340 
Fishery Bulletin 117(4) 
Table 1 
Results from trials with different treatment combinations conducted on striped bass (Morone saxatilis) at the Marine Resources 
Research Institute, South Carolina Department of Natural Resources, during June—December 2014. Partial pressure of oxygen in 
water (P0 2 ), fish wet weight, fish total length (TL), fish relative condition factor (Kn), standard metabolic rate (SMR), maximum 
metabolic rate (MMR), aerobic metabolic scope (AMS), exhaustion time, and fish sample size (n) were measured for each combi¬ 
nation of temperature and dissolved oxygen (DO) concentration. Lettered subscripts indicate significant differences between tem¬ 
perature treatments, and numbered subscripts indicate significant differences between DO-level treatments. Standard deviations 
of means are given in parentheses. 
Temp. 
(°C) 
DO level 
(mg/L) 
P0 2 
(kPa) 
Wet weight 
(g) 
TL 
(mm) 
Kn 
SMR 
(mg-kg-bh- 1 ) 
MMR 
(mg-kg _1 -h _1 ) 
AMS 
(mg-kg _1 -h _1 ) 
Exhaustion 
time (s) 
n 
20 
2.5 
5.74 a (0.01) 
404 b (67) 
340 b (17) 
1.00 a (0.04) 
?9 ab G5) 
274 a !(60) 
194 a j (47) 
8499!(957) 
5 
20 
3.0 
6.89 b (0.04) 
447 b (37) 
348 b (13) 
1.04 a (0.04) 
?3 ab (21) 
294 a2 (36) 
221 a2 (27) 
8994J(1118) 
5 
20 
4.0 
9.14 c (0.02) 
386 b (53) 
337 b (13) 
0.99 a (0.03) 
64 ab (13) 
398 a3 (42) 
334 a 3 (43) 
10,954 2 (923) 
5 
25 
2.5 
6.27 d (0.01) 
504 a (67) 
364 a (17) 
1.03 ab (0.07) 
75 b (15) 
279 aW (29) 
203 ab l (21) 
9932j(1497) 
7 
25 
3.0 
7.55 e (0.01) 
512 a (43) 
366 a (14) 
1.03 ab (0.04) 
83 b (25) 
3H a b, 2 134) 
227 ab 2 (31) 
10,135i (1460) 
7 
25 
4.0 
10.04 f (0.03) 
504 a (65) 
364 a (18) 
1.03 ab (0.08) 
66 b (9) 
429 ab 3 (80) 
363 ab 3 (77) 
12,016 2 (2148) 
7 
32 
2.5 
6.83 b (0.02) 
410 b (62) 
349 b (11) 
0.95 b (0.09) 
106 a (34) 
334 bl (28) 
227 bl (46) 
8727i(1147) 
5 
32 
3.0 
8.16 g (0.01) 
436 b (19) 
353 b (10) 
0.98 b (0.05) 
101 a (21) 
376 b2 (28) 
275 b2 (33) 
8710j(1054) 
5 
32 
4.0 
10.91 h (0.04) 
426 b (58) 
354 b (12) 
0.95 b (0.06) 
93 a (8) 
530 b3 (37) 
436 b3 (35) 
10,440 2 (610) 
5 
Fish were moved to an outside 12,000-L brackish-water 
flow-through system (salinity: ~5) on 9 April 2014 and 
held until they were brought indoors for acclimation. 
While held outside, they experienced natural lighting 
and temperature conditions similar to those of the Ashley 
River during spring and summer (ratio of hours of day¬ 
light to hours of night: ~12 h:12 h in spring and ~14 h:10 h 
in summer; temperature range: 20-30°C). 
Before each set of experiments was conducted, a sub¬ 
set of striped bass (—50 fish for each temperature treat¬ 
ment) were moved into a circular 1600-L recirculating 
tank housed in an environmental chamber. Fish were 
held in lighting conditions with a ratio of 13 h of light to 
11 h of dark and were acclimated to the desired salinity 
(1) and test temperature (20°C, 25°C, or 32°C) before test¬ 
ing. Dechlorinated tap water and Instant Ocean 6 sea salt 
(Instant Ocean, Blacksburg, VA) were used to make water 
with a salinity of 1. Fish in the group held in 20°C water 
were acclimated for a mean of 64 d (standard deviation 
[SD] 7) and range of 51-75 d, fish in the group held in 25°C 
water were acclimated for a mean of 26 d (SD 11) and a 
range of 9-47 d, and fish in the group held in 32°C water 
were acclimated for a mean of 46 d (SD 15) and a range of 
26-70 d. Therefore, acclimation times ranged from 9 d to 
several weeks. Although 9 d is a relatively short thermal 
acclimation period, it was considered adequate because 
the temperature of the outside tank from which fish were 
collected before each experiment was similar to the tem¬ 
peratures of the experimental tanks (i.e., fish were moved 
to the 20°C tank in the spring and to the 25°C and 32°C 
tanks in the summer). 
6 Mention of trade names or commercial companies is for identi¬ 
fication purposes only and does not imply endorsement by the 
National Marine Fisheries Service, NOAA. 
To account for any effect of acclimation time on metabolic 
rates or swimming performance, we included acclimation 
time as a covariate in the statistical models. During the 
acclimation period, fish were fed to satiation once daily 
with a commercially pelleted diet (5.0-mm, slow-sinking 
Finfish Silver, Zeigler Bros. Inc., Gardners, PA). 
Seven days prior to use in a trial, individual fish were 
transferred from the holding tank into a 70-L rectangu¬ 
lar aquarium equipped with an air-driven Hydro-Sponge 
1 filter (Aquarium Technology Inc., Decatur, GA) and an 
air stone to promote water mixing and oxygenation; all fish 
were held at air saturation >90% and at their test tem¬ 
perature. Water was changed in aquaria daily to prevent 
buildup of nitrogenous waste. Food was withheld during 
this 7-d period, which is an adequate amount of time to 
ensure that digestion and specific dynamic action do not 
influence oxygen consumption rates (Clark et al., 2013). 
Five fish held in 20°C water and 5 fish held in 32°C water 
were tested at each DO level; 7 fish held in 25°C water were 
tested at each DO level (Table 1). 
Oxygen consumption measurements 
Standard metabolic rate, MMR, and AMS were deter¬ 
mined by using intermittent-flow respirometry at tem¬ 
peratures of 20°C, 25°C, and 32°C and DO concentrations 
of 4.0, 3.0, and 2.5 mg/L in a full factorial design. The 
P0 2 of each treatment combination is reported in Table 1. 
Trials on temperature-acclimated fish were conducted 
during 19 June-19 December 2014. The day prior to a 
trial, a single fish was anesthetized directly in its aquar¬ 
ium with Finquel tricaine methanesulfonate (Argent 
Chemical Laboratories Inc., Redmond, WA) at a concen¬ 
tration of 0.1 g/L. Fish were removed from the aquarium 
with a dip net and then measured and weighed (Table 1) 
