Gill Remodeling in Crucian Carp during Sustained Exercise and the Effect on Subsequent Swimming Performance

AbstractGill remodeling can be extensive in crucian carp, where up to a 7.5-fold increase in gill surface area has been observed during exposure to hypoxia through a reduction in the interlamellar cell mass (ILCM) and increased lamellar protrusion that has been hypothesized to be signaled by the need to maximize oxygen uptake under a given condition. Sustained aerobic exercise may have the greatest influence on oxygen demand in fish; however, its effect on gill remodeling in crucian carp has not been investigated. The specific objectives of this study were to determine (i) whether sustained aerobic exercise induces gill remodeling in the crucian carp, (ii) whether gill remodeling following sustained exercise affects the maximum critical swimming speed (Ucrit) and maximal oxygen consumption rate (), and (iii) whether gill remodeling following sustained exercise is associated with trade-offs related to ionoregulation. We measured in crucian carp at each step during an initial Ucrit test (Ucrit1), forced the...