Chapter 20: Vision Flashcards
In water, explain the spatial scale of senses.
HEARING: Furthest 1.6KM
SMELL: Chemical cues 0.5KM
VIBRATION SENSORS: Lateral Line 100M
SIGHT: Coral reef fish 25M
ELECTRICAL SENSORS: Ampullae of lorenzini -1 Meter
What sense has the greatest detection range?
Sound!
Describe the general morphology of fish eyes (be able to draw)
Similar to tetrapods
Light enters eye at cornea-> passes through pupil-> lens
Most fish have fixed pupil size due to protrude and nearly touches retina
CONES more focused higher resolution
RODS dont take alot of light to cause an action potential
Eyelid- sharks Nictitating membrane covers for protection
Discuss the adaptations of fish eyes- “Snell’s Window”
Depends on how eyes are positioned.
Directly 90 degrees above fish in the vision window to see 100%
Discuss the adaptations of fish eyes- ROYGBIV
RED 7.5m deep
ORANGE 10m deep
YELLOW 15m deep
GREEN 22.5m deep
BLUE 40 m deep
INDIGO 37.5m deep
VIOLET 22.5m deep
Discuss the adaptations of fish eyes- eye position
Telescope fish in front
Silver hatchet fishes above
Catfish long whiskers eyes directed downward
Barreleyes four eyes some directed downward
Stargazers above and eyes directed upward
Discuss the adaptations of fish eyes- field of view
Blindspot is the area of binocular or stereo vision directly in front of fish.
Monocular vision is viewed on either side of the fish
Discuss the adaptations of fish eyes- visual cells and pigments
DEEP OCEAN: RODS
visual pigments adapted to dim blue light, red sensitivity to bioluminescent emissions
COASTAL:
sensitivity to abundant light in blue green range
THROPICAL: CONES
strong blue light blue green and green many species with yellow corneas which facilitate attenuation of strong blue light
Discuss the adaptations of fish eyes- taptetum lucidum
Elasmobranchs have a reflective guanine crystals that reflect light and oriented allow the amount of reflection.
Allows them to hunt at night similar to cheetahs.
