de condición el cual no mostró diferencias estadísticas. Para la bioquímica sanguínea los resultados más elevados para glucosa y triglicéridos en Quevedo con 162 mg/dL y 320.67 mg/dL, respectivamente mientras que para el colesterol fue de 130 mg/dL para Fumisa. Conclusiones. Se evidenció el efecto del sexo sobre los indicadores morfométricos, con los mejores resultados para los machos. Mientras que la bioquímica sanguínea mostró variabilidad con respecto a las zonas con los mayores resultados para Quevedo, producto a las fluctuaciones en condiciones naturales del ambiente y la alimentación.

Section: Materiales Y Métodosunclassified

Bioquímica sanguínea y morfometría en Ichthyoelephas humeralis de ecosistemas lóticos, provincia Los Ríos, Ecuador

et al. 2021

“…The river network of Ecuador is complex and diverse, highlighting the Guayas River Basin (CHG), with an extension of 53,299 km 2 ( Figure 1 ), as the largest basin from South America on the Pacific side of the continent [ 8 ]. It extends between the parallels 00°14′ S and 02°27′ S, and the meridians 78°36′ W and 80°36′ W. The CHG is made up of seven sub-basins with high geomorphological, climatic and biological diversity [ 9 ].…”

Section: Introductionmentioning

confidence: 99%

“…Previously, this research group has made the morphological, meat quality and productive characterization of different native freshwater species of Guayas River Basin located in the coast zone of Ecuador: Cichlasoma festae by González et al [ 31 , 32 ] and Rodriguez et al [ 4 , 8 ]; Andinoacara rivulatus by Caez et al [ 33 ] and González et al [ 34 ]; Dormitator latifrons by González-Martínez et al [ 35 ]; Hoplias microlepis by González-Martínez et al [ 36 ]. The situation of these native endemic fish water populations in Ecuador includes risk criteria to consider them as threatened species, including the reduction of population; modification, fragmentation and destruction of habitats; the increase of non-native species ( Oreochromis spp.…”

Section: Introductionmentioning

confidence: 99%

“…The situation of these native endemic fish water populations in Ecuador includes risk criteria to consider them as threatened species, including the reduction of population; modification, fragmentation and destruction of habitats; the increase of non-native species ( Oreochromis spp. ); overfishing with illegal gear; environmental contamination; loss of modification of natural hydrological regime, including basin river connectivity; and, finally, climate change [ 8 , 37 , 38 , 39 ]. In each case, factors such as sex, production system (wild and cultured) and capture area, among others, were studied.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Usefulness of Discriminant Analysis in the Morphometric Differentiation of Six Native Freshwater Species from Ecuador

Heredero²,

et al. 2021

Animals

Self Cite

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.

Morphological Variations of Wild Populations of Brycon dentex (Characidae, Teleostei) in the Guayas Hydrographic Basin (Ecuador). The Impact of Fishing Policies and Environmental Conditions

Heredero

et al. 2021

Animals

The Guayas, located in Ecuador, is the largest basin in the Pacific Ocean and has an inventory of 123 native freshwater species. Most of these are endemic species that are threatened or at-risk due to anthropogenic activity and the modification, fragmentation, and destruction of habitats. The aim of this study was to determine the morphometric variation in three wild populations of Brycon dentex in the Guayas basin rivers and their connections to fishing management and environmental conditions. A total of 200 mature fish were captured, and 26 morphometric parameters were measured. The fishing policies (Hypothesis 1) and environmental conditions (Hypothesis 2) were considered fixed factors and were validated by t-tests. The morphological variation among the three populations (Hypothesis 3) was validated through a discriminant analysis. Fishing policies and resource management were found to generate morphological differences associated with body development. In addition, the environmental conditions were found to influence the size and structure of Brycon dentex populations. The analyzed populations were discriminated by the generated morphometric models, which differentiated Cluster 1 (Quevedo and Mocache rivers) with high fishing pressure from Cluster 2 (Pintado river) with medium–low fishing pressure. Morphometric differentiation by discriminant analysis is a direct and economic methodology that can be applied as an indicator of diversity maintenance.