Chapter 4: Adaptations General

Adaptations

biological characteristics, evolved over time, that allow organisms to colonize and expand their population in a given environment

Thermal Optimum

the temperature that supports maximum growth

Euthermal Organisms

tolerate wide variations in temperature

Stenothermal Organisms

cannot tolerate variation in temperature

Ectotherms

‘cold-blooded’ species that depend on their surrounding environment for heat

bleaching

loss of colour in symbiont dinoflagellates and the host corals

acclimatization

the process by which an organism adjusts to changes in its environment in order to survive

Hematocrit

percentage of blood volume occupied by the cellular component

Hemoglobin

protein responsible for oxygen transport

Cutaneous Vasculature

the blood vessels that supply oxygen to the skin

Anti-freeze glycoproteins

specialized proteins in blood that reduce freezing temperatures

Psychrotrophic Bacteria

‘cold loving’ bacterial taxa, usually restricted to permanently cold habitats

Obligate Psychrophiles

Bacterial taxa that require cold conditions and die at temperatures above 4 degrees celcius

Heat-shock Proteins

Specialised proteins that protect enzymes by forming enzyme complexes that protect the enzyme

Chemocline

a chemical gradient

Denaturing

alteration or breakdown, as in protein denaturing, which alters metabolic pathways

Hydrothermal Vents

the cracks in the Earth’s crust near spreading and subduction zones along the edges of ocean plates where superheated seawater rich in dissolved minerals and chemicals spews out

Trophosome

a specialized organ in hydrothermal vent tube worms that houses a rich bacterial flora of chemoautotrophic symbionts

Chlorocruorin

a green, iron-containing respiratory pigemnt found dissolved in the blood plasma of certain marine polychaete worms that functions to transport oxygen

Hemocyanin

a copper-containing protein in the blood of many invertebrates (like mollusks) that transports oxygen to give the blood a blue colour when exposed

Hemovanadin

a pale green, vanadium-containing protein found in blood cells of sea squirts acting as metal-binding agent rather than to carry oxygen

Hemerythrin

a non-heme, iron-containing protein that functions as an oxygen carrier in some marine invertebrates

Hemoglobin

a red, iron-containing protein in red-blood cells that transports oxygen in almost all vertebrates

Normoxic/oxic

normal levels of oxygen necessary to support most organisms

Hypoxic

low levels of oxygen, often defined as concentrations less than 2.0 mL/L

Anoxic

no oxygen conditions

Stenohaline

species highly sensitive to salinity changes in organisms

Euryhaline

species that can tolerate a wide range of salinities

Catabromous Species

spawn in the sea but develop and typically mature in freshwater

→eels

Anadromous Species

live in marine waters and return to rivers to spawn

→salmon

Ampjidromous Species

move between fresh water and seawater but not for reproduction

→Mullet

Homeosmotic Organisms/ Osmotic Regulators

maintain a constant internal salt concentration

Osmotic Conformers

species in which internal slat concentrations effectively track their environment

Stenohaline

species highly sensitive to salinity changes

Euryhaline

species that can tolerate a wide range of salinities

Hypertonic

maintaining higher concentrations of solute compared to surrounding seawater

Hypotonic

maintaining lower concentrations of solutes compared to surrounding seawater

Osmolytes

small organic Molecules produces by cells

Hypertonic Urine

an adaptation to salinity where urine is very concentrated with salt to conserve water

Barotolerant/ Piezotolerant

tolerate a wide range of pressures

Eurobathic

species span a wide depth of ranges

Pressure’s Effect on Enzymes

changes shape, and in turn function, of enzyme; organisms must adapt

Adaptations to light

• photosynthesis

• predator/prey

• communication/mating

• Orientation

Counter-shading

body coloring that reduces visability of prey to their predators against surface lighting

Methods of marine animals’ luminescence

• extracellular secretions of luminescent material produced by glands

• intracellular processes

• symbiotic bacteria

macronutrients

nutrients required in relativity high concentrations by photosynthetic organisms, specifically nitrate, phosphate, and silicon

micronutrients

nutrients required in low concentrations by photosynthetic organisms, such as iron, magnesium, and zinc

Ampoules of Lorenzini

electroreceptors; that form a network of mucus-filled pores in the skin of sharks, and rays

melon

structure in the head of dolphins that acts as a lens for locating prey, focusing acoustic waves in a narrow beam projected forward

biosonar

an auditory imaging system used by various species to navigate and to estimate the location of prey in environments where visual cues are ineffective →echolocation

cavitation

the formation of gas bubbles in liquids that move when pressure drops below that of water vapor while the surrounding temperature remains constant

lateral line

a visible line along the side of a fish consisting of a series of sense organs that detect pressure and vibration

vocalize

to produce sounds, as in some marine cetaceans that utilize the high speed of sound transmission in water to communicate

Narrowband Signals

span a narrow range of frequencies, last longer, and detect targets over long distances

Broadband Signals

span a wide range of frequencies, last less than 5 milliseconds, primarily aid in localizing targets