Effects of Fluctuating, Sublethal Applications of Heavy Metal Solutions Upon the Gill Ventilation Response of Bluegills (Lepomis macrochirus)

摘要

The ventilatory response of the bluegill to fluctuating, sublethal amounts of heavy metals was investigated. Non-contact submerged, stainless steel electrodes were used to detect the weak electrical potentials that are produced when fish ventilate their gills. These signals were amplified using high-gain amplifiers which were interfaced with a minicomputer. These ventilatory data were accumulated continuously, and both the ventilatory rates and average signal amplitude were recorded on electronic tape for later analysis. The response to these toxic solutions was an increase in rate as well as a decrease in signal amplitude. The latter response was shown to be a real response of the fish and not due to changes in the electrical properties of the water when toxicant was added. Due to the extreme smoothing of the data, the analysis of variance was unable to detect any differences between the toxicant application patterns. It was significant to note, however, that the fish were capable of reacting to each subsequent pulse of toxicant in a similar manner.