Conference Paper
Olfactory capacities in blind cavefish
Rétaux, S., Bibliowicz, Y., Blin, M., Elipot, Y., Espinasa, L., Hinaux, H. and Tine, E.
Record Number:
4303
Year:
2019
Journal:
AIM 2019
Pages:
55
Abstract:
We use A. mexicanus cavefish to understand developmental, genetic and cellular mechanisms
involved in brain and behavioral evolution. We have particularly focused on the evolution of the
olfactory sensory system, by a comparative approach at several levels between cavefish and their
surface-dwelling conspecifics. First, we have assessed the olfactory capabilities of larvae and
adults of the two Astyanax morphs. Experiments performed in the lab in controlled conditions and
using amino-acids as olfactory cues show that Pachón cavefish have a much better olfactory
discrimination threshold than surface fish. Experiments performed inside the Subterráneo cave
(Mexico) show that cave morphs strongly respond to food-related olfactory cues and also to low
concentrations of amino-acids. This suggests that increased olfactory capacities have evolved
independently in two caves. In search for the origins of the outstanding olfactory capacities of
cavefish, we have then compared the development and the neuroanatomy of the olfactory
epithelium/organ in Pachón embryos and juveniles, we have manipulated its development, and
we have tested the impact of the lack of vision on olfactory capabilities. The results suggest that
the size and the neuronal composition of the olfactory epithelium, as well as some degree of
developmental plasticity of the olfactory system are responsible for the excellent cavefish
olfaction. Such a change in the cavefish olfactory sensory system can probably be considered as
adaptive in the extreme dark environment where cavefish live.
Times Cited:
1
Conference Name:
Astyanax Interrnational Meeting
Relevent Species: