We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Testing hypoxia: physiological effects of long-term exposure in two freshwater fishes.
- Authors
Gilmore, Kayla L.; Doubleday, Zoe A.; Gillanders, Bronwyn M.
- Abstract
Hypoxic or oxygen-free zones are linked to large-scale mortalities of fauna in aquatic environments. Studies investigating the hypoxia tolerance of fish are limited and focused on marine species and short-term exposure. However, there has been minimal effort to understand the implications of long-term exposure on fish and their ability to acclimate. To test the effects of long-term exposure (months) of fish to hypoxia we devised a novel method to control the level of available oxygen. Juvenile golden perch ( Macquaria ambigua ambigua), and silver perch ( Bidyanus bidyanus), two key native species found within the Murray Darling Basin, Australia, were exposed to different temperatures (20, 24 and 28 °C) combined with normoxic (6-8 mgO L or 12-14 kPa) and hypoxic (3-4 mgO L or 7-9 kPa) conditions. After 10 months, fish were placed in individual respirometry chambers to measure standard and maximum metabolic rate (SMR and MMR), absolute aerobic scope (AAS) and hypoxia tolerance. Golden perch had a much higher tolerance to hypoxia exposure than silver perch, as most silver perch died after only 1 month exposure. Golden perch acclimated to hypoxia had reduced MMR at 20 and 28 °C, but there was no change to SMR. Long-term exposure to hypoxia improved the tolerance of golden perch to hypoxia, compared to individuals held under normoxic conditions suggesting that golden perch can acclimate to levels around 3 mgO L (kPa ~ 7) and lower. The contrasting tolerance of two sympatric fish species to hypoxia highlights our lack of understanding of how hypoxia effects fish after long-term exposure.
- Subjects
HYPOXIA (Water); MACQUARIA ambigua; BIDYANUS bidyanus; ACCLIMATIZATION; FISH mortality; PHYSIOLOGY
- Publication
Oecologia, 2018, Vol 186, Issue 1, p37
- ISSN
0029-8549
- Publication type
Article
- DOI
10.1007/s00442-017-3992-3