Hans Werner Lissmann

Hans Werner Lissmann (born April 30, 1909 in Nikolajew , Ukraine; † April 21, 1995 in Cambridge ) was a Russian-German-British zoologist. He is considered the discoverer of the electrolocation as the "sixth sense" that different fish species have.

Life and activity

Lissmann grew up in Tsarist Russia as the son of the German settler couple Robert and Ebba Lissmann. On the occasion of the outbreak of World War I, the family was deported to Siberia and interned there. In 1919 the family moved to Germany, where they settled in Hamburg in 1922.

In the late 1920s, Lissmann began studying biology at the University of Hamburg . He then worked under Jakob Johann von Uexküll at the Hamburg Institute for Environmental Research. He received his doctorate in 1932 with a thesis on Siamese fighting fish . In 1933 he was sent to the biological research station of the Hungarian Academy of Sciences on a travel grant. After he clashed there with the demands that the National Socialists, who had meanwhile come to power, made on his work, he emigrated.

Lissmann first ended up in India. There he received a scholarship from the Academic Assistance Council, which enabled him to go to Great Britain and take up a position in the research department of the Zoological Institute at Cambridge University under James Gray . His main research interests there were behavior, movement sequences, sensory organs and nervous systems of animals.

After his emigration, Lissmann was classified as an enemy of the state by the National Socialist police forces: In the spring of 1940 he was placed on the special wanted list by the Reich Security Main Office , a directory of people who would be followed by special commands by the occupying forces in the event of a successful invasion and occupation of the British island by the Wehrmacht The SS should enter the country, should be located and arrested with special priority.

In 1947, Lissmann was properly appointed as Assistant Director of the Research Department of the Cambridge Zoological Institute.

Lissmann's best-known scientific achievement came in 1950: on a visit to the London Zoo in 1949, he noticed that fish of the species Great Niloticus ( Gymnarchus niloticus ) were able to swim backwards and forwards at the same speed and with the same skill, agility and clarity of purpose without colliding with any obstacles behind them. This made him suspect that the great nil pike must have a "sixth" sense that is alien to humans and that he - since he observed something similar in the nearby electric eel aquarium - associated it with electricity. After a friend gave him a specimen of this fish species for his wedding, Lissmann researched it in detail in his laboratory: he put the fish in a tank and inserted electrodes into the aquarium. With these he succeeded in amplifying an electric field inherent in this fish - which is not noticeable to humans by mere touching - and then making this visible with the help of an oscilloscope. He concluded that this self-fabricated electrical field, with which the Great Nile pike constantly surrounds itself, provides it with information about its environment, which it uses to orient itself instinctively in its movements.

Through further experiments, Lissmann was able to provide practical evidence that the great nil pike uses its electric field for spatial orientation: If he held two ends of a U-shaped piece of conductive copper wire in the water near the fish, the fish fled. On the other hand, if he tried the same with non-conductive wire, the fish did not react. After he recorded the reactions of the fish and reproduced them in the tank with electrodes, the result was that the fish attacked the signals sent by the electrodes. So it reacted to the electronic stimuli in the same way as a fighting fish reacts to a mirror set into its aquarium by attacking its own reflection. This proved that the great nil pike has a sixth sense that deviates from the five human senses, the ability to generate electrical fields and perceive disturbances in them. The practical application of this ability consisted, as Lissmann explained, of locating and distinguishing objects - such as obstacles - as well as other fish (as prey or as enemies to be avoided) based on the perception of their conductivity and reacting to them accordingly (so can Prey animals are identified based on their own conductivity as organisms, while stones etc. to be avoided as dead objects have no conductivity and are thus recognized as an obstacle).

In 1954, Lissmann was elected a Fellow of the Royal Society .

In 1955 Lissmann was appointed lecturer ( Lecturer ) and 1966 professor ( Reader ) for experimental zoology at the University of Cambridge. In 1969 he was finally appointed head of the Animal Behavior Subdivision of the Zoological Institute, receiving the rank of director. In 1977 he retired.

family

Lissmann had been married to Corinne Foster-Barham since 1949, with whom he had a son.

Fonts

• The environment of the fighting fish (Betta splendens Regan) , 1932.
• "Posture and form of movement of a Myriopod in connection with its autotomy", in: Zeitschrift fürvergleichende Physiologie 21 (1935), pp. 751-766.
• “Continuous Electrical Signals from the Tail of a Fish, Gymnarchus Niloticus Cuv”, in: Nature , Vol. 167, No. 4240 (1951), pp. 201-202.
• "The Mechanism of Object Location in Gymnarchus Niloticus and Similiar Fish", in: Journal of Experimental Biology , Vol. 35 (1958), pp. 451-486. (in cooperation with Ken E. Machin)
• “The Mode of Operation of the Electric Receptors in Gymnarchus Niloticus.”, In: Journal of Experimental Biology 37, No. 4 (1960), pp. 801-811.
• "Electric Location by Fishes," in: Scientific American , Vol. 208, pp. 50-59, March 1963.
• "James Gray. October 14, 1891-14 December 197", in: Biographical Memoirs of Fellows of the Royal Society , Vol. 24 (1978), pp. 54-70.

literature

• Alexander R. McNeill: "Hans Werner Lissmann, April 30, 1909-21 April 1995.", in: Biographical Memoirs of Fellows of the Royal Society 42 (1996), pp. 234-45.

Individual evidence

1. ↑ Entry on Lissmann on the special wanted list GB (reproduction on the website of the Imperial War Museum in London)
2. ↑ OBITUARY: Hans Lissmann .