Conference Paper
Parallel trophic morphology in cave and surface fish Astyanax mexicanus (De Filippi 1853)
Hernández, J., Garita-Alvarado, C.A. and Ornelas-García, C.P.
Record Number:
4283
Year:
2019
Journal:
AIM 2019
Pages:
35
Abstract:
The association between morphological disparity and ecological segregation could be considered
a signal of divergent selection. Cavefish Astyanax mexicanus shows several constructive and
regressive features as adaptations to cave environments, however we lack an exhaustive analysis
of trophic morphology of Astyanax in contrasting environments (surface-cave). We characterized
the trophic morphology of Astyanax associated to contrasting environments and lineages (i.e. oldnew)
by means of geometric morphometric analysis of the premaxillary bone (n=107), principal
component analysis (PCA) of six ecomorphological measures (n=93) and the frequency of
maxillary teeth (n=84) of specimens from 20 populations (7 surface, 9 cave and 4 hybrid). Despite
of lineages, cavefish populations showed a parallel pattern of a wider premaxilla and a shorter
ascending process (contrastingly with surface fish morphology), while hybrid populations showed
intermediate forms between cave and surface fish. Similarly, the PCA of ecomorphological
measures showed disparity between cave and surface populations (longer snout, maxillary bone
and ascending process of premaxilla in surface populations) with intermediate forms in hybrid
populations. Finally, cavefish showed more maxillary teeth (2 to 5, mode 3) than surface fish (1
to 3, mode 1), while hybrid showed intermediate number (1 to 4, mode 2). The parallel patterns
of trophic morphology in Astyanax cavefish populations highlight how similar selective pressures
can shape similar phenotypes and increase the growing evidence of Astyanax as a model for
studying parallel evolution.
Times Cited:
1
Conference Name:
Astyanax Interrnational Meeting
Relevent Species: