Exercise improves growth, alters physiological performance and gene expression in common carp (Cyprinus carpio)

Abstract

It has been suggested that induced swimming has the potential to improve the growth performance of fish. We tested this hypothesis by measuring growth, metabolic efficiency and physiological capacity of common carp (Cyprinus carpio). Fish were swum at different exercise regimes: 0.0 (control), 1.5 and 2.5 body lengths per second (BL/s) in 1600 L recirculating raceways for 4 weeks. The results showed a significant increase in weight gain, specific growth rate, improved feed conversion efficiency, and a higher hepatosomatic index for 2.5 BL/s exercised fish compared to control. Glycogen, protein and lipid energy stores in hepatic and muscular tissue showed limited differences among experimental groups. Likewise, plasma [Na], [K] and [Cl] remained stable at all swimming regimes. Expression of genes controlling energy metabolism and growth (IGF-I axis, cytochrome oxidase) and stress response (cortisol receptor, heat shock protein 70) revealed clear regulatory roles as the mRNA transcript levels of IGF-I and growth hormone receptors in hepatic tissue were up-regulated in fish exercised for 3-4 weeks at 2.5 BL/s. Oxygen consumption rate and swimming performance (U) for each experimental group were evaluated in parallel in Blazka-type swim-tunnels (3.9 L) and showed no training effect while prolonged swimming at 1.5 and 2.5 BL/s facilitated ammonia excretion and prevented build-up of plasma ammonia. Overall, these data suggest that sustained exercise at 2.5 BL/s enhanced growth and physiological fitness without compromising energy metabolism or ion-regulation. Our study provides a prospective of implementing exercise as a tool to increase fish production efficiency in commercial aquaculture systems.

Diet and Exercise Modulate GH-IGFs Axis, Proteolytic Markers and Myogenic Regulatory Factors in Juveniles of Gilthead Sea Bream (Sparus aurata)

“…Somatic growth in vertebrates is mainly regulated by the hypothalamic-pituitary axis through the growth hormone (GH) and the insulin-like growth factors (IGFs) system [ 17 ], and many authors reviewed its role in fish species [ 18 , 19 , 20 , 21 ]. In gilthead sea bream, changes in the GH-IGFs axis were studied through the seasonal cycle [ 22 ], life stages [ 23 ], nutritional status [ 24 , 25 ], as a response to environmental factors [ 26 , 27 ], or even after several weeks of sustained exercise [ 14 , 28 ]. All these works highlighted the important regulatory functions of those endocrine factors in this species.…”

Aerobic swimming in intensive finfish aquaculture: applications for production, mitigation and selection

“…This, of course, implies progressively reduced feed efficiency and FCR as swimming speed increases (Kiessling et al, 1994(Kiessling et al, , 2005Khan et al, 2014;Skov et al, 2015; Table 1). It is conceivable, nonetheless, that FCR and growth 'efficiency' are improved in exercised fish compared with those held in still water (Christiansen & Jobling, 1990;Jobling et al, 1993;Shrivastava et al, 2018). Swimming exercise at moderate levels appears to stimulate various regulatory factors that affect feed intake or growth, such as the expression of growth hormone (GH) and insulin-like growth factor-1 (IGF-1) (Barrett & McKeown, 1988;Blasco et al, 2015;Shrivastava et al, 2018) as well as expression of various genes associated with growth processes (Palstra et al, 2010b).…”

“…Although it is frequently reported that fish submitted to moderate swimming exercise have higher growth rates than those held in still water or at low currents (e.g. Ibarz et al, 2011; Palstra et al, 2015; Shrivastava et al, 2018), other studies have found that swimming exercise has no, or even negative, effects on growth (e.g. Kiessling et al, 1994; McKenzie et al, 2012; Skov et al, 2015).…”

Innate Immune Responses of Skin Mucosa in Common Carp (Cyprinus Carpio) Fed a Diet Supplemented with Galactooligosaccharides

“…Reference genes for the relative gene expression analysis were selected based on a two-step selection process. First, the related literature was studied to pinpoint the relevant panel of reference genes for carp [24,[33][34][35]. Second, the RT-qPCR analysis was performed on a full set of cDNA samples to determine the reference genes' quality and stability in the samples from skin mucosa.…”