Short and long term increased temperature effects on Halobatrachus didactylus metabolic rate.

JUAN MANUEL MOLINA; ANDREAS KUNZMANN; PEDRO GUERREIRO

Santiago de compostela

Congreso; SIBIC2020, VIII Congreso ibérico de Ictiología.; 2020

Sociedad iberica de ictiologia

In the last decades the scientific community has focused the studies on aspects of climate change. Given that physiological processes are the link between the environment and the individual-level responses, studies focusing on the effects of environmental drivers on the physiology of marine organisms are sorely needed. In this aspect, the study of fish responses to the stressors related to climate change is of high relevance for sedentary species without the ability to migrate along the temperature gradient. The goal of this study is to quantify and determine the short and long term effects of increased temperature on the stress response of the toadfish Halobatrachus didactylus using respirometry. For short term assesment, 32 fish were subjected to accute temperature increases from 12 to 28 °C while in respirometry chambers to measure the changes in metabolic rates. For long term assesment 24 fish were transferred to treatment tanks with two temperatures (12 and 28 °C). Fish were hold under the different treatments for 30 days. Baseline and maximum metabolic rates were obtained, and food conversion was estimated for each treatment. For the short term, metabolic rate increased three fold from 12 to 28 °C. Fish from the long term high temperature conditions exhibited a decrease in weight (mean -3.1%) and a higher metabolism (average baseline 24.6 mgO2 h-1 kg-1, average maximum 36.4 mgO2 h-1 kg-1). Fish under low temperature gained weight (mean +9.3%) and their metabolism remained low (average 4.5 mgO2 h-1 kg-1, average maximum 10.6