Journal Article
Extreme adaptation in caves
Soares, D. and Niemiller, M.L.
Record Number:
4596
Year:
2018
Journal:
The Anatomical Record
Pages:
15-23
Volume:
303
Abstract:
Cave adaptation leads to unique anatomical specializations in many taxonomic
groups. As the role of vision is reduced or disappears in a subterranean
environment, other specializations arise to allow the organism to successfully
detect and interact with their environment. A suite of unique, convergent phenotypes
associated with subterranean adaptation has emerged (termed troglomorphy),
with reduction or loss of pigmentation and eyes being the most
conspicuous. Two vertebrate groups that have successfully colonized and
adapted to subterranean environments are cavefishes and cave salamanders.
There are many shared troglomorphic anatomical characters shared between
these two groups, and we describe herein the morphological traits that are
unique to fishes and salamanders that are adapted to caves and other subterranean
habitats. Troglobionts, animals strictly bound and adapted to underground
habitats, are outcomes of not just regressive evolution, but also
constructive adaptation. There are skeletal changes, such as broadening and
flattening of the head, as well as hypertrophy of non-visual modalities. Cavefishes
and salamanders have lost eyes and pigmentation, but also enhanced
mechanosenzation, chemosenzation and, in some cases, electroreception. Both
cavefishes and cave salamanders have become important models in the study
of the ecology, behavior, and evolution of subterranean colonization and adaptation.
However, our knowledge is primarily limited to a few taxa and many
questions remain to be studied. Anat Rec, 303:15–23, 2020. © 2018 American
Association for Anatomy
Key words: adaptation; innovation; evolutionary
Times Cited:
0