Most types of pond fish that are kept in the UK are distantly (or more closely) related to the common carp and are used to the various climatic conditions that the UK is famous for.

Unlike mammals, fish are cold blooded which means that they have a body temperature that is affected by their local environment i.e. the water temperature. While mammals keep a constant body temperature, fish do not. If the water temperature is warm the fish will be warmer and hence more active and likely to need to feed more. When the water temperature is cold, their metabolism slows down and hence they become slower in their actions and hence do not need feeding as much.

Your pond fish will realise that the onset of winter is approaching and will adjust their behaviour accordingly. The subtle changes in water temperature during the late summer and early autumn months will lead to them storing sufficient energy to last the winter months without needing to feed. When the temperature of your pond drops below an average figure of around 7°C the fish will actually show little activity at all and will be unlikely to need to feed again until the temperature rises in the spring