A lopsided face helps this eyeless cave fish navigate

Science ◽  
2019 ◽  
Author(s):  
Elizabeth Pennisi
Keyword(s):  
Cave Fish

scholarly journals The Molecular Genetics and Evolution of Red and Green Color Vision in Vertebrates

Genetics ◽  
2001 ◽  
Vol 158 (4) ◽  
pp. 1697-1710 ◽  
Author(s):  
Shozo Yokoyama ◽  
F Bernhard Radlwimmer
Keyword(s):  
Color Vision ◽  
Homo Sapiens ◽  
Amino Acid Sequences ◽  
Capra Hircus ◽  
Sciurus Carolinensis ◽  
Cave Fish ◽  
Vitro Assay ◽  
Green Color ◽  
Astyanax Fasciatus

Abstract To better understand the evolution of red-green color vision in vertebrates, we inferred the amino acid sequences of the ancestral pigments of 11 selected visual pigments: the LWS pigments of cave fish (Astyanax fasciatus), frog (Xenopus laevis), chicken (Gallus gallus), chameleon (Anolis carolinensis), goat (Capra hircus), and human (Homo sapiens); and the MWS pigments of cave fish, gecko (Gekko gekko), mouse (Mus musculus), squirrel (Sciurus carolinensis), and human. We constructed these ancestral pigments by introducing the necessary mutations into contemporary pigments and evaluated their absorption spectra using an in vitro assay. The results show that the common ancestor of vertebrates and most other ancestors had LWS pigments. Multiple regression analyses of ancestral and contemporary MWS and LWS pigments show that single mutations S180A, H197Y, Y277F, T285A, A308S, and double mutations S180A/H197Y shift the λmax of the pigments by −7, −28, −8, −15, −27, and 11 nm, respectively. It is most likely that this “five-sites” rule is the molecular basis of spectral tuning in the MWS and LWS pigments during vertebrate evolution.

BLIND MEXICAN CAVE FISH (ASTYANAX HUBBSI) RESPOND TO MOVING VISUAL STIMULI

1994 ◽  
Vol 188 (1) ◽  
pp. 89-101 ◽  
Author(s):  
T Teyke ◽  
S Schaerer
Keyword(s):  
Visual Stimulus ◽  
Swimming Velocity ◽  
Environmental Cues ◽  
Cave Fish ◽  
Optomotor Response ◽  
Aquarium Fish ◽  
Modified Theory ◽  
Test Aquarium ◽  
Optomotor Behaviour

In apparatus for measuring optomotor behaviour, blind Mexican cave fish, Astyanax hubbsi, increase their swimming velocity upon rotation of a striped cylinder, i.e. in response to a solely visual stimulus. The fish follow the movements of the stripes at (i) rotation velocities between 60 degrees s-1 and 80 degrees s-1, (ii) light intensities of less than 20 lx and, (iii) stimulus widths subtending an angle of less than 1 °. Extirpation of the vestigial eye structures does not affect the response to the moving visual stimulus, which indicates that the response is mediated by extra-ocular photoreceptors. An optomotor response can be reliably evoked in a round test aquarium. Fish do not respond when the test aquarium contains environmental cues, such as bars on the wall or when a section of the round aquarium is divided off. This indicates that the fish obtain information about their environment from different sensory sources and that the visual stimulus is effective only when no other means of orientation are available. We suggest a modified theory of the optomotor response, which emphasizes the crucial role of the environment in eliciting the response and which permits behaviours more complex than just following the stimulus.

Regressive and Constructive Traits in Astyanax Surface and Cave Fish

2017 ◽  
pp. 79-189
Author(s):  
Horst Wilkens ◽  
Ulrike Strecker
Keyword(s):  
Cave Fish
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