Feeding: Fishes as predators Feeding & Predation cycles Adaptations of predators

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 (Feeding Cycle) Handling of Prey (Feeding Cycle)

Feeding Cycle Biting Sucking Chewing Swallowing

Search Active Search (Use of locomotion while employing senses to detect prey) -Vision (Water column predators) Herring & Anchovies Tunas & Billfishes Nocturnal Plankton feeders

Search Active Search (Use of locomotion while employing senses to detect prey) -Vision (Water column predators) Herring & Anchovies Tunas & Billfishes Nocturnal Plankton feeders –Olfaction Elasmobranchs Moray eels

Search Active Search (Use of locomotion while employing senses to detect prey) -Vision (Water column predators) Herring & Anchovies Tunas & Billfishes Nocturnal Plankton feeders –Olfaction Elasmobranchs Moray eels –Hearing Elasmobranchs (low frecuency sounds Hz)

Search Active Search (Use of locomotion while employing senses to detect prey) -Taste / Touch (benthic feeders) Barbels (Catfishes, Goatfish, Croakers, etc…) Modified fin rays (Sea robins, etc…)

Search Active Search (Use of locomotion while employing senses to detect prey) -Taste / Touch (benthic feeders) Barbels (Catfishes, Goatfish, Croakers, etc…) Modified fin rays (Sea robins, etc…) –Electroreception Passive (Elasmobranchs) Active (Elephantfish, Gimnotids, etc…)

Search Active Search (Use of locomotion while employing senses to detect prey) -Taste / Touch (benthic feeders) Barbels (Catfishes, Goatfish, Croakers, etc…) Modified fin rays (Sea robins, etc…) –Electroreception Passive (Elasmobranchs) Active (Elephantfish, Gimnotids, etc…) Speculation Search (‘try and see’ chicken tactic…) usually occurs with attendant species

Search Passive Search – Camouflage Predators (No use of locomotion) -Benthic Stalkers (Flounders, Scorpionfish, etc…) Vision Electrorecepcion

Search Passive Search – Camouflage Predators (No use of locomotion) -Benthic Stalkers (Flounders, Scorpionfish, etc…) Vision Electrorecepcion –Open Water Stalkers (gars, pike, trumpetfish) Vision

Pursuit High Speed chases -Specific to capture fast prey Open Water – Speed –Lamnid sharks, Tuna, Marlin… Benthic – Fast Braking and turning –Salmon, Striped Bass, Groupers…

Pursuit High Speed Chases -Specific to capture fast prey Open Water – Speed –Lamnid sharks, Tuna, Marlin… Benthic – Fast Braking and turning –Salmon, Striped Bass, Groupers… Fast Start Interception –Convergent evolution of body shape –Pike, Barracuda, Gars, Needlefish…

Pursuit High Speed chases -Specific to capture fast prey Open Water – Speed –Lamnid sharks, Tuna, Marlin… Benthic – Fast Braking and turning –Salmon, Striped Bass, Groupers… Fast Start Performance –Convergent evolution of body shape –Pike, Barracuda, Gars, Needlefish… Luring –Lophiiformes (fin rays), stargazers (buccal lures), Haplochromis livingstoni (death feigning)...

Attack, Capture & Handling Directly related to jaw development Feeding Cycle (Biting, Sucking, Chewing, Swallowing) Mouth Positioning –Superior –Terminal –Inferior

Attack, Capture & Handling Directly related to jaw development Feeding Cycle (Biting, Sucking, Chewing, Swallowing) Mouth Positioning –Superior –Terminal –Inferior Suction Feeding (Jaw Protrusion) –Premaxillae, Maxillae & Lower Mandible –Preparation, Expansion, Compression, Recovery Pharyngeal Jaw –Handling / Chewing & Swallowing

Extreme Jaw Protrusion 65% Head Length

Attack, Capture & Handling Overtake or Interception of prey Suction of Prey –Fastest movements if mobile prey (example: Frogfish expand mouth 14-fold in 6 milliseconds) –Slower movement if prey with limited movement

Attack, Capture & Handling Overtake or Interception of prey Suction of Prey –Fastest movements if mobile prey (example: Frogfish expand mouth 14-fold in 6 milliseconds) –Slower movement if prey with limited movement Filtering of prey –Swim with open mouths, filter planktonic prey

Filtering of Prey

Cetorhinidae Basking shark Cetorhinus maximus Filtering of Prey

Attack, Capture & Handling Overtake or Interception of prey Suction of Prey –Fastest movements if mobile prey (example: Frogfish expand mouth 14-fold in 6 milliseconds) –Slower movement if prey with limited movement Filtering of prey –Swim with open mouths, filter planktonic prey Prey Immobilization –Marlin, swordfish, sawfish (upper jaw extension) –Thresher Shark (tail) –Torpedo Rays (Electrical discharge) –Hammerhead Shark (head)