Mulinia lateralis is a native bivalve from the Western Atlantic Ocean, distributed from the Gulf of Saint Lawrence in Canada to Yucatan in Mexico. Based on morphological and genetic data of specimens collected in shrimp farms, in this work, we confirm the presence of M. lateralis in the Gulf of Guayaquil, Ecuador. Presence and its consequences of this invasive bivalve in the region is discussed.

Tilapia is a freshwater fish native to Africa that has many characteristics that make it an excellent fish for aquaculture, but it is also considered one of the most dangerous invasive exotic species in the world due to its adaptability and reproductive potential. This essay analyzes the dilemma between the benefits of these fish as an alternative to contribute to agrifood security and the threat it poses to Ecuador's aquatic biodiversity. The absence of official information makes it necessary to investigate the effect of the invasions by tilapia in the rivers, lagoons and estuaries colonized by this species. The level of action to prevent, eradicate or control the tilapia in Ecuador has been very limited and therefore the need to establish strategies to prevent its spread to areas not yet invaded is imposed. Although the government of Ecuador has regulations that restrict the introducti...

Tilapia is a freshwater fish native to Africa that has many characteristics that make it an excellent fish for aquaculture, but it is also considered one of the most dangerous invasive exotic species in the world due to its adaptability and reproductive potential. This essay analyzes the dilemma between the benefits of these fish as an alternative to contribute to agrifood security and the threat it poses to Ecuador's aquatic biodiversity. The absence of official information makes it necessary to investigate the effect of the invasions by tilapia in the rivers, lagoons and estuaries colonized by this species. The level of action to prevent, eradicate or control the tilapia in Ecuador has been very limited and therefore the need to establish strategies to prevent its spread to areas not yet invaded is imposed. Although the government of Ecuador has regulations that restrict the introducti...

            The results of a cytogenetic study carried out in two female Miniature Pinscher who died after birth, one affected with meningoencephalocele (MEC) and the other apparently normal, are presented. The analysis of 156 metaphases (75 of the specimen with pathology and 81 without pathology) showed a typical unimodal female complement 2n = 78 (76, XX) in 95.06% of all metaphases in the normal puppy, while the puppy with ECM showed a multimodal karyotype with three chromosomally distinct cell lines: 2n = 78 (36%); 77 (28%); 76 (10.67%). The remaining 25.33% of cells corresponded to cells with less than 76 chromosomes. Statistical analysis of the medians of the chromosome counts using the Man-Whitney U test between the normal (median = 78; median range = 51.81) and affected (median = 77; median range = 26.69) puppies revealed hig...

            The results of a cytogenetic study carried out in two female Miniature Pinscher who died after birth, one affected with meningoencephalocele (MEC) and the other apparently normal, are presented. The analysis of 156 metaphases (75 of the specimen with pathology and 81 without pathology) showed a typical unimodal female complement 2n = 78 (76, XX) in 95.06% of all metaphases in the normal puppy, while the puppy with ECM showed a multimodal karyotype with three chromosomally distinct cell lines: 2n = 78 (36%); 77 (28%); 76 (10.67%). The remaining 25.33% of cells corresponded to cells with less than 76 chromosomes. Statistical analysis of the medians of the chromosome counts using the Man-Whitney U test between the normal (median = 78; median range = 51.81) and affected (median = 77; median range = 26.69) puppies revealed hig...

The study of mercury content in marine sediments is presented in nine sampling stations of Estero Huaylá in Puerto Bolívar (Ecuador), by means of spectrophotometry of atomic absorption with flame nebulization and with the generation of hydrides with atomization in a quartz cell. The ecological risk assessment was determined by calculating the pollution factor (fi) and the potential ecological risk index (IREP) at each sampling point. The result obtained, for each metal, was compared with the values of the existing sediment quality guide: CEL (Concentration with limit effect) and CEP (Concentration with probable effect). The results show that the mercury concentration was high in all stations with a minimum of 0.89 and a maximum of 5.79 μg/g, while for the values between 0.04 and 0.09 plomo were obtained μg/g. With respect to toxicological risk, mercury and lead concentration values e...

Se presenta el estudio del contenido de mercurio en sedimentos marinos en nueve estaciones de muestreo del Estero Huaylá en Puerto Bolívar (Ecuador), mediante espectrofotometría de absorción atómica con nebulización de llama y con la generación de hidruros con atomización en celda de cuarzo. La evaluación del riesgo ecológico fue determinada calculando el factor de contaminación (fi) y el índice de riesgo ecológico potencial (IREP) en cada punto de muestreo. El resultado obtenido, para cada metal, fue comparado con los valores de la guía de calidad de sedimentos existentes: CEL (Concentración con efecto limite) y CEP (Concentración con efecto probable). Los resultados demuestran que la concentración de mercurio fue elevada en todas las estaciones con un mínimo de 0,89 y un máximo de 5,79 μg/g, mientras que para el plomo fueron obtenidos valores entre 0,04 y 0,09 μg/g...