blindfish
Sightless cave dweller
A blindfish is any of several small fish species that have lost functional eyes through evolution, typically found in caves, underground streams, or other lightless environments.
The Mexican tetra and various cavefish are common examples.
Their ancestors had normal vision, but generations in total darkness made eyes unnecessary: The blindfish navigated by sensing water pressure changes.
Eyeless aquatic cave dweller
- subterraneanBeneath earth's surface
- karstEroded soluble rock terrain
- limestoneCarbonate sedimentary rock
- cavernLarge natural underground chamber
grotto · speleology · underground · aquifer · sinkhole · hypogean · darkness · chamber
Unable to perceive visually
- eyelessLacking organs of vision
- unpigmentedWithout coloring matter
- translucentPermitting diffused light passage
- vestigialReduced, without current function
regressed · pale · colorless · albino · depigmented · atrophied · white · ghostly
Changed through successive generations
- specializedAdapted for particular function
- sensoryRelated to perception
- survivalRemaining alive against odds
- isolationComplete separation from others
endemic · relict · phenotype · regressive · loss · mutation · fitness · chemoreception
At risk of extinction
- endemicNative to one area
- vulnerableOpen to attack
- protectedKept from harm
- scarceIn short supply
uncommon · limited · fragile · threatened · sensitive · conservation · habitat loss · pollution
cavefish
Eyeless aquatic cave dweller
- subterraneanBeneath earth's surface
- karstEroded soluble rock terrain
- limestoneCarbonate sedimentary rock
cavern · grotto · speleology · underground · aquifer · sinkhole · hypogean · darkness · chamber · stalactites
sightless
Unable to perceive visually
- eyelessLacking organs of vision
- unpigmentedWithout coloring matter
- translucentPermitting diffused light passage
vestigial · regressed · pale · colorless · albino · depigmented · atrophied · white · ghostly
evolved
Changed through successive generations
- specializedAdapted for particular function
- sensoryRelated to perception
- survivalRemaining alive against odds
isolation · endemic · relict · phenotype · regressive · loss · mutation · fitness · chemoreception · vibration
endangered
At risk of extinction
- endemicNative to one area
- vulnerableOpen to attack
- protectedKept from harm
scarce · uncommon · limited · fragile · threatened · sensitive · conservation · habitat loss · pollution · groundwater depletion