Lecture 8 - Sensory Adaptations and Bioluminescence

Question 1

What is chemosensitivity?

Answer 1

adaptation for smell
Benthic and near-benthic spps rapidly arrive at bait
Pelagic - absence of turbulence = scent trail

Question 2

Ways of detecting fluid movement past an organism

Answer 2

Mechanoreception

• lateral line organs of fishes
• sensory hairs and long antennae of crustaceans

Question 3

Which fishes have the most developed mechanoreception?

Answer 3

Well developed in midwater and near bottom fishes

Bathypelagic and deeper fishes have prominent lateral line organsd

Question 4

Which light is transmitted best in clear water?

Answer 4

Blue light (~470 nm)

Question 5

Why is bioluminescence close to the wavelength of blue light?

Answer 5

(~470 nm)

• transmit further
• matches downwelling light for counterillumination

Question 6

Light penetration in open ocean

Answer 6

blue light penetrates furthest

Question 7

Light penetration in coastal waters

Answer 7

green/yellow light penetrates furthest

Question 8

Why is red coloration just as good as black in the deep ocean?

Answer 8

Since blue light is predominant, red objects show up as black because there is no red light to be reflected by the red pigments in the red spps

Question 9

What do fish use for their coloration?

Answer 9

Melanins, which tend to be brown or black

Question 10

What do crustaceans use for their coloration?

Answer 10

Carotenoids, which by themselves, without proteins, are red and orange.

Question 11

Eyes of deep water fish are more sensitive to ______ than freshwater fish

Answer 11

blue light

fresh water fisher see longer wavelengths

Question 12

Why deep-sea animals have eyes with maximum absorbance around blue light?

Answer 12

So they can see bioluminescence and downwelling celestial light
(more adapted to see bioluminescence)

Question 13

Which fish use red photophores to detect red light?

Answer 13

Malacosteid fishes

Question 14

When do animals bioluminescence?

Answer 14

When disturbed

Question 15

Visual adaptations

Answer 15

1. Match color sensitivity to color of light received
2. Use pigmented lenses
3. Increase sensitivity to light (detection over sensitivity)
4. Reduced landscape viewing, increased ability to detect spots

Question 16

How do fishes match color sensitivity to color of light received?

Answer 16

blue absorption maxima

Question 17

How do fishes use pigmented lenses?

Answer 17

use yellow lenses to discriminate between downwelling light and bioluminescence

Question 18

How do fishes increase sensitivity to light?

Answer 18

Rod only retinas
Banked rods (multiple layers) in retinas
Longer rods
Reflecting tapetum of matched color behind rods
Rods linked via neurons to function as a single receptor

Question 19

How do fishes reduce landscape viewing and increase their ability to detect spots?

Answer 19

Densely packed rods in foveae of eye (in retina)
Reduced eye size
Often telescopic eyes

Question 20

How do crustaceans improve their eyesight?

Answer 20

As they go deeper, individual rods become packed and lose their screening pigment

Question 21

What is Bioluminescence?

Answer 21

Form of chemiluminescence where a substrate and enzyme produce light

Question 22

Proposed explanations for bioluminescence

Answer 22

Vision
Lure
Startle/decoy
Counterillumination
Burglar alarm
Communication
Warning pattern
Bacteria

Question 23

4 luciferins of most bioluminescence

Answer 23

Luciferin
Aldehyde
Luciferase
Photoprotein

Question 24

Who uses Bacteria for their bioluminescence?

Answer 24

Fish (including anglerfishes), pyrosomes, squid

Question 25

Who uses Coelenterazine for their bioluminescence?

Answer 25

Jellyfish (cnidarians) , Lophogastrids, shrimp, copepods, ect.

Question 26

Who uses vargulin for their bioluminescence?

Answer 26

Midshipman fish

Question 27

What kind of bioluminescence is used by vampire squids and where does this occur?

Answer 27

Use coelenterazine
-tips of arms
-sticky secretion from near tips of arms
(diversions, lures)

Question 28

How is bioluminescence used for luring?

Answer 28

Biolum is used to bring prey close (anglerfishes)

Question 29

How is biolum used for startle/decoy?

Answer 29

Predator triggers a biolum cloud which startles and distracts predator while prey escapes

Question 30

How is biolum used for counterillumination?

Answer 30

Biolum directed downward obliterates shadows from light above the fish

Question 31

How is biolum used for burgalr alarm?

Answer 31

Prey creates biolum to attract a predator on its predator

Question 32

How is biolum used for communication?

Answer 32

species and sex specific patterns of photophores and flash timing (like fireflies)

Question 33

How is biolum used for warning?

Answer 33

Biolum indicates to predators that they are not good to eat (possible in jellies, sea cucumbers?)

Question 34

How doe bacteria use biolum?

Answer 34

Biolum to be eaten and flourish in richer gut environment

Question 35

How many times has biolum independently evolved?

Answer 35

30?

Question 36

What features would indicate biolum in the area?

Answer 36

Eyes where there is no light

Red coloration to hide in blue light

Question 37

What is the Red Tide?

Answer 37

Burglar alarm set off by stimulated Dinos

Question 38

How can biolum help to detect subs?

Answer 38

Subs disturb waters wit biolum animals/bacteria, which biolum to indicate presence of subs