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The respiration of young coho Oncorhynchus kisutch at gradually declining oxygen levels and during recovery from oxygen deprivation
Author(s) -
Waller U.,
Rosenthal H.,
Black E. A.
Publication year - 1997
Publication title -
journal of applied ichthyology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 62
eISSN - 1439-0426
pISSN - 0175-8659
DOI - 10.1111/j.1439-0426.1997.tb00104.x
Subject(s) - respiration , oxygen , zoology , respiration rate , biology , oncorhynchus , chemistry , fish <actinopterygii> , fishery , botany , organic chemistry
The respiration of coho salmon, Oncorhynchus kisutch , weighing between 15 and 50 g was measured at gradually declining oxygen levels and at temperatures ranging between 14 and 17°C. The maximum and minimum oxygen concentrations tested were 250 and 40 μmol L −1 , respectively. Respiration rates were measured for 1 h periods before oxygen concentration was lowered by 12.5 or 25.0 μmol oxygen L −1 . At the end of these endurance tests the oxygen level was returned to normoxic conditions and respiration rates were determined for the recovery period. Under normoxic conditions (> 200 μmol L −1 ) the respiration of coho levelled around 5.1 μmol g −1 wet weight h −1 . At intermediate levels between 150 and 200 μmol oxygen L −1 , the average rate increased to 5.8 μmol g −1 h −1 , which could be attributed to higher spontaneous activity of the test animals. At low oxygen levels (< 150 μmol −1 ) average respiration rates dropped to values between 5.5 and 5.7 μmol g −1 h −1 , reaching a minimum of 3.8 μmol g −1 h −1 at oxygen levels below 50 μmol L μ . First mortality was observed in this range. After exposure to reduced oxygen levels the fish maintained a higher respiration rate when again exposed to normoxic oxygen levels above 200 μmol L −1 . Increased respiration rates were observed for a recovery period of 6 h.