THE EFFECT OF ENVIRONMENTAL FACTORS ON COMMUNICATION AND SPACING IN WEAKLY ELECTRIC FISH.
Item
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Title
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THE EFFECT OF ENVIRONMENTAL FACTORS ON COMMUNICATION AND SPACING IN WEAKLY ELECTRIC FISH.
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Identifier
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AAI8203331
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identifier
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8203331
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Creator
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SQUIRE, ANN ODMARK.
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Contributor
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Peter Moller
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Date
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1981
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Language
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English
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Publisher
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City University of New York.
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Subject
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Psychology, Psychobiology
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Abstract
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African mormyriform fish emit weak electric organ discharges which play an important role in the fishes' social and non-social behaviors. The biologically effective range of such an electrocommunication system is determined in part by physio-chemical properties of the environment. These experiments examined the effects of changes in water conductivity on electrocommunication and spacing behaviors in the weakly electric mormyrid Brienomyrus niger.;In Part I, I used an electric organ discharge display which typically occurs in social encounters between mormyrids--temporary discharge cessation--to investigate the range of electrocommunication under different water conductivity conditions. An individual fish was confined to a porous ceramic shelter tube and moved from a starting distance of 380 cm toward a similarly confined conspecific until discharge cessation occurred. The moved fish was subsequently returned to its original position. Water conductivity affected the peak-to-peak source voltage of the electric organ and the sensitivity of the fish's electroreceptors. As water conductivity was raised within a range of 10 to 36000 (mu)S/cm, the peak-to-peak amplitude of the electric organ discharge declined as a power function. The interfish distance at which discharge cessation occurred also decreased as conductivity was increased. Orientation of the shelter tubes affected discharge cessation distance, with large distances recorded when the tubes were oriented parallel to each other.;As a fish was moved away from its conspecific, the "silent" fish resumed discharging with a high-frequency rebound, which occasionally effected changes in the other fish's discharge activity at distances exceeding those associated with the initial discharge cessation.;In Part II, the effects of group size and water conductivity on spacing in free-swimming fish were investigated in two experiments. A group of fish was placed into a circular tank and photographed from above. Nearest neighbor distances were then calculated among members of the group.;The results of Experiment 1 indicated that the greater the number of fish in a group, the smaller the mean nearest neighbor distance among the group members.;In Experiment 2, changes in water conductivity had a negligible effect on nearest neighbor distances among members of groups of four fish. It is suggested that while water conductivity can affect the behavior of electric fish, the extent of conductivity's influence on mormyrid behavior in the natural habitat remains to be investigated.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
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Program
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Psychology
