Position maintenance

These flashcards cover key concepts related to functional and behavioral adaptations of marine organisms to their environments, focusing on position maintenance, adhesion mechanisms, and the effects of environmental factors.

Why is it important for marine organisms to stay put in their environment?

To maximize optimal conditions for growth and reproduction, avoid predation, and prevent unfavorable physical or chemical conditions.

What adaptation do macrolagae have to reduce shear stress in marine environments?

Macrolagae have a flexible stipe and frond that exploit the boundary layer, creating undulations to reduce shear stress.

How does wave force affect the frond size of algae?

Wave force directly affects frond size, with fronds increasing in size in sheltered areas compared to exposed areas.

What are the three types of adhesion to rocky substrates mentioned?

Permanent adhesion (e.g., barnacles), transitory adhesion (e.g., gastropods), and temporary adhesion (e.g., echinoderm podia).

What are byssus threads, and where are they found?

Byssus threads are proteinaceous structures used for adhesion, found in Mytilidae (mussels).

What is the drag coefficient for Strongylocentrotus purpuratus?

The drag coefficient for Strongylocentrotus purpuratus is 0.67.

How do urchins manage drag forces during high flow velocities?

Urchins depress the angle of their spines to reduce drag forces, although this increases lift forces.

What behaviour do foam mats exhibit during the daytime for position maintenance?

Foam forms bubble mats for buoyancy, keeping organisms near-shore by surface currents.

How do bivalve larvae maintain their position in estuaries?

They utilize selective tidal stream transport, where larvae drift during flooding tides and sink during ebbing tides.

What challenge do crustaceans face in relation to artificial light at night?

Artificial light at night (ALAN) alters their behavior, potentially disrupting position maintenance and navigation.

What are the two primary hydrodynamic forces marine organisms must resist to stay in place?

Drag (parallel to flow) and Lift (perpendicular to flow).

How do gastropods achieve transitory adhesion to the substrate?

They use a muscular foot combined with mucus, allowing for movement while maintaining a secure contact with the surface.

What substance do barnacles use for permanent adhesion?

Barnacles secrete a proteinaceous glue or calcareous cement that hardens upon contact with seawater to fix them to a substrate.

What is the boundary layer in the context of marine fluid dynamics?

The boundary layer is a thin region of water near the substrate where flow velocity is significantly reduced compared to the main flow due to friction.

How do some marine larvae use vertical migration to prevent being washed out to sea?

By moving into incoming flood tides to travel up-estuary and sinking to the slower bottom layers during ebbing tides to maintain their position.

How do soft-sediment organisms typically maintain their position?

Through burrowing behaviors and the construction of stable tubes or galleries within the sand or mud.