Internal morphological evaluation of the marsupial frog, Gastrotheca pseustes as a bioindicator species

The excessive use of fertilizers in agricultural land causes the contamination of aquatic ecosystems by eutrophication, allowing the uncontrolled growth of phytoplankton and other species of flora that cause disturbances in the balance of these ecosystems. Amphibians are especially vulnerable to this problem due to their physiological characteristics, which make them more prone to severe morphological changes or even death. The marsupial frog Gastrotheca pseustes, inhabiting the Ecuadorian Andes, is found in forest areas, grasslands, and agricultural areas, potentially contaminated with fertilizers. The present investigation evaluated the effects of nitrates and phosphates, the main components of fertilizers, on the internal morphology of G. pseustes tadpoles. Recently metamorphosed individuals of G. pseustes, exposed to different concentrations of nitrates and phosphates in their tadpole phase, were dissected, and the area of their internal organs: liver, gallbladder, stomach, spleen, and heart, were measured. Linear models were used to evaluate the effect of each treatment on the size of the studied organs. The statistical results show no significant differences in the sizes of the organs of the individuals exposed to different nitrate and phosphate treatments. These results indicate that in its tadpole phase, the marsupial frog G. pseustes is likely resistant to stress conditions caused by water contamination by nitrates and phosphates. This condition facilitates its wide distribution and abundance even in disturbed areas.

• Váldodahkki: Quilumbango Grijalva, Carla Fernanda (author)
• Materiálatiipa: bachelorThesis
• Giella: eng
• Almmustuhtton: 2023
• Fáttát: Nitratos; Fosfatos; Eutrofización; Nitrates; Phosphates; Eutrophication
• Liŋkkat: http://repositorio.yachaytech.edu.ec/handle/123456789/660