Thermal tolerance, oxygen consumption and haemato-biochemical variables of Tor putitora juveniles acclimated to five temperatures

Abstract

A 30-day acclimation trial was conducted using Tor putitora to elucidate its thermal tolerance, oxygen consumption, haemato-biochemical variables and selected enzymatic activities at five acclimation temperatures (AT). Juveniles of T. putitora were randomly distributed among five treatment groups (20, 23, 26, 29 and 32 ± 0.5 °C). There was a significant curvilinear increase in critical thermal maxima (CT(max)) (y = -0.0693x² + 1.7927x + 34.628, R² = 0.996) and lethal thermal maxima (LT(max)) (y = -0.1493x² + 2.3407x + 35.092, R² = 0.991) with increasing AT. The oxygen consumption rate increased significantly with increasing AT. The Q₁₀ values were 1.16 between 20 and 23 °C, 3.09 between 23 and 26 °C, 1.31 between 26 and 29 °(C) and 1.76 between 29 and 32 °C of AT. The acclimation response ratios were ranged between 0.37 and 0.59. Catalase, superoxide dismutase and ATPase activities were increased linearly in liver, gill and kidney, while brain acetylcholine esterase activity decreased linearly with increasing AT. Blood glucose remained unchanged up to AT of 26 °C and increased significantly at AT of 29 and 32 °C. Haemoglobin content was increased linearly with increasing AT. The highest WBC count was observed at 20 °C, and no significant changes found till AT of 26 °C and significantly decreased at 32 °C. Total serum protein and globulin were significantly decreased with increasing AT. Highest values were observed at 20 °C and remained consistent till 26 °C, then decreased significantly. There was no significant change in A/G ratio through the AT 20-29 °C and increased significantly at 32 °C. The increase in CT(max), LT(max) and oxygen consumption rate with increasing AT may suggest that the thermal tolerance of T. putitora is dependent on its prior thermal exposure history, and it could adapt to higher AT by altering its haemato-biochemical variables.

Seasonal variation in thermal tolerance, oxygen consumption, antioxidative enzymes and non-specific immune indices of Indian hill trout, Barilius bendelisis (Hamilton, 1807) from central Himalaya, India

“…Additionally, oxygen consumption rate was also found strongly related to water temperature, dissolved oxygen and pH suggesting a strong effect of these seasonal parameters on oxygen consumption. Increase in oxygen consumption during warm season (summer, rainy and autumn) under present study is possibly due to upsurge in the total aerobic metabolism (metabolic activity) and energy demand with increase in water temperature reducing dissolved oxygen and pH as supported by many authors (Kutty and Mohamed, 1975;Das et al, 2004;Akhtar et al, 2013). Carlson and Parsons (1999) studied seasonal changes in oxygen consumption rate of the bonnethead shark and reported higher rate during the summer season that corroborate our study.…”

“…The flask was sealed and an opening in the lid was made for permitting the insertion of the dissolved oxygen probe ensuring that the seal is airtight. The chamber was placed inside the thermostatic aquarium at their respective temperature for an hour to prevent the temperature loss from the flask (Akhtar et al, 2013). The aquarium was covered with an opaque screen to minimize the visual disturbance of the experimental animal.…”

“…In fishes, thermal tolerance is influenced by numerous factors like species , prior thermal experience history (Beitinger et al, 2000Akhtar et al, 2013), acclimation temperature as well as acclimation duration (Diaz et al, 2007;Akhtar et al, 2014), salinity (Jian et al, 2003), photoperiod and seasonal effects (Hutchinson, 1976;Bulger andTremaine, 1985, Layne et al, 1987). Daily and seasonal fluctuations in environmental temperature also affect variation in thermal tolerance of many species of ectotherms including fishes (Rome et al, 2002).…”

Critical thermal maximum (CTmax) and hematology of shortnose sturgeons (Acipenser brevirostrum) acclimated to three temperatures

“…Most researchers report the relationship between CT max and T a to be a linear function; however, the variability in the data are better represented as a nonlinear relationship (also see Akhtar et al 2013). This likely is the case because there is a point where acclimation to warmer temperatures will not further increase the CT max .…”

Effects of Toxin Binder Biotox on Growth Performance Survival, Enzymatic Activity, Hematologichal and Biochemical Parameters of Fingerlings Rainbow Trout (Oncorhynchus mykiss) Fed Diets- Contaminated with Aflatoxin

“…The hemoglobin (Hb) concentrationwas analysed following the cyanmethemoglobin method [22]. Hematocrit (Hct) was determined by centrifuging blood in heparinized microhematocrit capillary tubes at 3,500 rpm for 10 min [23].…”