The Seagrasses The Seagrasses Dr Kim Peyton Dr Kim Peyton Dr. Kim Peyton (w/ some modifications by Dr. Bruland) University of Hawai‘i Mānoa D t t fB t Dr. Kim Peyton (w/ some modifications by Dr. Bruland) University of Hawai‘i Mānoa D t t fB t Department of Botany Department of Botany 1
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The SeagrassesThe Seagrassesgg
Dr Kim PeytonDr Kim PeytonDr. Kim Peyton (w/ some modifications by Dr. Bruland)
University of Hawai‘i MānoaD t t f B t
Dr. Kim Peyton (w/ some modifications by Dr. Bruland)
University of Hawai‘i MānoaD t t f B tDepartment of BotanyDepartment of Botany
1
Outline• Anatomy• Characteristics• Taxonomy systematics & evolutionTaxonomy, systematics, & evolution• Distribution & diversity• Habitats• Reproduction • Food sources• Annual production• Annual production• Stressors• Hawaiian seagrassesg• Seagrass research in Hawai‘i
AnchoringAnchoring Propagation Nutrient absorption Gas e changeGas exchange
• Roots -Nutrient uptake Anchoring Gas exchange
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Vegetative Morphology
• Leaves: strap-like to poval
• Leaf bundlesLeaf bundles • Short shoots
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Conveyor belt growthConveyor-belt growth
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Characteristics of Seagrasses:Functional Group
Characteristics of Seagrasses:Functional GroupFunctional Group
Arbor (1920) & den Hartog (1970)Functional Group
Arbor (1920) & den Hartog (1970)
1. Adapted ecologically to varying salinities = osmoregulation
1. Adapted ecologically to varying salinities = osmoregulation
2. Able to grow while completely submerged
2. Able to grow while completely submerged
3. Resistant to waves & tidal currents4. Adapted to pollinate underwater = 3. Resistant to waves & tidal currents4. Adapted to pollinate underwater = p p
hydrophilly5.
p phydrophilly
5.
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How extraordinary are seagrasses?How common is hydrophily?How common is hydrophily?
• 130 species of 300,000 species• Hydrophiles = 0.04%• 60 species are marine = seagrasses• Seagrasses = 0.02%• Reflects difficult evolutionary transitions
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From where did seagrassesFrom where did seagrassesoriginate?
Origins of this relationship found in late Cretaceous withOrigins of this relationship found in late Cretaceous with first appearance of seagrasses & mangroves.