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Electric discharges of two species of stargazers from the South China Sea (Uranoscopidae, Perciformes)


Experimentally, the specialized electrogenerative activity is discovered in two representatives of the family Uranoscopidae (Uranoscopus bicinctus and U. affinis) living in the coastal zone of Nha Trang Bay of the South China Sea (Vietnam). For the first time, the electric discharges of duration up to 100 ms are recorded in U. bicinctus and up to 300 ms in U. affinis. The discharges are monopolar oscillations of the potential with electronegativity in the area of the fish head. Distribution of potentials on the body surface of the stargazer was investigated. It is shown that the electric field during the discharge has dipole characteristics and the zone of the “null” equipotential is situated in the area of the soft dorsal fin. Electrophysiological experiments, using the method of microelectrode stimulation of different regions of the brain, demonstrated that stable electric discharges are caused by stimulation of the medial zone of the bottom of the fourth ventricle in medulla oblongata. The discharges caused in such way are fully analogous to those generated spontaneously and under mechanical stimulation of the skin. Thus, the conclusion could be made on localization of the stargazer’s electromotor center in this zone.

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  1. 1.

    J. A. Alves-Gomes, G. Orti, M. Haygood, and W. Heiligenberg, “Phylogenetic Analysis of the South American Electric Fishes (Order Gymnotiformes) and the Evolution of Their Electric System: A Synthesis Based on Morphology, Electrophysiology, and Mitochondrial Sequence Data,” Mol. Biol. Evol. 12, 298–318 (1995).

    CAS  PubMed  Google Scholar 

  2. 2.

    V. D. Baron, Electrogenerator Systems in Fish: Evolution and Mechanisms of Adaptation (Nauka, Moscow, 1982) [in Russian].

    Google Scholar 

  3. 3.

    V. D. Baron and J. A. Labas, “’Electromimicry,’ a Special Type of Imitation Behaviour in Fish?, in Proc. of the 1st Neuroetholog. Congr.(Abstracts) (Tokyo, 1986), p.112

  4. 4.

    V. D. Baron and N. A. Mikhailenko, “Uranoscopus scaber, A Transitional Form in the Evolution of Electric Organs in Fish,” Dokl. Biol. Sci. 265, 290–293 (1976).

    Google Scholar 

  5. 5.

    V. D. Baron and K. S. Morshnev, “Characteristics of Electrogeneration in Two African Species of Synodontidae (Mochokidae, Siluriformes),” Dokl. Biol. Sci. 361, 301–303 (1998).

    Google Scholar 

  6. 6.

    V. D. Baron and V. M. Olshansky, “Monopolar Electric Discharges of the Catfish Parasilurus asotus (Siluridae, Siluriformes),” J. Ichthyol. 49(5), 403–408 (2009).

    Article  Google Scholar 

  7. 7.

    V. D. Baron, K. S. Morshnev, V. M. Olshansky, and A. A. Orlov, “Electric Otgan Discharges of Two Species of African Catfish (Synodontis) during Social Behaviour,” Anim.Behav. 48, 1472–1475 (1994a).

    Article  Google Scholar 

  8. 8.

    V. D. Baron and K. S. Morshnev, “Characteristics of Electrogeneration in Two African Species of Synodontidae (Mochokidae, Siluriformes),” Dokl. Biol. Sci. 361, 301–303 (1994b).

    Google Scholar 

  9. 9.

    V. D. Baron, A. A. Orlov, and D. E. El’yashev, “Investigations of Electric and Acoustic Activity of Some Representatives of the Ichthyofauna of South Vietnam,” J. Ichthyol. 45(Suppl. 2), S271–S279 (2005).

    Google Scholar 

  10. 10.

    V. D. Baron, A. A. Orlov A. A., and A. S. Golubtsov, “Electric Discharges of the African Catfishes Clarias anguillaris and Heterobranchus longifilis,” Dokl. Biol. Sci. 418, 34–36 (2008).

    Google Scholar 

  11. 11.

    M. V. Bennett, “Electric Organs, in Fish Physiology,” Ed. by W. S. Hoar and D. J Randall (Acad. Press, N.Y., 1971), Vol. 5, pp. 347–491.

    Google Scholar 

  12. 12.

    B. O. Bratton and J. L. Ajers, “Observations on the Electric Organ Discharge of Two Skate Species (Chondrichthies: Rajidae) and Its Relationionship to Behavior,” Env. Biol. Fishes 20(4), 241–254 (1987).

    Google Scholar 

  13. 13.

    T. E. Finger, “Electroreception in Catfish: Behavior, Anatomy and Electrophysiology,” in Electroreception, Ed. by T. H. Bullock and W. Heiligenberg (John Wiley and Sons, N.Y., 1986), pp. 287–317.

    Google Scholar 

  14. 14.

    M. Hagedorn, M. Womble, and T. E. Finger, “Synodontid Catfish: A New Group of Weakly Electric Fish,” in Behavior and Anatomy, Brain Behav. Evol. 35, 268–277 (1990).

    Article  CAS  Google Scholar 

  15. 15.

    Yu. A. Labas and E. N. Glukhova, “Mechanisms of Widening and Change of Biological Functions in Phylogenesis with Reference to Specialized Electrogenerator Tissues in Fish,” Zh. Obshch. Biol. 42(5), 510–526 (1973).

    Google Scholar 

  16. 16.

    S. Lavoué, R. Bigorne, G. Lecointre, and J. F. Agnese, “Phylogenetic Relationships of Electric Fishes (Mormyridae: Teleostei) Inferred from Cytochrome b Sequences,” Mol. Phylogenet. Evol. 14, 1–10 (2000).

    Article  PubMed  Google Scholar 

  17. 17.

    N. A. Mikhailenko, “On the Biological Importance and Dynamics of Electric Discharges in Weakly Electric Fish of the Black Sea,” Zool. Zh. 40(9), 1347–1372 (1971).

    Google Scholar 

  18. 18.

    N. A. Mikhailenko, “Organ of Sound Generation and Electric Generation in the Black Sea Uranossorus scaber (Uranossoridae),” Zool. Zh. 42(9), 1353–1359 (1973).

    Google Scholar 

  19. 19.

    P. Moller, Electric Fishes: History and Behavior (Chapman Hall, London, 1995).

  20. 20.

    K. S. Mortshnev and V. M. Ol’shanskii, “Electric Discharges in Asian Catfish Ompok bimaculatus (Siluriidae),” Dokl. Biol. Sci. 354, 270–272 (1997).

    Google Scholar 

  21. 21.

    J. G. New, “Electric Organ Discharge and Electrosensory Reafference in Skates,” Biol. Bull. 187, 64–75 (1994).

    Article  CAS  PubMed  Google Scholar 

  22. 22.

    V. M. Ol’shanskii, K. S. Morshnev, A. M. Naseka, and Nguen Thi Nga, “Electric Discharges of Clarid Catfishes Cultivated in South Vietnam,” Vopr. Ikhtiol. 42(4), 549–557 (2002) [J. Ichthyol. 42 (6), 477–484 (2002)].

    Google Scholar 

  23. 23.

    P. Stoddard, “Predation Enhances Complexity in the Evolution of Electric Fish Signals,” Nature 400, 254–256 (1999).

    Article  CAS  PubMed  Google Scholar 

  24. 24.

    G. K. H. Zupanc and T. H. Bullock, “From Electrogenesis to Electroreception,” in Springer Handbook of Auditory Research, Electroreception, Ed. by T. H. Bullock, C. D. Hopkins, A. N. Popper, and R. R. Fay (Springer, New York, 2005), Vol. 21, pp. 5–46.

    Google Scholar 

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Baron, V.D. Electric discharges of two species of stargazers from the South China Sea (Uranoscopidae, Perciformes). J. Ichthyol. 49, 1065 (2009).

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Key words

  • stargazers
  • electrogeneration
  • electromotor centers