easily accessible at the structural level. Chemical reactions in cells are influenced by such factors as temperature, substrates and oxygen delivery; cold adaptation permits polar fish to bypass the usually expected drop in biochemical reaction rates and maintain life systems when ambient temperatures drop in their habitat.
Changes in growth rates of polar fish are also variable, and probably related to cold-adaptation (8). In a study that examined complete energy budgets for Arctic cod (Boreadadus saida) at low temperatures, these authors suggest that growth rates in this polar fish mirror that of primary prey species of copepods, amphipods and capelin that themselves exhibit seasonal patterns, with consumption and respiration rates by the cod slowing at lower water temperatures. Metabolic rates at both the standard and active levels as well as oxygen consumption are probably impacted by exposure to frigid water (15).
Studies of the effects of freezing water on the growth of polar fish have yielded int
...