Abstract
Whether fish are sentient beings remains an unresolved and controversial question. Among characteristics thought to reflect a low level of sentience in fish is an inability to showstress-induced hyperthermia (SIH), a transient rise in body
temperature shown in response to a variety of stressors. This is a real fever
response, so is often referred to as ‘emotional fever’. It has been suggested
that the capacity for emotional fever evolved only in amniotes (mammals,
birds and reptiles), in association with the evolution of consciousness in these
groups. According to this view, lack of emotional fever in fish reflects a lack
of consciousness. We report here on a study in which six zebrafish groups
with access to a temperature gradient were either left as undisturbed controls
or subjected to a short period of confinement. The results were striking: compared to controls, stressed zebrafish spent significantly more time at higher
temperatures, achieving an estimated rise in body temperature of about
2–48C. Thus, zebrafish clearly have the capacity to show emotional fever.
While the link between emotion and consciousness is still debated, this finding
removes a key argument for lack of consciousness in fish.
temperature shown in response to a variety of stressors. This is a real fever
response, so is often referred to as ‘emotional fever’. It has been suggested
that the capacity for emotional fever evolved only in amniotes (mammals,
birds and reptiles), in association with the evolution of consciousness in these
groups. According to this view, lack of emotional fever in fish reflects a lack
of consciousness. We report here on a study in which six zebrafish groups
with access to a temperature gradient were either left as undisturbed controls
or subjected to a short period of confinement. The results were striking: compared to controls, stressed zebrafish spent significantly more time at higher
temperatures, achieving an estimated rise in body temperature of about
2–48C. Thus, zebrafish clearly have the capacity to show emotional fever.
While the link between emotion and consciousness is still debated, this finding
removes a key argument for lack of consciousness in fish.
| Original language | English |
|---|---|
| Article number | 20152266 |
| Number of pages | 7 |
| Journal | Proceedings of the Royal Society B: Biological Sciences |
| Volume | 282 |
| Issue number | 1819 |
| Early online date | 25 Nov 2015 |
| DOIs | |
| Publication status | Published - Nov 2015 |
Bibliographical note
Date of Acceptance: 28/10/2015Keywords
- zebrafish
- ecthotherms
- fish welfare
- fish sentience
- emotional fever
- stress-induced hyperthermia
- consciousness