Impacts of acute hypoxia on the short-snouted seahorse metabolism and behaviour

Seahorses are one of the most unique and enigmatic animals, recognized as flagship species for several conservation issues. Unfortunately, seahorses' populations have been declining and their unique lifestyle may constrain the ability of these animals to evolve in the future climate scenarios. They inhabit shallow coastal waters that display daily or seasonal environmental fluctuations. Yet, few studies have scrutinized the impacts of climate changes on these iconic species. Within this context, the objective of this work was to test the effects of an extreme hypoxia exposure (~27 % dissolved oxygen for approximately 7 h) on the metabolism, behaviour and food intake of the temperate seahorse Hippocampus hippocampus. Regarding metabolism, hypoxia exposure led to a significant reduction in metabolic rates and an increase in ventilation rates. Seahorses showed signs of movement lethargy under oxygen depletion. The results show that a small but extreme exposure to hypoxia is tolerable by seahorses despite inducing metabolic and behavioural changes, that may jeopardize the future development and survival of these iconic organisms.

Descrição

The authors would also like to express their gratitude to Oceanário de Lisboa and Aquário Vasco da Gama, and to Filipa Faleiro, António Gomes and José Pereira for the availability to support this work. project grant to M.S.P. (PTCD/BIA-BMA/28647/2017, LISBOA-01-0145-FEDER-028647)- Publisher Copyright: © 2023

Palavras-chave

Behaviour Hippocampus hippocampus Hypoxia Metabolism Seahorse Environmental Engineering Environmental Chemistry Waste Management and Disposal Pollution SDG 14 - Life Below Water SDG 15 - Life on Land SDG 13 - Climate Action