Conference Paper
Analysis of startle responses in A. mexicanus reveals possible effects of diminished predation
Paz, A., McDole, B., Duboue, E. and Keene, A.C.
Record Number:
4293
Year:
2019
Journal:
AIM 2019
Pages:
44
Abstract:
Anti-predator adaptations are essential for the survival of many organisms. The c-start response
is a common escape reflex that has been characterized in a variety of fish. Despite the extensive
work done characterizing the responses of different species, little is known about the evolution of
this behavior. The teleost Astyanax mexicanus consists of ancestral surface-dwelling populations,
as well as divergent cave populations. While the surface populations experience predation, no
macroscopic predators have been identified for the cave populations. Here, we elicit c-bend startle
responses using vibrational stimuli to assess responsiveness of cave and surface fish larvae, and
conduct kinematic analyses to assess differences in latency, angular speed, and bend angle.
Though there was no observed difference in responsiveness, cavefish larvae exhibit longer
latency and slower angular speed than surface fish larvae. C-bend responses are often driven by
activation of a pair of reticulospinal neurons responsible for c-bend responses, the Mauthner
neurons, which integrates information from various sensory modalities, including sight. To assess
the light-dependence of this response, surface fish were also tested in the presence and absence
of white light. No differences were detected in responsiveness between light and dark conditions.
Taken together, these data reveal evolved differences in escape behavior between surface and
cave populations of A. mexicanus, which may be influenced by differences in predation.
Times Cited:
1
Conference Name:
Astyanax Interrnational Meeting
Relevent Species: