摘要：Daily food consumption was estimated over 30 successive days in summer for bluegill (Lepomis macrochirus) in a 13 ha impoundment, and simultaneously for green sunfish (Lepomis cyanellus) in a second-order mid-Missouri stream from the same watershed. Using temperature data from the Sanborn Field Station for the same period, a relationship between daily food consumption rate of the two fish species and synoptic-scale weather patterns or cycles was established using cross spectral analysis which is not found in the previous literature. Previous analyses of the two species in their respective aquatic environments showed that their daily consumption rates over 30-day periods were rhythmic and peaked on a time scale of 2 and 14 days. A spectral analysis of the temperature data from that period showed that there were statistically significant temperature variations on the time scale of 2, 6, and 15 days. The latter two periods are related to well-known synoptic meteorological rhythms (the passage of cyclones and large-scale vacillation in the jet stream). This same technique, method of cycles, when applied to the fishes’ consumption rate data showed that the spectral peaks occurred similar to those in the temperature analysis. Then, a similar analysis was performed on data taken from a 6-month feed study in another part of the world (Finland), in order to determine whether our results were robust. This result was positive as well. Thus, it is hypothesized here that the food consumption patterns of these two fishes are linked to variations in the local synoptic and large-scale weather conditions.
