(4) Adaptations of Marine Organisms to Environmental Changes

Organismal response

Organisms react to environmental variations throughout life.

Adaptive responses

Responses include behavioral, physiological, and biochemical changes.

Acclimation

Adjustment of physiology to new environmental conditions.

Regulators

Maintain constant internal parameters despite external changes.

Conformers

Allow internal parameters to fluctuate with external conditions.

Homeotherms

Organisms that regulate body temperature above ambient.

Poikilotherms

Organisms conform to external temperatures.

Heat loss

Most heat lost through skin conduction.

Convective heat loss

Heat loss via warm blood contact with body surface.

Insulation

Methods like fur or blubber reduce heat loss.

Vasoconstriction

Narrowing of blood vessels to conserve heat.

Countercurrent heat exchange

Heat transfer between arteries and veins.

Metabolic rate

In poikilotherms, increases with temperature rise.

Heat shock proteins (HSP)

Proteins protect structure under high temperature stress.

Ubiquitin

Protein involved in degrading damaged proteins.

Freeze tolerance

Ability to survive freezing conditions without damage.

Antifreeze compounds

Substances preventing tissue freezing in fish.

Osmosis

Movement of water towards higher solute concentration.

Osmoregulators

Organisms that maintain internal salt balance.

Active pumping

Mechanism to regulate internal salt concentrations.

Anaerobes

Organisms that do not require oxygen for metabolism.

Aerobes

Organisms that depend on oxygen for energy production.

Oxygen uptake

Process of absorbing oxygen through diffusion or gills.

Oxygen-binding pigments

Molecules that increase oxygen transport capacity.

Photosynthesis

Process converting sunlight into energy by organisms.