Effects of temperature on feed intake and plasma chemistry after exhaustive exercise in triploid brown trout (Salmo trutta L)

Abstract

The physiological effect of temperature on feed intake and haematological parameters after exhaustive swimming in diploid and triploid brown trout (Salmo trutta) was investigated. Trout were exposed to an incremental temperature challenge (2 °C/day) from ambient (6 °C) to either 10 or 19 °C. Feed intake profiles did not differ between ploidy at 10 °C; however, triploids had a significantly higher total feed intake at 19 °C. After 24 days, each temperature–ploidy group was exposed to exhaustive swimming for 10 min. The haematological response differed between ploidy, with the magnitude of the response affected by temperature and ploidy. Post-exercise, acid–base and ionic differences were observed. Plasma lactate increased significantly from rest for both temperature and ploidy groups, but glucose increased significantly at higher temperature. Post-exercise, triploids at 19 °C had significantly higher osmolality and cholesterol than diploids, but differences were resumed within 4 h. Elevated alkaline phosphatase (ALP) and aspartate aminotransferase (AST) in fish at higher temperature suggested greater tissue damage; however, both ploidy responded similarly. Despite no significant differences in deformity prevalence, the type and location of deformities observed differed between ploidy (decreased intervertebral space with higher prevalence in tail area and fin regions for diploids, while vertebral compression, fusion in cranial and caudal trunks for triploids). These results suggest triploids have greater appetite than diploids at elevated temperature and that triploids suffer similar blood disturbances after exercise as diploids. These findings have implications for the management of freshwater ecosystems and suggest that stocking triploid brown trout may offer an alternative to diploid brown trout.

Comparative ploidy response to experimental hydrogen peroxide exposure in Atlantic salmon (Salmo salar)

“…Furthermore, it is recognised that lactate production acts as a pathway for glyconeogenesis, a metabolic pathway producing glucose, therefore, the later peak in glucose may also be related to this mechanism [ 25 , 59 , 72 ]. Additionally, lactate was not significantly affected by ploidy in this study and this supports studies assessing the stress response of diploid and triploid Atlantic salmon following confinement [ 65 , 66 ] and the effects of exhaustive exercise in diploid and triploid rainbow trout [ 44 ]. Overall, the findings for these three stress biomarkers (cortisol, glucose and lactate) supports the ability of triploids to cope similarly to diploids in response to stress induced by H 2 O 2 exposure.…”

“…While recent research has continued to elucidate the response of triploid Atlantic salmon to disease [ [39] , [40] , [41] , [42] , [43] ], their response to disease treatments is still a relatively unexplored subject, particularly relating to chemical treatments such as H 2 O 2 . This is an important milestone given the increased environmental sensitivity reported in triploids when exposed to elevated temperatures and reduced oxygen levels [ 44 , 45 ]. Considering the potential to apply triploid salmon in full commercial production, it is crucial to understand their physiological response when exposed to aquaculture medicines in order to optimise health management strategies without compromising fish welfare.…”

Differences in metabolism of triploid and diploidSalmo trutta f. lacustrisunder acclimation conditions and after exposure to stress situations

“…Several studies have been conducted to determine the effect of different stress factors on performance of triploid fish in comparison with diploid ones (e.g. temperature: Salmo salar —Bowden, Andrewartha, Elliott, Frappell, & Clark, ; temperature and oxygen concentration: S. salar —Hansen et al, ; exhaustive exercise: S. salar —Cotterell & Wardle, ; Salvelinus fontinalis —Hyndman, Kieffer, & Benfey, , , Salmo trutta —Preston, Taylor, Fjelldal, Hansen, & Migaud, ; hypoxia: Oncorhynchus mykiss —Yamamoto & Iida, ; acute handling and confinement stress: S. fontinalis and O. mykiss —Benfey & Biron, ). Also metabolism has been investigated in several studies.…”

“…Additionally, muscle glucose and blood haemoglobin concentrations were decreased at elevated temperatures (Sambraus et al, ). In brown trout ( S. trutta ) metabolism was similar in response to exhaustive exercise between triploids and diploids at 10 and 19°C suggesting that triploids tolerated stress in a similar way as diploids (Preston et al, ). In rainbow trout ( O. mykiss ) triploidization caused different expression of muscle enzymes (Babaheydari, Keyvanshokooh, Dorafshan, & Johari, ) and of antioxidative enzymes (Taghipoor, Keyvanshokooh, Salati, Pasha‐Zanoosi, & Babaheydari, ) in comparison with diploids.…”

Added value from an added chromosome: Potential of producing large fillet fish from autumn to spring with triploid rainbow trout, Oncorhynchus mykiss

“…Slower growth rate and higher FCR in triploids, relative to diploids, were recently found in one‐year‐old female rainbow trout, but in this case the difference was presumed to result from suboptimal (elevated) rearing temperatures (Karayucel, Akyüz, & Dernekbaşi, ). At higher temperatures, the decrease of growth in triploid salmonids, in relation to their diploid counterparts, may be a consequence of impaired food conversion (Hansen et al, ; Preston, Taylor, Fjelldal, Hansen, & Migaud, ). In this study, the rearing temperatures were somewhat above the optimum especially during August (>17°C), which might partially explain the slower and less efficient growth in triploids.…”