L7 Sensing Fish

Question 1

What can colour be used for

Answer 1

Concealment; countershading, resemblance, disruptive, disguise, mimicry
Advertisement: predators/prey, mating,

Question 2

Example of Mimicry

Answer 2

Cleaner wrasse removes ectoparasites and sabertoothed blenny mimics it, and bites off piece of flesh

Question 3

Colouration Cells

Answer 3

Chromatophores
- have biochromes (pigments) within the cells, these can concentrate (become less visible) or disperse (become more visible) from NS and Endocrine control
- Colour change : number and location of chromatophore
Schematochromes
- mirror like to reflect light

Question 4

Bioluminescence

Answer 4

Photophores
- bacteria
- reaction : luciferin + ATP + O2 -> Light using luciferase
- often have window for light to escape and reflector behind

Question 5

Sound Production

Answer 5

from : teeth/skeletal, gas bladder
for: mating, territorial, communication
Ex: Freshwater Drum males: vibrate muscles - tendons across gas bladder = rumbling

Question 6

Electricity

Answer 6

Usually turbid waters, nocturnal, slow moving spp
- reduced eyes, thickened skin,
- enlarged cerebellum
Current generated by electrocytes: muscle cells in stacks (eletrical differential accumulates)