Análisis de la toxicidad del amonio en postlarvas de camarón (litopenaeus vannamei) en alta y baja salinidad.

Abstract

Ammonium is a highly toxic compound that can be present in minimal quantities; however, when its control is not taken into consideration, it can increase, causing high mortality in shrimp farming. The present work exposes the ammonium concentrations that can be toxic in post larvae of Litopenaeus vannamei. The study was using a completely randomized design where 92 experimental units were used, corresponding to 13 control units and 79 replicates and 6 treatments with doses of ammonium chloride, water and salinities between 30 ppt, 5 ppt and 1 ppt. and pH in intervals of 8.25 ± and 8.5. In the first trial, six doses of ammonium chloride were administered at salinities of 5 and 30 ppt with a pH of 8.25 and 8.5, observing the behavior of the postlarvae every four hours over a period of five days. While in the second trial, a single dose of ammonium chloride was applied in salinities of 1 ppt, pH between 8.25 and 8.5, observing the behavior of the post larvae every four hours and over a period of five days. It was observed that salinity influences the survival of postlarvae due to ammonium toxicity. During the first four hours there are no mortalities, which is an indicator of tolerance of the post larvae. However, this changes after six hours of exposure where mortalities already occur depending on the concentrations. At 1 ppm salinity the highest mortality (100%) was at a concentration of 60 mg/L with 12 hours of exposure. At 5 ppm salinity, the highest mortality (100%) was at a concentration of 120 to 240 mg/L with an exposure time of less than 8 hours. While at 30 ppm salinity the highest mortality (100%) was at a concentration of 240 mg/L with an exposure time of less than 8 hours. It has also been observed that a higher concentration of ammonium increases oxygen consumption in postlarvae of Litopenaeus vannamei.