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Fishes as prey: avoiding
predation
Avoidance of predatorsAdaptations of prey
Predator – Prey arms race
• Co-evolution of predatory and escape mechanisms– Morphological adaptations– Behavioral adaptations– Ecological adaptations
“there is no perfect predatory nor perfect escape tactic”
Predation Cycle
• Search• Pursuit• Attack• Capture• Handling of Prey
Detection avoidance• Camouflage (avoidance of visual
predators)
Appearance of something unrecognizableDisappearance - become invisible
– Protective resemblance• Resemble background• Resemble inedible objects• Resemble predators
Detection avoidance• Camouflage (avoidance of visual
predators)
Appearance of something unrecognizableDisappearance - become invisible
– Protective resemblance• Resemble background• Resemble inedible objects• Resemble predators
– Disruptive coloration• Daytime• Nightime
Detection avoidance• Pelagic camouflage (avoidance of visual
predators)
– Countershading
Looking downwardsLooking upwards
Looking downwards
Detection avoidance• Pelagic camouflage (avoidance of visual
predators)
– Countershading
– Mirror sides
Mirror Sides
Detection avoidance• Pelagic camouflage (avoidance of visual
predators)
– Countershading
– Mirror sides
– Transparency
Detection avoidance• Pelagic camouflage (avoidance of visual
predators)
– Countershading
– Mirror sides
– Transparency
– Counterillumination (Bioluminescence)
Hatchetfish
Myctophid lanternfish
Detection avoidance• Pelagic camouflage (avoidance of visual
predators)
– Countershading
– Mirror sides
– Transparency
– Counterillumination (Bioluminescence)
• Olfaction avoidance (Avoidance of olfactory predators) – Mucous cocoon
Pursuit evasion• Morphological adaptations
– Stout and/or sharp spines– Poisonous spines– Toxic fishes
Usually with Aposematic Coloration (but not always)
Pursuit evasion• Morphological adaptations
– Stout and sharp spines– Poisonous spines– Toxic fishes
Usually with Aposemotic Coloration
• Behavioral adaptations– Use of bottom shelter– Use of holes and caves– Flying
Capture and Handling discouragement
• Body armours• Long dorsal and anal spines• Extra deep bodies• Inflation• Erection of sharp spines….
