Functional marine biology Flashcards
What is functional biology?
Function refers to the way organisms solve problems and how physical and chemical factors constrain and select solutions.
What is the law of tolerance?
Each individual has a range of tolerance for every physical variable. The distribution of a species is controlled by that environmental factor for which the organisms have the narrowest range of tolerance.
What is homeostasis?
The tendency towards a relatively stable equilibrium among interdependent elements
What is stress?
A state produced by an environmental or other factor which extends the adaptive responses of an animal beyond the normal range
What are different sources of stress?
*age
*disease
*parasitism
*water quality
What are thermodynamics?
The relationship between temperature and a reaction. Q10 describes this relationship in biological processes
What is Q10?
The temperature coefficient. It represents the factor by which the rate of a reaction (R) increases for every 10°C rise in temperature (T).
Why does Q10 contradict the Arrhenius equation?
The Arrhenius equation describes the relationship between temperature and a reaction rate in a chemical state. It shows there should only be a 2% rise in rate of reaction for a 10°C rise. Q10 contradicts this because biological systems represent the summation of many individual reactions, which are catalysed by enzymes
What is the role of enzymes on thermal tolerance?
Enzymes increase the efficiency of biological reactions. Increasing temperature means there is more kinetic energy so more collisions but after a certain point enzymes begin to denature.
What is a eurytherm?
A species with a wide temperature range - this means they may have a wide geographical distribution
What is a stenotherm?
A species with a narrow temperature range
What is a poikilotherm / ectotherm?
A species with body temperature equal to the seawater temperature
What is a homeotherm / endotherm?
A species who’s body temperature is constant and controlled
What is the difference between a regulator and conformer?
Conformers don’t regulate their body temperatures whereas regulators do. Regulators have a zone of stability where homeostasis is maintained
What are poikilothermic eurytherms?
They have a wide temperature range but don’t regulate their own temperature so match outside temperature conditions. They are found in lots of different geographical temperature areas.
What are poikilothermic stenotherms?
They don’t regulate their own body temperature and have a narrow temperature range. Found in a small geographical temperature range.
Stenothermy can often give rise to striking separations of species’ ranges, even on very small spatial scales.
What is adaption?
The genetic process by which a population changes to accommodate environmental factors
What is acclimation?
The physiological changes an individual makes to minimize the effects of stressors. Does not require genetic modification, only physiological changes.
What is acclimatisation?
A coordinated response to several simultaneous stressors (e.g. temperature, humidity and photoperiod). , perhaps due to moving to a new geographical area
What are different poikilothermic adaptions?
*Intertidal polychaetes burrow into sediments to avoid over-heating
*Purple sea stars pump themselves up with cold seawater prior to being exposed at low tide
*Some antarctic fish have clear blood because instead of synthesizing blood hemoglobin, they produce antifreeze glycoproteins allowing them to swim in polar regions up to -1.8 degrees
How is heat conserved in fish?
Most fish are true poikilotherms but a number of large fish maintain above-ambient core temperatures using counter-current heat flow exchange.
What are examples of insulation in aquatic vertebrates
*Dolphins have heat exchangers in their finns
*Whales have heat exchangers in their tongue
*Aquatic birds have heat exchangers in their legs
What is osmoregulation?
The active regulation of osmotic pressure of body fluids
What is excretion?
The process of removing metabolic waste
What do aquatic animals secrete?
Aquatic animals secrete ammonia. They have excess of hydrogen as they are surrounded by water so they utilize 3 H atoms for waste
What do ureotelic animals secrete?
Ureotelic animals secrete urea and utilize two H atoms as they only have a steady flow of water
What do uricotelic animals secrete?
Uricotelic animals use 1 H as they have a limited supply of water E.g. birds
How does a high water potential e.g. pure water affect plant and animal cells?
Water moves into the cell by osmosis down a water potential gradient. Animal cells are cytolysed and burst open. Plant cells have a cell wall which prevents bursting but the membrane pushes against the cell wall and it becomes turgid.
How does low water potential e.g. concentrated sugar solution affect plant and animal cells?
Water moves out of the cell by osmosis down a water potential gradient. Animal cells shrink and appear wrinkled and become cremated. Plant cells membranes pull away from the cell wall and becomes plasmolysed.
Where did animal life begin?
Animal life began in the sea where it flourished because of the relative consistency of the environment for example salt concentration. The body fluids of most marine invertebrates have a similar composition to that of the seawater.
What is the osmotic concentration of most marine animals?
Osmotic concentration is close to that of their medium (seawater) and do not experience significant water losses or gains
What are osmoconformers?
Species whos overall osmotic concentration is always approximately isosmotic with seawater. Most marine invertebrates are osmoconformers.
What are osmoregulators?
Species that regulate the ionic and osmotic composition of their body fluids to maintain a stable (within limits) internal fluid composition. For example migratory fish and some estuarine invertebrates
What techniques do osmoconformes use to be isosmotic with seawater?
*Body volume changes as water enters or leaves by osmosis
*Some animals burrow into sediments to avoid rapid changes in external salinity.
What are euryhaline animals?
Animals which can tolerate a wide range of salinities, usually by a combination of osmoconforming and osmoregulatory processes; most estuarine species
What are stenohaline animals?
Animals which are restricted to a narrow salinity range. They still have active ionic and osmotic regulators; most marine teleosts
How do animals regulate osmotic pressure?
Cells are isosmotic to body fluids, but have a different ion composition (higher K+ & lower Na+). If the osmotic concentration of body fluid changes, this is matched by changes of organic molecules in cells; Organic molecules, mainly amines and amino acids are used inside cells as osmotic regulators.
What amino acid do most marine invertebrates use for osmotic regulation?
glycine
Why cant all amino acids be used for osmotic regulation?
Some amino acids cant be used for osmotic regulation intracellularly as they interact with proteins and change their conformation. e.g. lysine and arginine are not found in the same concentration as osmotically important amino acids.
What is salinity-mediated osmoregulation?
The concentration of free amino acids in cells is regulated by changing levels of protein degradation or synthesis. These levels increase during salinity stress and are consistent with cell volume regulation
What are the 3 types of osmotic marine vertebrates?
*Iso-osmotic with seawater: e.g. Myxine (hagfish)
*Hypo-osmotic regulators (with a higher concentration of body fluid than surrounding): most marine vertebrates
*Air-breathing marine vertebrates (with no gills)
What technique do elasmobranchs use to maintain iso-osmotic pressure with seawater?
Elasmobranchs (e.g. dogfish) retain large amounts of urea in their body fluids. Although they have lower salt content than seawater, increasing the urea concentration makes them iso-osmotic. The urea is used in the coelacanth and liver
How do organisms that live in both freshwater and saltwater regulate osmotic pressure?
salmon migrate between oceans and freshwater
At sea they drink seawater, excrete salt from gills and produce little urine. In freshwater they stop drinking, take in salt via gills and produce lots of dilute urine.
How do the Air-breathing marine vertebrates birds and reptiles regulate osmotic pressure?
They face more problems than fully terrestrial species as no freshwater to drink & high salts in food (algae & invertebrates isosmotic to seawater). Birds and reptiles have salt glands in the head that secrete hyperosmotic NaCl solution.
What is special about Pelodiscus sinensis - the Chinese swamp turtle
Its the only vertebrate that excretes urea from its mouth. its an adaptation to brackish water
How do the air-breathing marine vertebrates mammals regulate osmotic pressure?
They are able to form hyperosmotic urine (i.e. more concentrated than seawater). This allows removal excess of salts from food or ingested seawater; humans do not have this ability hence the inability to drink seawater
What is the mechanism of excretion in invertebrates?
Lower invertebrates such as Porifera still rely on diffusion to remove nitrogenous waste. Higher invertebrates have a tubular filtration system
What are the processes of a tubular system?
*Filtration
*Selective reabsorption and secretion
*Excretion
What is bioenergetics?
The study of energy flow through living systems
What is respiration?
Respiration includes the transport of oxygen into the body/cells and transport of carbon dioxide out of the body.
What is metabolism?
Metabolism includes the cellular processes by which energy is obtained through the breakdown of glucose (includes cellular respiration).
What are the steps of aerobic respiration?
It starts with glycolysis in the cytoplasm where a glucose molecule is broken down into pyruvate. If there is sufficient oxygen for aerobic respiration, pyruvate is transported to the mitochondria where it is converted into ATP through the Krebs cycle. ATP is then created in the electron transport chain. The end products are ATP, CO2, and water. Oxygen is an electron acceptor at the end.
What are the steps of anaerobic respiration?
It starts with glycolysis where a glucose molecule is broken down into pyruvate. If there is insufficient oxygen for aerobic respiration, pyruvate is converted into lactate
What is steady state locomotion?
“Cruising”/”Routine” behavior: Fueled aerobically, primarily using red muscle fibers. It can be sustained for long periods of time.
E.g. Fish swimming around the reef or
Humans going for a light jog
What is unsteady state locomotion?
Sudden, intense exertion: Fueled anaerobically, primarily utilizing white muscle fibers. It causes lactate accumulation so cannot be sustained for a long period of time
This can lead to fatigue
How do birds save energy during locomotion?
Social behaviours such as flying in a v formation where the following birds take advantage of air upwash/ downwash that is produced by the leading bird´s wing pattern (creating greater aerodynamic efficiency)
How do schooling fish save energy during locomotion?
Fish take advantage of eddies produced by leading fish (creating greater hydrodynamic efficiency)
What is metabolic rate?
The rate at which an animal consumes energy.
What factors influence metabolic rate?
*Intensity of physical activity
*Temperature of the environment
*Diet
*Age
*Weight
*Hormones
What is specific dynamic action (SDA)?
Increase in metabolic rate caused by food ingestion
What is a requirement of measuring standard metabolic rate (SMR)
Animals must be fasted prior to experimentation to avoid variability associated with SDA. They are in a postabsorptive state
What is the relationship between metabolic rate and body size?
Larger animals in general have high absolute metabolic rate than smaller animals. However, this increase in metabolic rate is slower than linear (1:1)
What is hypoxia?
Episodes of low dissolved oxygen following natural or anthropogenic factors. Oxygen solubility declines at warmer temperatures, so hypoxic events exacerbated by climate change
What techniques do marine organisms use to cope with hypoxia
*Enhance oxygen uptake, transport, and delivery
*Rely more heavily on anaerobic metabolism
*Depress their metabolic needs for lower reliance on aerobic metabolism
What methods are used to measure metabolic rate?
*Direct calorimetry
*Indirect calorimetry
*Respirometry
*Field metabolic rate
What is direct calorimetry?
It measures heat production. It can measure both aerobic and anaerobic metabolism.
It is the most accurate method but is technically and logistically difficult, and expensive
What is indirect calorimetry?
It measures the chemical energy content of the organic matter that enters (i.e. food) and leaves an animal´s body (i.e. urine and feces) as a proxy for metabolism.
Uses a technique called a bomb calorimeter, which measures the energy in organic materials, by burning the materials under pure oxygen conditions, and measuring the heat released
What is respirometry?
Measures an animal´s rate of respiratory gas exchange, particularly oxygen consumption, as a proxy for aerobic metabolism
What is field metabolic rate measurement?
Metabolic rate is measured in a free-roaming animal. Biologgers can be used to measure movement and heart rate.
What medium, air or water has a higher concentration of O2?
The amount of O2 is dramatically lower in water than air because it depends on the solubility of O2 in water, and O2 is not particularly soluble. Water is 800x denser than air therefore greater mechanical work is required to move across exchange surfaces
What medium, freshwater or seawater has a higher concentration of O2?
Freshwater as warmer, more saline water has lower solubility as less O2 dissolves
What is the relationship between habitat mediums and movement of fluid in organisms?
Because of waters greater density and viscosity, water-breathing animals must generally expend more energy than air-breathing ones to move a given volume of fluid through their respiratory passages
Why are there no fully homeothermic (warm-blooded) water-breathers?
Heat capacity water is x3000 that of air. For the same amount of O2 taken up, a water breather is exposing itself to a heat sink x90,000 greater than for air breathers so there are none.
What are the two mechanisms of gas exchange
*Diffusion
*Convection (ventilation or circulation)
What is a dual/bimodal breather?
They can breathe air or water and often have at least two respiratory structures
What are the 3 types of specialised breathing structures?
*Lungs
*External gills
*Internal gills
What is Fick’s law of diffusion?
It determines the rate at which diffusion will occour. The rate of diffusion is proportional to both the surface area and concentration difference and is inversely proportional to the thickness of the membrane
How can marine organisms speed up diffusion?
They can use countercurrent exchange rather then cocurrent as the blood reaches a higher O2 partial pressure because blood exchanges with fresh medium (water) just before leaving the gas-exchange membrane
What is buccal-opercular pumping?
In bottom dwelling sharks and rays there are well- developed spiracles that allow water to be drawn into the buccal cavity and then forced over the gills. Spiracles sustain mouth-bypassing ventilatory flow to the gills when the subterminal mouth is obstructed by substrate or engaged in prey manipulation
How do rams ventilate?
When swimming fast, they hold their mouth open and flow from forward motion ventilates gills. This has a lower metabolic cost of ventilation
What are some adaptations to improve efficiency of gas exchange?
*maximizing surface area:volume ratio
*Gill and lung structures
*Circulatory systems
What is feeding?
gathering and ingestion of food
What are autotrophs?
They are able to make their own food and energy from chemicals in their environment
What are heterotrophs?
They must obtain nutrients from other plants or animals for energy and nutrients.
What is the relationship between food web length and energy?
Short food chains deplete less energy prior to consumption, compared to long food chains.
What are small particle feeding methods?
*Suspension (filter) feeding: consumption of material suspended in water
*Deposit feeding: Ingestion of living and non-living organic matter
What is large particle feeding methods?
*Herbivory: Ingestion of living algal or plant material
*Predation: Ingestion of animal material
What is fluid feeding methods?
*Piercing and sucking of plant/animal juices
*Direct uptake of dissolved organic matter (DOM)
*Gain of sugars from symbionts
What is the feeding method of porifera?
They are filter feeders. They feed on very fine plankton and have choanocyts which move flagella to draw in water through pores
How is muciciliary used in filter feeding?
Motile cilia and mucus can be used to capture food particles of the appropriate size.
What is the feeding method of Amphiuridae spp. - brittle stars?
They are filter feeders. They feed by holding their arms into the water column and trapping particles in flowing water. Particles are moved to the mouth using groove on their oral side. In stagnant water they switch to deposit feeding.
How is setae used in filter feeding?
They are found o n appendages and used to collect food particles which they transfer to their mouth for ingestion.
What is the feeding method of baleen whales?
They are filter feeders. They have two sets of baleen plates made of keratin and a thick fibrous mat which sieves food particles from the water.
What is the feeding method of basking sharks?
They swim with their mouth continuously open to feed on zooplankton. Gill rakers trap and filter out plankton
How do deposit feeders and detritivores feed?
They consume large amounts of organic matter within sediments. They are vital for the regeneration of nutrients and enhance benthic productivity
How are radula use in feeding?
They are used to scrape algae off rocks or flesh off dead organisms
How is Aristotle’s lantern
used in feeding?
It is specific to sea urchins which are herbivores. It is a muscular teeth like system which allows urchins to scrape algae off rocks for digestion
How do predators use hunting behaviour to feed?
A lot of species have a target prey and can change their hunting techniques depending on the species of prey. E.g. whales/orcas hunt in pods and use wave washing to push seals off of ice and dolphins hunt in pods to trap fish with their tales or mud nets.
How do predators use a specialised radula to feed?
Drill snails have a radula that can cut holes through shell and then either sucks out living tissue or injects venom to paralyze their prey
How are nematocysts used in predator feeding?
They are only found in cnidaria which dont have a hard shell so use the nematocyst for protection. It is a coiled, barbed thread that quickly turns outward and often contains venom. They can be used for both prey capture and defense.
How do sea turtles feed?
They are both herbivores and carnivores and have a different beak shape depending on what they feed on.
What is photosynthetic symbiosis?
Endosymbiotic algae produce nutrients through photosynthesis which can be passed on to the organism e.g. coral. Also, the coral emits waste products which is consumed by endosymbiotic algae
What is chemosynthetic symbiosis?
E.g. hydrothermal vent worms which get sulfide from vent fluids which they use for energy
What is digestion?
The breakdown of food molecules by enzyme action into smaller chemical components that an animal is capable of distributing to the tissues of its body.
What is intracellular digestion?
Organisms have a gastrovascular cavity which only has one opening which serves as both mouth and anus. Food particles engulfed by cells lining the gastrovascular cavity and are broken down in the cytoplasm. Most soft bodied animals use intracellular digestion
