Academic freedom and the discovery of electroreception in catfish and dogfish

Abstract

A brief sketch is given of the changing interpretation of Academic Freedom at the universities in Th e Netherlands during the last half of the twentieth century, by discussing the discoveries of electroreception in catfi sh, Ameiurus nebulosus , and dogfi sh, Scyliorhinus canicula . It is concluded that science is no longer hypothesis-driven, but money-driven. Whereas innovation and discoveries belong typically to the domain of the individual scientist and fl ourish in a bottom-up organisation, the funding agencies of today advocate a top-down approach to stimulate creativity. Apparently the resultant institutionalization has not the desired result. Could electroreception research be initiated in 2008?Th e scene is a University in the Netherlands. Th e year is 2008. Th e discipline is biology. A student 1 wants to learn more about a particular type of behaviour he has noticed when he was visiting a marine aquarium during a stay abroad. Th is particular type of behaviour was that a dogfi sh, Scyliorhinus canicula, turned away its head when the animal keeper tried to feed it by putting a piece of squid on a rusty piece of iron wire in the vicinity of its head. Th e remarkable thing was that turning away its head did not occur when the piece of squid was off ered on a glass rod. Th e student went to see the 1) Persons of either gender will be referred to as "he". Preface

Frequency-dependent avoidance movement of glass catfish in response to sinusoidal electrical stimulation and associated spiking patterns of electroreceptors

“…Since the electrode distance was wider than the fish's body length, the glass catfish did not recognize the electric field as prey. Peters et al (2001) , while declining to say that the data were unpublished, reported that small weak dipole sources with 1 Hz are attractive, whereas large strong dipoles with 10 Hz are repulsive. Different sizes of dipoles potentially induce different behavior in glass catfish.…”

“…Thus, we believe that the avoidance movements of glass catfish in response to electrical stimulation are associated with the detection of large predators. Since there are other fish with similar electrosensory frequency characteristics ( Asano and Hanyu, 1986 ; Peters et al, 2001 ), a large dipole distance potentially induces avoidance behavior.…”

Evolution of the visual system in ray-finned fishes

“…Many groups are also known to communicate with sound (Parmentier & Diogo, 2006 ; Bass et al, 2015 ; Rice et al, 2022 ). In addition, all catfish have passive electroreceptors (Finger, 1986 ; Peters, 2008 ) and have also an extensive taste system covering the entire body surface (Finger, 1976 ). The taste pathways are known to reach the IL via the secondary gustatory nucleus (Kanwal et al, 1988 ).…”