Comparison of the jamming avoidance responses in Gymnotoid and Gymnarchid electric fish: A case of convergent evolution of behavior and its sensory basis
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A behavioral response conforming to defining features of the jamming avoidance response (JAR) previously reported inEigenmannia andApteronotus of the Cypriniformes is found inGymnarchus of the Mormyriformes.
Other parallel specializations of these groups are noted, of which the most relevant is the character of the electric organ discharge (EOD); it is quasisinusoidal, high in repetition rate and highly regular in each of the genera. The same features are found inSternopygus but it lacks a JAR.
The EOD is compared inGymnarchus, Eigenmannia, Apteronotus andSternopygus, in respect to power spectrum and regularity.
Other special features of the EOD inGymnarchus are described, including “singing” and a miniature EOD of a different frequency from the main EOD.
The JAR inGymnarchus, compared toEigenmannia andApteronotus is longer in latency, slower in reaching plateau, smaller in maximum frequency shift and best excited by a stimulus frequency closer to its own. The voltage gradient threshold (≪2.5μV/cm) is higher and the dynamic range smaller. Some correlations with habit of life are suggested.
Two types of electroreceptors seem particularly relevant to the JAR. They are similar to the T and P units already reported inEigenmannia but substantial differences require separate designations; we call them Type S and Type O units.
Type S units are like T units but spontaneous at high rates and phase coding over a limited intensity range near threshold. Over a wide range of intensity, including much of the physiological range normally encountered the S unit cannot encode intensity.
Type O units are like P units but usefully coding in a narrow intensity range; they are often unable to reach 1∶1 following. The threshold is usually about 20 db higher than in S units.
The filter properties of both types are those of a bandpass filter. Whereas the O units are sharply tuned to the EOD frequency, the S units have a flat passband over a range of about 150 Hz, and sharp cutoffs (about 50 db/octave) on both the high and low frequency sides.
KeywordsBandpass Filter Intensity Range Stimulus Frequency Convergent Evolution Electric Organ Discharge
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- Bennett, M. V. L.: Comparative physiology: electric organs. Ann. Rev. Physiol.32, 471–528 (1970)Google Scholar
- Bennett, M. V. L.: Electroreception. In: Fish physiology (W. S. Hoar, D.J. Randall, eds.), p. 493–574. Berlin-Heidelberg-New York: Academic Press 1971Google Scholar
- Bullock, T. H.: Species differences in effect of electroreceptor input on electric organ pacemakers and other aspects of behavior in electric fish. Brain Behav. Evol.2, 85–118 (1969)Google Scholar
- Bullock, T. H., Hamstra, R. H., Jr., Scheich, H.: The jamming avoidance response of high frequency electric fish. I. General features. J. comp. Physiol.77, 1–22 (1972)Google Scholar
- Bullock, T. H., Hamstra, R. H., Jr., Scheich, H.: The jamming avoidance response of high frequency electric fish. II. Quantitative aspects. J. comp. Physiol.77, 23–48 (1972)Google Scholar
- Erskine, E. T., Howe, D. W., Weed, B. C.: The discharge period of the weakly electric fishSternarchus albifrons. Amer. Zool.6, 521 (Abs.) (1966)Google Scholar
- Heiligenberg, W.: Electrolocation of objects in the electric fishEigenmannia (Rhamphichthyidae, Gymnotoidei). J. comp. Physiol.87, 137–164 (1973)Google Scholar
- Heiligenberg, W.: Electrolocation and jamming avoidance in aHypopygw (Rhamphichthyidae, Gymnotoidei) an electric fish with pulse-type discharge. J. comp. Physiol.91, 223–240 (1974)Google Scholar
- Heiligenberg, W.: Electrolocation and jamming avoidance in the electric fishGymnarchus niloticus (Gymnarchidae, Mormyriformes). J. comp. Physiol.103, 55–67 (1975)Google Scholar
- Hopkins, C. D.: Sex differences in electric signaling in an electric fish. Science176, 1035–1037 (1972a)Google Scholar
- Hopkins, C. D.: Patterns of electrical communication among gymnotid fish. Doctoral Dissertation, The Rockefeller University, New York (1972b)Google Scholar
- Hopkins, C. D.: Electric communication: functions in the social behavior ofEigenmannia virescens. Behaviour50, 270–306 (1974b)Google Scholar
- Kalmijn, A. J.: The second derivative or potential mode? A critical evaluation of Lissmann and Machin's theory concerning the mode of operation in the electroreceptors ofGymnarchus niloticus and similar fish. S.I.O. Technical Rpt. No. 72-69, University of California, San Diego (1972)Google Scholar
- Kalmijn, A.J.: Electro-orientation in sharks and rays: theory and experimental evidence. S.I.O. Technical Rpt. No. 73-39, University of California, San Diego (1973)Google Scholar
- Kalmijn, A.J.: The detection of electric field from inanimate and animate sources other than electric organs. In: Electroreceptors and other specialized receptors in lower vertebrates. Handbook of sensory physiology, vol. III/3 (A. Fessard, ed.), p. 147–200. Berlin-Heidelberg-New York: Springer 1974Google Scholar
- Knudsen, E. I.: Spatial aspects of the electric fields generated by weakly electric fish. J. comp. Physiol.99, 103–118 (1975)Google Scholar
- Lissmann, H.W.: On the function and evolution of electric organs in fish. J. exp. Biol.35, 156–191 (1958)Google Scholar
- Lissmann, H. W., Machin, K. E.: The mechanism of object location inGymnarchus niloticus and similar fish. J. exp. Biol.35, 451–486 (1958)Google Scholar
- Roth, A., Szabo, T.: The receptor potential and its functional relationship to the nerve impulse analyzed in a sense organ by means of thermal and electric stimuli. J. comp. Physiol.80, 285–308 (1972)Google Scholar
- Scheich, H., Bullock, T. H.: The detection of electric fields from electric organs. In: Electroreceptors and other specialized receptors in lower vertebrates. Handbook of sensory physiology, vol. III/3 (A. Fessard, ed.), p. 201–256. Berlin-Heidelberg-New York: Springer 1974Google Scholar
- Szabo, T.: Anatomo-physiologie des centres nerveux spécifiques de quelques organes électriques. In: Bioelectrogenesis (C. Chagas, A. Paes de Carvalho, eds.), p. 185–201. Amsterdam: Elsevier Publishing Co. 1961Google Scholar
- Szabo, T.: The activity of cutaneous sensory organs inGymnarchus niloticus. Life Sci.7, 285–286 (1962a)Google Scholar
- Szabo, T.: Spontaneous electrical activity of cutaneous receptors in mormyrids. Nature (Lond.)194, 600–601 (1962b)Google Scholar
- Szabo, T.: Anatomy of the specialized lateral line organs of electroreception. In: Electroreceptors and other specialized receptors in lower vertebrates. Handbook of sensory physiology, vol. III/3 (A. Fessard, ed.), p. 59–124. Berlin-Heidelberg-New York: Springer 1974Google Scholar
- Szabo, T., Enger, P. S.: Pacemaker activity of the medullary nucleus controlling electric organs in high-frequency gymnotid fish. Z. vergl. Physiol.49, 285–300 (1964)Google Scholar
- Thompson, R. F., Spencer, W. A.: Habituation: a model phenomenon for the study of neuronal substrates of behavior. Psychol. Rev.173, 16–43 (1966)Google Scholar
- Watanabe, A., Takeda, K.: The change of discharge frequency by A. C. stimulus in a weak electric fish. J. exp. Biol.40, 57–66 (1963)Google Scholar
- Westby, G. W. N.: Latency dependent response ofGymnotus carapo to discharge-triggered stimuli. A bearing on electric fish communication. J. comp. Physiol.96, 307–341 (1975)Google Scholar