Brain cooling marginally increases maximum thermal tolerance in Atlantic cod

2019 ◽  
Author(s):  
Fredrik Jutfelt ◽  
Dominique G. Roche ◽  
Timothy D Clark ◽  
Tommy Norin ◽  
Sandra A. Binning ◽  
...  
Keyword(s):  
Thermal Effects ◽  
Thermal Tolerance ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Brain Temperature ◽  
Brain Cooling ◽  
Local Cooling ◽  
Thermal Limits ◽  
The Difference ◽  
The Brain

ABSTRACTThe physiological mechanisms determining thermal limits in fishes are debated but remain elusive. It has been hypothesised that loss of motor function observed as a loss of equilibrium during an acute thermal challenge is due to direct thermal effects on brain neuronal function. To test this hypothesis, we mounted cooling plates on the head of Atlantic cod(Gadus morhua)and quantified whether local cooling of the brain increased whole-organism critical thermal maxima (CTmax). Brain cooling reduced brain temperature by 2–6°C and increased CTmaxby 0.5–0.7°C relative to instrumented and uninstrumented controls, suggesting that direct thermal effects on brain neurons might contribute to setting upper thermal limits in fish. However, the improvement in CTmaxwith brain cooling was small relative to the difference in brain temperature, demonstrating that other mechanisms (e.g., failure of spinal and peripheral neurons, or muscle) may also contribute to controlling acute thermal tolerance in fishes.Summary statementWe tested whether brain temperature sets the upper thermal limit in a fish. Selectively cooling the brain during whole-organism thermal ramping marginally increased thermal tolerance.

Accuracy and precision in stock separation of north-east Arctic and Norwegian coastal cod by otoliths - comparing readings, image analyses and a genetic method

2005 ◽  
Vol 56 (5) ◽  
pp. 753 ◽  
Author(s):  
Erik Berg ◽  
Tuula H. Sarvas ◽  
Alf Harbitz ◽  
Svein Erik Fevolden ◽  
Arnt Børre Salberg
Keyword(s):  
Visual Inspection ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Complete Separation ◽  
Arctic Cod ◽  
Genetic Method ◽  
North East ◽  
Accuracy And Precision ◽  
Growth Zones ◽  
The Difference

The distinction between north-east Arctic cod and Norwegian coastal cod, two major groups of Atlantic cod (Gadus morhua L.), has for many years been based on different distance and shape similarities between the two first translucent growth zones in the otoliths, subjectively decided by visual inspection in a binocular. To analyse the certainty of this technique, four independent readers have classified 263 cod otoliths in total from five different geographical areas. For three of the readers, between 82% and 89% of the classification results coincided with independent results based on genetic analyses. Further, 38 cod otoliths, where the readers were certain of the classification (21 north-east Arctic cod and 17 coastal cod) were classified by several image analysis methods. A complete separation was obtained by using the ratio of the circumferences of the two zones, providing a typical ratio of approximately 2 for coastal and 1.5 for north-east Arctic cod. The otolith method for separating the two types of cod has been considered adequately accurate in assessing the two stocks of cod. However, the method is sensitive to subjective interpretation, and action needs to be taken to minimise the difference in interpretation among otolith readers.

Responses in the brain proteome of Atlantic cod (Gadus morhua) exposed to methylmercury

2010 ◽  
Vol 100 (1) ◽  
pp. 51-65 ◽  
Author(s):  
Karin Berg ◽  
Pål Puntervoll ◽  
Stig Valdersnes ◽  
Anders Goksøyr
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Brain Proteome ◽  
The Brain

scholarly journals Differences in spawning time of captive Atlantic cod from four regions of Norway, kept under identical conditions

2006 ◽  
Vol 63 (2) ◽  
pp. 216-223 ◽  
Author(s):  
Håkon Otterå ◽  
Ann-Lisbeth Agnalt ◽  
Knut E. Jørstad
Keyword(s):  
Life History ◽  
Genetic Control ◽  
Environmental Conditions ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Spawning Period ◽  
Life History Parameters ◽  
Wide Range ◽  
Spawning Time ◽  
The Difference

Abstract Several hundred Atlantic cod (Gadus morhua L.) were collected from selected spawning grounds along the Norwegian coast in March 2002. Four areas or regions that represent a wide range of environmental conditions were chosen for our breeding experiments: Porsangerfjord, Tysfjord, Helgeland, and Øygarden. Cod were transported to Øygarden near Bergen, individually tagged, and kept in sea cages. In both 2003 and 2004, a total of 40 family groups (adult pairs) representing the four regions were monitored for their spawning performance in separate tanks. During the spawning period, the quantity and diameter of eggs were recorded. During 2003, the time of peak spawning differed among groups. It was evident that the broodstock from the Øygarden region spawned about one month earlier than the broodstock collected from the Helgeland region. This also occurred in 2004, two years after the cod were collected, suggesting that the difference has a genetic component. Differences in life history parameters between cod populations, such as spawning cycles as described here, could be adaptive and under genetic control. This must be taken into consideration when assessing precautionary means of overcoming the problem with escapees from future cod mariculture.

Bradycardia during face cooling in man may be produced by selective brain cooling

1979 ◽  
Vol 46 (5) ◽  
pp. 905-907 ◽  
Author(s):  
M. Caputa ◽  
M. Cabanac
Keyword(s):  
Venous Return ◽  
Human Subjects ◽  
Cardiac Response ◽  
Brain Cooling ◽  
Selective Brain Cooling ◽  
The Face ◽  
The Difference ◽  
The Brain ◽  
Face Cooling

In human subjects, bradycardia was produced by immersing the subjects' faces in water at 15 degrees C when they were hyperthermic. When they were hypothermic, the same face cooling produced tachycardia. It is suggested that the difference in cardiac response originates in selective brain cooling during hyperthermia, by venous return from the face to the brain, via ophthalmic veins.

scholarly journals Intrastock differences in maturation schedules of Atlantic cod, Gadus morhua

2011 ◽  
Vol 68 (9) ◽  
pp. 1918-1927 ◽  
Author(s):  
Peter J. Wright ◽  
Colin P. Millar ◽  
Fiona M. Gibb
Keyword(s):  
North Sea ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Reaction Norm ◽  
The North ◽  
Spatial Differences ◽  
Additive Contribution ◽  
Population Structuring ◽  
The Difference ◽  
Rate Of Decline

Abstract Wright, P. J., Millar, C. P., and Gibb, F. M. 2011. Intrastock differences in maturation schedules of Atlantic cod, Gadus morhua. – ICES Journal of Marine Science, 68: 1918–1927. Differences in maturation schedules from three subpopulations of North Sea cod (Gadus morhua) were examined using the demographic probabilistic maturation reaction norm (PMRN) approach. Declines in maturation probability with size and age were evident within the North Sea cod stock, but the magnitude of decline differed among subpopulations. The difference in the rate of decline led to significant spatial differences in recent times. Changes in maturation probability could not be explained by colonization from adjacent regions indicating a local response to conditions. The greatest decline in maturation probability followed the near collapse of regional spawning biomass during the 1980s and 1990s. A new methodology was developed to integrate the effects of temperature and competitive biomass into the estimation of the PMRN. Temperature had a positive effect on maturation probability, but could only partially explain the decreasing trend in PMRN midpoints. Consequently, regional selection for early maturing genotypes provides the most parsimonious explanation for the declines in maturation probability observed. The difference in maturation probability among North Sea cod subpopulations, and the additive contribution of temperature to the estimation of change, underscores the need to account for population structuring and to incorporate temperature as a covariate in future applications of the PMRN.

scholarly journals The acoustic dead zone: theoretical vs. empirical estimates, and its effect on density measurements of semi-demersal fish

2009 ◽  
Vol 66 (6) ◽  
pp. 1364-1369 ◽  
Author(s):  
L. G. S. Mello ◽  
G. A. Rose
Keyword(s):  
Newfoundland And Labrador ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Dead Zone ◽  
Demersal Fish ◽  
Depth Gradient ◽  
Density Measurements ◽  
Acoustic Data ◽  
Empirical Estimates ◽  
The Difference

Abstract Mello, L. G. S., and Rose, G. A. 2009. The acoustic dead zone: theoretical vs. empirical estimates, and its effect on density measurements of semi-demersal fish. – ICES Journal of Marine Science, 66: 1364–1369. The height of the acoustic dead zone, the region near the seabed where fish cannot be resolved acoustically, was calculated both theoretically (DZt) and empirically (DZe). The DZe was based on measurements of depth and trawl geometry from sensors (SCANMAR) mounted on a bottom trawl deployed during a survey off Newfoundland and Labrador in winter 2007. Acoustic data were acquired while trawling, using a 38-kHz echosounder (Simrad EK500) with a hull-mounted transducer. The DZe was calculated as the difference between the trawl-footrope depth and the corresponding acoustically sensed, seabed depth. EK500 and SCANMAR estimates of seabed depth were significantly different. The fish caught were mostly Atlantic cod (Gadus morhua). The estimates of DZe ranged between 2.0 and 3.5 m and were greater than DZt by 0.1–0.9 m in more than half the cases. Three values of acoustically derived cod densities were estimated for each tow, without dead-zone correction and with corrections for DZt and DZe. When compared with DZt corrections, DZe resulted in negative (6–12%) and positive (9–35%) corrections to cod density. A general linear model revealed that the seabed depth gradient, standard deviation of estimated fish density in the dead zone, and wind direction and force explained 85% of the difference between DZt and DZe estimates. These factors affected the detection of the seabed and biased acoustically derived indices of demersal-fish abundance.

scholarly journals Climate change in fish: effects of respiratory constraints on optimal life history and behaviour

2015 ◽  
Vol 11 (2) ◽  
pp. 20141032 ◽  
Author(s):  
Rebecca E. Holt ◽  
Christian Jørgensen
Keyword(s):  
Metabolic Rate ◽  
Life Histories ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Standard Metabolic Rate ◽  
Aerobic Scope ◽  
Trade Offs ◽  
Different Temperatures ◽  
The Difference ◽  
Common Trade

The difference between maximum metabolic rate and standard metabolic rate is referred to as aerobic scope, and because it constrains performance it is suggested to constitute a key limiting process prescribing how fish may cope with or adapt to climate warming. We use an evolutionary bioenergetics model for Atlantic cod ( Gadus morhua ) to predict optimal life histories and behaviours at different temperatures. The model assumes common trade-offs and predicts that optimal temperatures for growth and fitness lie below that for aerobic scope; aerobic scope is thus a poor predictor of fitness at high temperatures. Initially, warming expands aerobic scope, allowing for faster growth and increased reproduction. Beyond the optimal temperature for fitness, increased metabolic requirements intensify foraging and reduce survival; oxygen budgeting conflicts thus constrain successful completion of the life cycle. The model illustrates how physiological adaptations are part of a suite of traits that have coevolved.

scholarly journals Non-invasive Monitoring of Brain Temperature during Rapid Selective Brain Cooling by Zero-Heat-Flux Thermometry

2019 ◽  
Vol 3 (1) ◽  
pp. 1 ◽  
Author(s):  
Mohammad Fazel Bakhsheshi ◽  
Marjorie Ho ◽  
Lynn Keenliside ◽  
Ting-Yim Lee
Keyword(s):  
Heat Flux ◽  
Body Temperature ◽  
Rectal Temperature ◽  
Brain Temperature ◽  
Whole Body ◽  
Brain Cooling ◽  
Selective Brain Cooling ◽  
Non Invasive ◽  
Temperature Probe ◽  
The Brain

Introduction: Selective brain cooling can minimize systemic complications associated with whole body cooling but maximize neuroprotection. Recently, we developed a non-invasive, portable and inexpensive system for selectively cooling the brain rapidly and demonstrated its safety and efficacy in porcine models. However, the widespread application of this technique in the clinical setting requires a reliable, non-invasive and accurate method for measuring local brain temperature so that cooling and rewarming rates can be controlled during targeted temperature management. In this study, we evaluate the ability of a zero-heat-flux SpotOn sensor, mounted on three different locations, to measure brain temperature during selective brain cooling in a pig model. Computed Tomography (CT) was used to determine the position of the SpotOn patches relative to the brain at different placement locations.Methods and Results: Experiments were conducted on two juvenile pigs. Body temperature was measured using a rectal temperature probe while brain temperature with an intraparenchymal thermocouple probe. A SpotOn patch was taped to the pig’s head at three different locations: 1-2 cm posterior (Location #1, n=1), central forehead (Location #2, n=1); and 1-2 cm anterior and lateral to the bregma i.e., above the eye on the forehead (Location #3, n=1). This cooling system was able to rapidly cool the brain temperature to 33.7 ± 0.2°C within 15 minutes, and maintain the brain temperature within 33-34°C for 4-6 hours before slowly rewarming to 34.8 ± 1.1°C from 33.7 ± 0.2°C, while maintaining the core body temperature (as per rectal temperature probe) above 36°C. We measured a mean bias of -1.1°C, -0.2°C and 0.7°C during rapid cooling in induction phase, maintenance and rewarming phase, respectively. Amongst the three locations, location #2 had the highest correlation (R2 = 0.8) between the SpotOn sensor and the thermocouple probe.Conclusions: This SBC method is able to tightly control the rewarming rate within 0.52 ± 0.20°C/h. The SpotOn sensor placed on the center of the forehead provides a good measurement of brain temperature in comparison to the invasive needle probe.

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