Resting metabolic rate and growth performance in Qingbo (Spinibarbus sinensis) with different body weight

In order to investigate the differences of the energy metabolism and growth capacity of Qingbo (Spinibarbus sinensis) with different bogy mass, the resting metabolic rate (RMR) of this kind of fish with different body mass (10, 20, 40, 100 and 180 g groups) was firstly detected. After a 28-day feeding trial, the specific growth rate (SGR), feeding rate (FR) and the feed efficiency (FE) were tested in these groups as well. On the one hand, the RMR of S. sinensis was significantly increased with the increase of body mass, however, the RMR of unit weight was significantly decreased. Meanwhile, both SGR and FR were significantly increased, while the FE was indistinctly affected, and plasma GH hormone content was significantly negatively correlated with body mass (r = −0.753, n = 30). On the other hand, the RMR of unit mass was significantly positively correlated with SGR (r = 0.586, n = 51) and FR (r = 0.640, n = 51,), however insignificantly correlated with FE (r = 0.100, n = 51). The SGR was positively correlated with both FR (r = 0.956, n = 51) and FE (r = 0.447, n = 30), and the relation between FR and FE was not significantly correlated (r = 0.245, n = 30). All the information above suggested that, smaller S. sinensis can keep higher maintenance energy consumption and growth capacity, and this may be due to their higher digestive and assimilating ability.