Special Habitats

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Special Habitats

• Extreme conditions
• Require unique adaptations
• Deep sea
• Polar
• Deserts and Hot Environments
• Caves

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Deep Sea Issues

• What issues might require adaptations in deep sea
  fishes?
• a)
• b)
• c)
• d)
• e)

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Temperature

• Stable 2-4C below 1000 meters
• Movement to
• surface (18-25C)
• vents (8-16C)
• Physiology adapted to
• cold
• OR
• wide range of temps

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Ecological Stratification

• temperature governs mesopelagic community
  structure
• 10-20C myctophiforms, some stomiiforms
• 5-10C other stomiiforms
• Communities follow tropical submergence

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Pressure

• 10 m 1 atm
• 4000m 6000 lbs/in2
• Physiology adapted to
• high pressure
• OR
• range of pressure
• Swim bladder
• mesopelagics vs bathypelagics?

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Space

• Largest habitat is ocean below 1000m
• Huge volume but few individuals
• Potential difficulties
• finding food
• finding a mate

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Productivity

• Trophic input?
• Limited prey
• Feeding adaptations
• large mouths
• large teeth
• large guts

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Light

• Bioluminescence
• Prey attraction
• Mate attraction
• Communication
• Camouflage

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Mesopelagic Adaptations

• Active, muscular fishes
• Well-developed skeleton and scales
• Large eyes
• some directed upwards
• Countershading or dark bodies

Hygophum benoiti
Argyropelecus sp.
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Bathypelagic Adaptations

• Sedentary
• weak musculature
• jelly-like blobs
• Poorly ossified skeletons, no scales
• Poorly developed or non-functional eyes
• Uniformly dark bodies
• Lateralis and chemosensory systems often highly
  developed

Melanocetus johnsoni
Psychrolutes sp.
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Benthal Adaptations

• Benthic rover-predators, rattails, flatfishes
• Feed on comparatively rich benthic fauna
• Increased sensory areas
• lateralis system
• chemosensory
• touch