Responses of juvenile rainbow trout, under food limitation, to chronic low pH and elevated summer temperatures, alone and in combination

J. J. Dockray, I. J. Morgan, S. D. Reid, C. M. Wood

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Rainbow trout were exposed (90 days) in synthetic soft water to sublethal low pH (5.2) and a simulated climate warming scenario (+2°C above the control summer temperature range of 16.5-21°C), alone and in combination, under conditions of limited food (~4% dry body weight day-1). Weight specific oxygen consumption rates (M(O2)) were ~55% of M(O2(max)), in contrast to ~75% of M(O2(max)) found in trout fed an unlimited ration. This is likely due to a reduction in food quantity and thus feeding activity. However, the trout exposed to low pH at control temperatures exhibited higher conversion efficiencies and increased growth. in contrast, trout exposed to +2°C had reduced growth rates. No ionoregulatory disturbance occurred in any treatment, suggesting that this ration was sufficient to provide a replacement salt load in the diet. Energy budgets indicated that the limited ration resulted in a lowered optimum temperature for growth, with a greater proportion of the energy intake dissipated for metabolic expenditure, resulting in reduced conversion efficiencies. A fourfold reduction in faecal and unaccounted energy losses indicated higher absorption efficiencies than in satiation-fed trout.

Original languageEnglish
Pages (from-to)62-82
Number of pages21
JournalJournal of Fish Biology
Volume52
Issue number1
DOIs
StatePublished - Jan 1 1998

Fingerprint

food limitation
trout
rainbow
Oncorhynchus mykiss
absorption efficiency
food
summer
twenty first century
energy budget
oxygen consumption
energy
expenditure
temperature
warming
replacement
diet
disturbance
feed rations
climate
satiety

Keywords

  • Acidification
  • Energy budget
  • Food limitation
  • Rainbow trout
  • Temperature

ASJC Scopus subject areas

  • Aquatic Science

Cite this

Responses of juvenile rainbow trout, under food limitation, to chronic low pH and elevated summer temperatures, alone and in combination. / Dockray, J. J.; Morgan, I. J.; Reid, S. D.; Wood, C. M.

In: Journal of Fish Biology, Vol. 52, No. 1, 01.01.1998, p. 62-82.

Research output: Contribution to journalArticle

@article{39783fb9afc54aae9686370fc7a367b8,
title = "Responses of juvenile rainbow trout, under food limitation, to chronic low pH and elevated summer temperatures, alone and in combination",
abstract = "Rainbow trout were exposed (90 days) in synthetic soft water to sublethal low pH (5.2) and a simulated climate warming scenario (+2°C above the control summer temperature range of 16.5-21°C), alone and in combination, under conditions of limited food (~4{\%} dry body weight day-1). Weight specific oxygen consumption rates (M(O2)) were ~55{\%} of M(O2(max)), in contrast to ~75{\%} of M(O2(max)) found in trout fed an unlimited ration. This is likely due to a reduction in food quantity and thus feeding activity. However, the trout exposed to low pH at control temperatures exhibited higher conversion efficiencies and increased growth. in contrast, trout exposed to +2°C had reduced growth rates. No ionoregulatory disturbance occurred in any treatment, suggesting that this ration was sufficient to provide a replacement salt load in the diet. Energy budgets indicated that the limited ration resulted in a lowered optimum temperature for growth, with a greater proportion of the energy intake dissipated for metabolic expenditure, resulting in reduced conversion efficiencies. A fourfold reduction in faecal and unaccounted energy losses indicated higher absorption efficiencies than in satiation-fed trout.",
keywords = "Acidification, Energy budget, Food limitation, Rainbow trout, Temperature",
author = "Dockray, {J. J.} and Morgan, {I. J.} and Reid, {S. D.} and Wood, {C. M.}",
year = "1998",
month = "1",
day = "1",
doi = "10.1006/jfbi.1997.0562",
language = "English",
volume = "52",
pages = "62--82",
journal = "Journal of Fish Biology",
issn = "0022-1112",
publisher = "Wiley-Blackwell",
number = "1",

}

TY - JOUR

T1 - Responses of juvenile rainbow trout, under food limitation, to chronic low pH and elevated summer temperatures, alone and in combination

AU - Dockray, J. J.

AU - Morgan, I. J.

AU - Reid, S. D.

AU - Wood, C. M.

PY - 1998/1/1

Y1 - 1998/1/1

N2 - Rainbow trout were exposed (90 days) in synthetic soft water to sublethal low pH (5.2) and a simulated climate warming scenario (+2°C above the control summer temperature range of 16.5-21°C), alone and in combination, under conditions of limited food (~4% dry body weight day-1). Weight specific oxygen consumption rates (M(O2)) were ~55% of M(O2(max)), in contrast to ~75% of M(O2(max)) found in trout fed an unlimited ration. This is likely due to a reduction in food quantity and thus feeding activity. However, the trout exposed to low pH at control temperatures exhibited higher conversion efficiencies and increased growth. in contrast, trout exposed to +2°C had reduced growth rates. No ionoregulatory disturbance occurred in any treatment, suggesting that this ration was sufficient to provide a replacement salt load in the diet. Energy budgets indicated that the limited ration resulted in a lowered optimum temperature for growth, with a greater proportion of the energy intake dissipated for metabolic expenditure, resulting in reduced conversion efficiencies. A fourfold reduction in faecal and unaccounted energy losses indicated higher absorption efficiencies than in satiation-fed trout.

AB - Rainbow trout were exposed (90 days) in synthetic soft water to sublethal low pH (5.2) and a simulated climate warming scenario (+2°C above the control summer temperature range of 16.5-21°C), alone and in combination, under conditions of limited food (~4% dry body weight day-1). Weight specific oxygen consumption rates (M(O2)) were ~55% of M(O2(max)), in contrast to ~75% of M(O2(max)) found in trout fed an unlimited ration. This is likely due to a reduction in food quantity and thus feeding activity. However, the trout exposed to low pH at control temperatures exhibited higher conversion efficiencies and increased growth. in contrast, trout exposed to +2°C had reduced growth rates. No ionoregulatory disturbance occurred in any treatment, suggesting that this ration was sufficient to provide a replacement salt load in the diet. Energy budgets indicated that the limited ration resulted in a lowered optimum temperature for growth, with a greater proportion of the energy intake dissipated for metabolic expenditure, resulting in reduced conversion efficiencies. A fourfold reduction in faecal and unaccounted energy losses indicated higher absorption efficiencies than in satiation-fed trout.

KW - Acidification

KW - Energy budget

KW - Food limitation

KW - Rainbow trout

KW - Temperature

UR - http://www.scopus.com/inward/record.url?scp=0031888440&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031888440&partnerID=8YFLogxK

U2 - 10.1006/jfbi.1997.0562

DO - 10.1006/jfbi.1997.0562

M3 - Article

VL - 52

SP - 62

EP - 82

JO - Journal of Fish Biology

JF - Journal of Fish Biology

SN - 0022-1112

IS - 1

ER -