Abstract
Bulldog fish (Marcusenius macrolepidotus) generate short (<1 ms) electric-organ discharges (EODs), separated by much longer and highly variable interdischarge intervals (IDIs). We observed overt behaviour and electrical activity during reproductive behaviour in a male and in a female bulldog, and identified IDI patterns with putative signal functions. In contrast to Pollimyrus adspersus and Pollimyrus isidori, in which an elaborate and extended courtship precedes spawning proper, our fish started spawning almost immediately when we allowed the female to enter the male’s territory. The male did not construct a nest, and neither parent provided parental care. The male showed very little aggression towards the intruding female. Fish spawned in bouts near the male’s hiding place, and eggs were scattered by the female’s vigorous tail flips as she left the spawning site, only to return shortly thereafter. During spawning bouts, both fish generated highly stereotyped IDI patterns: the male generated a series of IDIs gradually decreasing from about 200 ms to about 55 ms that was abruptly terminated by a long IDI. The female generated a series of relatively regular IDIs (about 54 ms) that was followed by a marked increase in IDI duration (the probable time of spawning). Finally, a sharp decrease in IDIs to about 20 ms accompanied the female’s sudden escape from the spawning site. In between spawning bouts, both fish generated series of very short IDIs (high discharge rate, HD) that alternated abruptly with very low-rate inter-HD activity (especially in the male). IDIs as short as 9 ms (male) or 11 ms (female) occurred during HD displays. No visible aggression, in fact very little overt behaviour, occurred during these HD displays in both fish. Agonistic interactions between male and female, outside a reproductive context, were similar to those previously described in male pairs, including overt behavioural patterns such as parallel swimming, antiparallel display and attack, as well as HD displays. When not interacting, fish did not generate HD displays. We suggest the HD display is a communication signal in both reproductive and agonistic contexts.
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References
Bass AH, Hopkins CD (1985) Hormonal control of sex differences in the electric organ discharge (EOD) of mormyrid fishes. J Comp Physiol A 156:587–604
Bauer R (1972) High electrical discharge frequency during aggressive behaviour in a mormyrid fish, Gnathonemus petersii. Experientia 28:669–670
Bauer R (1973) Electric organ discharge activity of resting and stimulated Gnathonemus petersii (Mormyridae). Behaviour 50:306–323
Bell CC, Myers JP, Russell CJ (1974) Electric organ discharge patterns during dominance related behavioral displays in Gnathonemus petersii (Mormyridae). J Comp Physiol 92:201–228
Birkholz J (1969) Zufällige Nachzucht bei Petrocephalus bovei. Aquarium 3:201–203
Bratton BO, Kramer B (1989) Patterns of the electric organ discharge during courtship and spawning in the mormyrid fish, Pollimyrus isidori. Behav Ecol Sociobiol 24:349–368
Curtis CC, Stoddard PK (2003) Mate preference in female electric fish, Brachyhypopomus pinnicaudatus. Anim Behav 66:329–336
FitzGerald GJ (1992) Filial cannibalism in fishes: why do parents eat their offspring? Trends Ecol Evol 7:7–10
Graff B (1989) Firing activity of the weakly electric fish Marcusenius macrolepidotus (Mormyridae, Teleostei): logarithmic repartition of inter-pulse intervals and sequential inequality testing. Behaviour 109:258–284
Hanika S, Kramer B (2005) Intra-male variability of its communication signal in the weakly electric fish, Marcusenius macrolepidotus, and its possible functions. Behaviour (in press)
Hopkins CD (1999) Design features for electric communication. J Exp Biol 202:1217–1228
Hopkins CD, Comfort NC, Bastian J, Bass AH (1990) Functional analysis of sexual dimorphism in an electric fish, Hypopomus pinnicaudatus, order Gymnotiformes. Brain Behav Evol 35:350–367
Kirschbaum F (1987) Reproduction and development of the weakly electric fish, Pollimyrus isidori (Mormyridae, Teleostei) in captivity. Environ Biol Fish 20:11–31
Kirschbaum F (1995) Reproduction and development in mormyriform and gymnotiform fishes. In: Moller P (ed) Electric fishes. History and behavior. Chapman & Hall, London, pp 267–302
Kramer B (1974) Electric organ discharge interaction during interspecific agonistic behaviour in freely swimming mormyrid fish. A method to evaluate two (or more) simultaneous time series of events with a digital analyser. J Comp Physiol 93:203–235
Kramer B (1976) Flight-associated discharge pattern in a weakly electric fish, Gnathonemus petersii (Mormyridae, Teleostei). Behaviour 59:88–95
Kramer B (1979) Electric and motor responses of the weakly electric fish, Gnathonemus petersii (Mormyridae), to play-back of social signals. Behav Ecol Sociobiol 6:67–69
Kramer B (1990a) Electrocommunication in teleost fishes: behavior and experiments. Springer, Berlin Heidelberg New York
Kramer B (1990b) Sexual signals in electric fish. Trends Ecol Evol 5:247–250
Kramer B (1996) Electroreception and communication in fishes. Gustav Fischer, Stuttgart
Kramer B (1997) A field study of African elephantfish (Mormyridae, Teleostei): electric organ discharges in Marcusenius macrolepidotus (Peters, 1852) and Petrocephalus catostoma (Günther, 1866) as related to sex. J Afr Zool 111:313–341
Kramer B, Bauer R (1976) Agonistic behaviour and electric signalling in a mormyrid fish, Gnathonemus petersii. Behav Ecol Sociobiol 1:45–61
Kramer B, Westby GWM (1985) No sex difference in the waveform of the pulse type electric fish, Gnathonemus petersii (Mormyridae). Experientia 41:1530–1531
Kramer B, van der Bank FH, Skelton PH (1998) Two new species of snoutfish (Mormyridae) from South Africa: evidence from electric organ discharges. In: African fishes and fisheries: diversity and utilisation (abstract). Paradi conference, Grahamstown, South Africa, p 50
Landsman RE, Moller P (1988) Testosterone changes the electric organ discharge and external morphology of the mormyrid fish Gnathonemus petersii Mormyriformes. Experientia 44:900–903
Lissmann HW (1958) On the function and evolution of electric organs in fish. J Exp Biol 35:156–191
Lissmann W (1961) Ecological studies on gymnotids. In: Chagas C, Paes de Carvalho A (eds) Bioelectrogenesis. Elsevier, Amsterdam, pp 215–226
Möhres FP (1957) Elektrische Entladungen im Dienste der Revierabgrenzung bei Fischen. Naturwissenschaften 44:431–432
Moller P (1995) Electric fishes. History and behavior. Chapman & Hall, London
Scheffel A, Kramer B (1997) Electrocommunication and social behaviour in Marcusenius senegalensis (Mormyridae, Teleostei). Ethology 103:404–420
Skelton P (2001) A complete guide to the freshwater fishes of southern Africa, 2nd edn. Struik, Cape Town
Squire A, Moller P (1982) Effects of water conductivity on electrocommunication in the weak-electric fish Brienomyrus niger (Mormyriformes). Anim Behav 30:375–382
Werneyer M, Kramer B (2002) Intraspecific agonistic interactions in freely swimming mormyrid fish, Marcusenius macrolepidotus (South African form). J Ethol 20:107–121 DOI 10.1007/s10164-002-0062-y
Acknowledgements
We wish to thank Dr. F.H. van der Bank (Rand Afrikaans University [now the University of Johannesburg, Kingsway Campus], RSA) and Dr. J. Engelbrecht (Mpumalanga Parks Board, RSA) for sampling and exporting our test fish from the field. The observations and experiments comply with the current laws of Germany. This work was supported by the Deutsche Forschungsgemeinschaft (DFG), grants Kr446/10-4 and Kr446/10-5.
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Werneyer, M., Kramer, B. Electric signalling and reproductive behaviour in a mormyrid fish, the bulldog Marcusenius macrolepidotus (South African form). J Ethol 23, 113–125 (2005). https://doi.org/10.1007/s10164-004-0136-0
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DOI: https://doi.org/10.1007/s10164-004-0136-0