Adaptations of Pygmy Gliders and Sloths

Chordates

• Chordates possess four key features:
  • Notochord: a stiff, flexible rod running along the body.
  • Dorsal, hollow nerve cord: situated above the digestive tract, developing into the brain.
  • Pharyngeal gill slits: located in the pharynx, potentially forming respiratory organs or grooves.
  • Post-anal tail: extends beyond the anus.

Notochord

• The notochord is a flexible, rod-like structure derived from mesoderm.
• It is the first part of the endoskeleton to appear in an embryo.
• Provides a place for muscle attachment.
• In vertebrates, the notochord is replaced by the vertebrae.
• Some notochord remnants might persist between vertebrae.

Tunicate

• Tunicates display a notochord, nerve cord, and gill slits in their larval stage.
• The adult form often loses these features.

Hagfishes

• Hagfishes are a type of chordate.

Amphibians, Reptiles (except Birds), Mammals and Birds

• Diagrams show the circulatory systems of these groups. The diagrams illustrate differences in the structure of their hearts and circulatory pathways.

Reptile Circulatory Systems (lizard, snake, crocodile, turtle)

• Diagrams illustrate the various heart structures in different reptiles.
• Key components, such as the right and left aorta, pulmonary arteries, atria, and ventricles, are labeled.

Distribution of species on Earth

• Land habitats have more species due to greater environmental variability than the ocean.
• Most ocean species are benthic (sea floor) because of the higher environmental variability compared to pelagic environments.

Adaptations of organisms to the marine environment

• Seawater presents several challenges for marine organisms.
  • High viscosity
  • Salinity variations
  • High transparency
  • Varying pressure with depth
• Marine organisms have adapted in various ways to address these conditions

Seawater's Viscosity

• Seawater viscosity depends on temperature; cold water has higher viscosity.
• Warm water has lower viscosity; organisms tend to sink.
• Adaptations include ornate appendages in warm waters and streamlined bodies in cold waters to aid swimming.

Variations in Salinity

• Coastal environments have more salinity variations compared to open ocean environments.
• Shallow-water organisms (euryhaline) can withstand a wide range of salinity.
• Deep-water organisms (stenohaline) can tolerate less variation.

Osmosis

• Marine fish drink large amounts of water and secrete concentrated urine to manage internal salt balance.
• Freshwater fish do not drink water and excrete dilute urine to avoid water accumulation.

Seawater's High Transparency

• Adaptations include transparency, camouflage, countershading, and migration.

Deep Scattering Layer (DSL)

• Organisms in the DSL (270-360 meters deep) migrate daily to darker, deeper waters during daytime.

Increase of pressure with depth

• Pressure increases rapidly with depth.
• Pressure impacts aquatic organisms, especially diving mammals and reptiles.
• Adaptations include collapsible lungs, flexible shells, and hemoglobin/myoglobin concentration to manage pressure.

Counter-current Heat Exchange

• Reptilian, in this case sea turtles, maintain body temperature efficiently by using this adaptation.
• Warm blood flowing away from the body core to appendages transfers heat to cooler returning blood, preventing heat loss.

Ocean Life Zones

• Describes various zones in the ocean:
  • Intertidal: close to shore
  • Neritic: shallow water
  • Oceanic: open ocean
  • Photic: sunlight-penetrated area
  • Aphotic: dark zone

Rocky Shores

• Rocky shores contain high biodiversity due to diverse places to live.
• Organisms must adapt to wave action and tidal changes.

Intertidal Zones (Spray/High/Mid/Low Tide Zones)

• Zones of the rocky shore experienced different water exposure.
• Organisms adapt to varying levels of exposure to air, water and wave action.

Physical Adaptations (Rocky Shores)

• Organisms develop adaptations to thrive in the rocky shores. Examples include:
  • Strong shells for defense against predators and desiccation
  • Antifreeze compounds in tissues
  • Flattened bodies/shells to reduce wave impact

Mussels

• Mussels anchor themselves with byssal threads to help withstand waves.
• Byssal threads are produced by glands to firmly attach to surfaces.

Hydrothermal Vent Communities

• Discovered in 1977, these communities thrive in areas of tectonic plate separation in the ocean floor.
• "Black smokers" release superheated water rich in minerals and sulfur.
• Chemosynthetic bacteria are primary producers in this community, using hydrogen sulfide released from the Earth's surface to acquire energy.

Ocean Floor

• Bacteria are free-living organisms.
• Some types of bacteria support mussels, clams, sea anemones, crabs, and fish.
• Giant tube worms lack guts, obtaining nourishment from bacteria within their bodies.
• The hydrothermal environment has unique ecosystems including giant tube worms and snails with iron-laden plates.

Hydrothermal Vent Snail

• A unique species found in hydrothermal vent communities.

Chemosynthetic Pathways in Riftia

• Chemosynthetic bacteria within the worm obtain energy from chemicals from hydrothermal vents.
• The bacteria process chemicals from hydrothermal vents that worms absorb for energy.

Freshwater Wetlands

• Most freshwater wetlands are dynamic, with water depth, velocity, turbidity, temperature, and oxygen concentration changing daily.

From Stream to River to Sea

• Various aquatic organisms exist in the ecosystem, from source region to ocean.
• Transition zones exist between streams, rivers, and ocean environments, featuring diverse organisms adapted to the changing conditions

Streams and Rivers

• Streams and rivers collect surface water, often flowing from mountainous source regions that are clear and cold due to the little sediment.
• Transitioning to wider, slower-moving rivers when elevation lowers, impacting organisms.
• Floodplains occur during periods of high precipitation.

Oligotrophic Lakes

• Nutrient-poor, glacier-formed lakes with clear water, supporting organisms like trout requiring well-oxygenated water.

Eutrophic Lakes

• Nutrient-rich lakes with high plant communities but murky water, supporting different organisms adapted to lower oxygen levels.

Estuaries

• Estuaries mix river freshwater with ocean saltwater.
• Key Features: brackish water, salinity gradient; transition zones between land and seas.
• Estuaries are important nurseries, habitats, and sources for food, and a place of recreation.

Important Functions of Estuaries (related to water)

• Water purification
• Flood control
• Buffer land from hurricanes and storm surge.

Tropical Rainforests

• Rainforests are close to the equator, experiencing constant warmth and high rainfall.
• Key characteristics include: high biodiversity, different plant and animal communities.
• The rainforest includes four layers: Emergent, canopy, understory, forest floor.
• Impacts of deforestation, loss of habitat and animal species is a concern.

More Facts about Rainforests

• Many animals found in rainforests are endemic and exist nowhere else.
• Indigenous people populate many rainforests, crucial to maintaining biodiversity.
• Rainforests cover a significant percentage of Earth's surface, but contain a large proportion of plant and animal species that exist nowhere else.
• Ongoing deforestation threatens the biodiversity of rainforests.

Tropical Rainforest-Key Information

• Rainforests hold more than half of the world’s plant and animal species.
• Rainforests act as carbon dioxide sinks, maintaining stable weather patterns.
• Rainforests are known as the "lungs of the world," contributing significantly to oxygen production.

Rainforests-Medicinal Value

• Rainforest organisms provide medicinal compounds for cancer treatment, malaria treatment, and other diseases.

Loss of Tropical Rainforest and its impact

• Tropical rainforest areas are being lost at a damaging pace in terms of their biodiversity.
• Tropical rainforest areas can take centuries to recover following deforestation.

Canopy Layer Animals

• The canopy layer in rainforests is the uppermost layer.
• Many animals live in this layer, including sloths.
• Sloths have unique adaptations like slow movements, fur-masking with algae, and strong claws.

Emergent Layer

• The emergent layer is the highest layer of the rainforest.
• Animals in this layer have adaptations to deal with exposure to weather elements, including flying, gliding, or crawling.

Emergent-Layer Birds

• Two major types of emergent layer birds include macaws and hummingbirds, primarily the bee hummingbird.

Macaws

• Macaws are large parrots with colorful plumage and strong beaks.
• They are social animals that nest in tree hollows.

Why clay?

• Clay is used by animals to neutralize alkaloids found in their food.

Gliders and Lizards

• Gliders
• Draco Lizards