Fishes Behavior

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• Fishes - Behavior
• Migration
• Anadromous
• Spawn in fresh water
• Spend most of life in ocean
• Ex Salmon (seven species) in Pacific Ocean
• Spawn in shallow areas of rivers/streams
• Semelparous (adults die after spawning)
• Young migrate downstream to ocean after 0-5 years
• Spend 3-7 years in ocean before returning to home
  stream
• Homing behavior enabled by olfactory imprinting
• Habitat degradation and loss has greatly reduced
  salmon populations

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Fig. 8.22
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• Fishes - Behavior
• Migration
• Catadromous
• Spawn in ocean
• Spend most of life in fresh water
• Ex Eels (16 species) in Atlantic Ocean
• Spawn in Sargasso Sea (400-700 m or deeper)
• Semelparous
• Eggs hatch into leptocephalus larvae
• Larvae spend a year or more as plankton then
  undergo metamorphosis into juveniles
• Adults spend 10-15 years in fresh water before
  migrating to Sargasso Sea to spawn

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Fig. 8.24
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Fig. 9.1
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• Marine Reptiles
• Secondarily marine
• Ectotherms and poikilotherms
• Sea Turtles
• Unable to retract head or legs into shell
• Legs modified as flippers for swimming
• Eight species Mainly warm water
• Some migrate or may appear in temperate waters
• Diet varies among species
• Benthic invertebrates Kemps ridley,
  loggerhead, flatback (also jellyfish)
• Sponges Hawksbill
• Jellyfish Leatherback
• Sea grasses Green, black (also jellyfish)
• Diverse Olive ridley (crustaceans, jellyfish,
  algae)

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• Marine Reptiles
• Sea Turtles
• Mate offshore
• Lay eggs on land at night
• Dig hole in sand and lay up to 160 eggs
• Incubation period two months
• Gender of hatchlings determined by incubation
  temperature
• Warm ? Females
• Cool ? Males
• Females return to same beach each year
• DNA evidence that site fidelity spans generations
• Require 10 years to reach sexual maturity
• All species endangered or threatened
• Overhunting shell, meat
• Development Loss of beaches
• Accidents Collisions with boats, entanglement
  in nets, etc.
• Use of TEDs

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• Marine Reptiles
• Sea Snakes
• 55 species Mainly tropical (Indian, Pacific)
• Coral reefs, open ocean
• Bodies flattened laterally (3-4 feet long at
  maturity)
• Paddle-shaped tail
• Immense lungs (extend into tail)
• Can dive to 150 m (typically 5 m)
• Can hold breath for 2 hours!
• Ovoviviparous
• Few species lay eggs on shore
• Venomous
• Closely related to cobras
• Venom typically used to kill small prey (fishes,
  squids)
• May hunt in schools
• Some actively trap prey others lie in wait
• Not aggressive humans rarely bitten
• Few natural predators (seabirds, sharks,
  saltwater crocodiles) threatened by humans

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• Marine Reptiles
• Marine Iguana
• One species Galápagos Islands
• Males colored more brightly than females
• Different populations (different coloration) on
  various islands
• Feed on algae
• Can dive to 15 m
• Can hold breath for 30-60 minutes
• Eliminate salt through salt glands near nostrils
• Good swimmers
• Long, laterally flattened tail
• Territorial
• Males fight to establish territories
• Males maintain harems
• Females dig nests in sand for eggs

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• Marine Reptiles
• Saltwater Crocodile
• One species E Indian Ocean, W Pacific,
  Australia
• Mostly inhabit mangrove forests
• Largest crocodile species - Males larger than
  females
• May reach 23 feet and 1000 kg
• Diverse diet
• Crustaceans, snakes, birds, mammals
• Aggressive and potentially dangerous to people
• Slow to reach sexual maturity
• Males mature at 15-16 years females at 10-12
  years

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• Seabirds
• About 300 species
• Spend a significant part of life at sea
• Feed on marine organisms
• Webbed feet for swimming
• Endotherms and homeotherms
• Allows seabirds to live in a wide variety of
  conditions
• Need considerable food to maintain body
  temperature in cold regions
• Feathers help conserve body heat
• Gland above base of tail produces oil that birds
  add to feathers with preening
• Trapped air provides insulation and buoyancy
• Hollow bones
• Facilitate flight
• Nest on land
• Often colonial
• Frequently mate for life

Gannet
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• Seabirds
• Diversity
• Body Form
• Flightless penguins with rudimentary wings
• Albatrosses with 12 foot wingspans
• Except for gulls, most seabirds are adapted to
  life in/on the ocean, cant walk well on land and
  are vulnerable to mobile land predators
• Lifestyle
• Flightless cormorants
• Frigatebirds that depend completely on extensive
  flight
• Diet
• Small zooplankton Prions
• Fishes Penguins
• Squids Petrels
• Benthic invertebrates Razorbill
• Other birds Petrels
• Resource partitioning is common (minimizes
  competition)
• Geographic Range
• Restricted to limited region Storm petrels

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• Seabirds
• Beak Shape
• Short, heavy, hooked beak
• Holding and tearing prey too large to be eaten
  whole
• Best for shallow feeding and eating other birds
• Ex - Petrels
• Short, heavy, streamlined beak
• Grabbing prey, usually to ingest whole
• Streamlined shape doesnt interfere with swimming
• Ex Penguins, razorbills
• Straight, narrow beak
• Grabbing prey to ingest whole
• Used by plunge divers doesnt interfere with
  dive
• Ex Boobies, terns
• Elongated lower beak
• Used for feeding while flying
• Lower beak used to catch prey
• Ex - Skimmers

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Fig. 9.7
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• Seabirds
• Beak Shape
• Short, heavy, hooked beak
• Holding and tearing prey too large to be eaten
  whole
• Best for shallow feeding and eating other birds
• Ex - Petrels
• Short, heavy, streamlined beak
• Grabbing prey, usually to ingest whole
• Streamlined shape doesnt interfere with swimming
• Ex Penguins, razorbills
• Straight, narrow beak
• Grabbing prey to ingest whole
• Used by plunge divers doesnt interfere with
  dive
• Ex Boobies, terns
• Elongated lower beak
• Used for feeding while flying
• Lower beak used to catch prey
• Ex - Skimmers

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Fig. 9.7
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• Seabirds
• Beak Shape
• Short, heavy, hooked beak
• Holding and tearing prey too large to be eaten
  whole
• Best for shallow feeding and eating other birds
• Ex - Petrels
• Short, heavy, streamlined beak
• Grabbing prey, usually to ingest whole
• Streamlined shape doesnt interfere with swimming
• Ex Penguins, razorbills
• Straight, narrow beak
• Grabbing prey to ingest whole
• Used by plunge divers doesnt interfere with
  dive
• Ex Boobies, terns
• Elongated lower beak
• Used for feeding while flying
• Lower beak used to catch prey
• Ex - Skimmers

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Fig. 9.7
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• Seabirds
• Beak Shape
• Short, heavy, hooked beak
• Holding and tearing prey too large to be eaten
  whole
• Best for shallow feeding and eating other birds
• Ex - Petrels
• Short, heavy, streamlined beak
• Grabbing prey, usually to ingest whole
• Streamlined shape doesnt interfere with swimming
• Ex Penguins, razorbills
• Straight, narrow beak
• Grabbing prey to ingest whole
• Used by plunge divers doesnt interfere with
  dive
• Ex Boobies, terns
• Elongated lower beak
• Used for feeding while flying
• Lower beak used to catch prey
• Ex - Skimmers

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Fig. 9.7
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• Seabirds
• Prey Capture
• Aerial pursuit
• Chase other birds harass them into dropping prey
• Ex Jaegers, frigatebirds
• Surface plunging
• Dive to capture near-surface prey
• Ex Pelicans, boobies
• Dipping
• Snatch near-surface prey
• Ex Gulls
• Pattering
• Walk along surface, grabbing near-surface prey
• Ex Storm petrels
• Pursuit plunging
• Shallow dive with some pursuit of prey underwater
• Ex Shearwaters
• Pursuit diving with wings

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Fig. 9.8
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• Seabirds
• Prey Capture
• Aerial pursuit
• Chase other birds harass them into dropping prey
• Ex Jaegers, frigatebirds
• Surface plunging
• Dive to capture near-surface prey
• Ex Pelicans, boobies
• Dipping
• Snatch near-surface prey
• Ex Gulls
• Pattering
• Walk along surface, grabbing near-surface prey
• Ex Storm petrels
• Pursuit plunging
• Shallow dive with some pursuit of prey underwater
• Ex Shearwaters
• Pursuit diving with wings

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Fig. 9.8
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• Seabirds
• Prey Capture
• Aerial pursuit
• Chase other birds harass them into dropping prey
• Ex Jaegers, frigatebirds
• Surface plunging
• Dive to capture near-surface prey
• Ex Pelicans, boobies
• Dipping
• Snatch near-surface prey
• Ex Gulls
• Pattering
• Walk along surface, grabbing near-surface prey
• Ex Storm petrels
• Pursuit plunging
• Shallow dive with some pursuit of prey underwater
• Ex Shearwaters
• Pursuit diving with wings

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Fig. 9.8
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• Seabirds
• Prey Capture
• Aerial pursuit
• Chase other birds harass them into dropping prey
• Ex Jaegers, frigatebirds
• Surface plunging
• Dive to capture near-surface prey
• Ex Pelicans, boobies
• Dipping
• Snatch near-surface prey
• Ex Gulls
• Pattering
• Walk along surface, grabbing near-surface prey
• Ex Storm petrels
• Pursuit plunging
• Shallow dive with some pursuit of prey underwater
• Ex Shearwaters
• Pursuit diving with wings

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Fig. 9.8
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• Seabirds
• Prey Capture
• Aerial pursuit
• Chase other birds harass them into dropping prey
• Ex Jaegers, frigatebirds
• Surface plunging
• Dive to capture near-surface prey
• Ex Pelicans, boobies
• Dipping
• Snatch near-surface prey
• Ex Gulls
• Pattering
• Walk along surface, grabbing near-surface prey
• Ex Storm petrels
• Pursuit plunging
• Shallow dive with some pursuit of prey underwater
• Ex Shearwaters
• Pursuit diving with wings

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Fig. 9.8
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• Seabirds
• Prey Capture
• Aerial pursuit
• Chase other birds harass them into dropping prey
• Ex Jaegers, frigatebirds
• Surface plunging
• Dive to capture near-surface prey
• Ex Pelicans, boobies
• Dipping
• Snatch near-surface prey
• Ex Gulls
• Pattering
• Walk along surface, grabbing near-surface prey
• Ex Storm petrels
• Pursuit plunging
• Shallow dive with some pursuit of prey underwater
• Ex Shearwaters
• Pursuit diving with wings

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Fig. 9.8
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• Seabirds
• Prey Capture
• Aerial pursuit
• Chase other birds harass them into dropping prey
• Ex Jaegers, frigatebirds
• Surface plunging
• Dive to capture near-surface prey
• Ex Pelicans, boobies
• Dipping
• Snatch near-surface prey
• Ex Gulls
• Pattering
• Walk along surface, grabbing near-surface prey
• Ex Storm petrels
• Pursuit plunging
• Shallow dive with some pursuit of prey underwater
• Ex Shearwaters
• Pursuit diving with wings

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Fig. 9.8