Flashcards
LEC165 continued
Cards in this deck (137)
- 1EVOLUTION OF FISH JAWS: - Development of ..... ..... that supported gill slits in ..... ..... jawless fishes - Bones of first ..... ..... became upper and lower jaws - Second ...... ...... moved forward to brace the jaws at back of jawsSkeletal rods; filter feeding; gill arch; gill arch
- 2CONTINUED: - Gradual change to become ...... jaws - Remaining rods disappear as gills assume ...... functionHinged; respiratory
- 3How much can Moray eels increase their mouth volume by?5x their resting volume
- 4In some fish the upper jaws don't protrude; what sort of feeding is it called when the upper jaw does protrude?Suction feeding
- 5What happens in the preparation stage of feeding?Increase in pressure, lifting mouth floor
- 6What happens in the expansion stage of feeding?Maximum suction, negative pressure up to -800cm H2O
- 7What happens in the cavitation stage of feeding?Water vapour coming out of solution, forming small vapour-filled cavities
- 8What happens in the compression stage of feeding?Pressure increase, opercular valve opens after jaws close, then recovery
- 9What size of items does this pipetting action caused by the protrusion of the upper jaw pull in (relative to head-length)?25-50% of head-length
- 10How much, percentage wise, does this increase the attack velocity by?~40%
- 11What is the name of the second jaw that the Moray eel possesses? What is the use of this second jaw?Pharyngeal jaw; used to crush and condense prey ready for digestion
- 12What are the 3 major methods of feeding?Ram feeding, suction feeding and manipulation feeding (accepting/rejecting at close range)
- 13What are the 2 types of searching methods that fish can use?Active searching and passive searching
- 14What happens in active searching? What senses does it use? What techniques do they use?Fish swims around, actively searching for food; use of all senses (vision, olfaction, gustation, hearing, touch, mechano & electro-reception); speculation searching (probe into potential hiding places) and actively flush prey out via some disturbance (e.g. turning over rocks)
- 15What happens in passive searching? What are some of the techniques that these fish use?Ambush/sit & wait predators; buried by sediment/camouflage; some passive water column predators hang in water column; some allow prey to habituate and/or use countershading; most use vision to detect prey
- 16What are the 2 methods of prey pursuit?Chasers and deceivers
- 17What are some features of chasers?Very streamlined; big fins and broad tails for quick braking and sharp turns; highly controlled swimming to catch prey in complex habitats; fast start predators; lie-in-wait predators; elongate bodies; can't maintain speed for long stretches
- 18What are some features of deceivers?Some use lures; predator's body camouflaged; predator sucks prey in and holds them with backward facing teeth; others stalk prey; approach prey head on and make use of disruptive coloration which disrupts outline to delay predator recognition
- 19Predator attacks by ..... prey with simultaneous mouth ...... and ......Overtaking; extension; suction
- 20What is the difference between the attack method of fast-start predators and benthic ambush predators?Fast-start predators overtake prey and target the prey's centre of mass (i.e. the part of the prey that moves the least) and benthic ambush predators typically have an enhanced capacity to engulf prey
- 21What are some other attack methods?Other fishes swim and feed on particulate prey either by ram filter feeding (e.g. basking sharks) or eating individual prey (e.g. herring feeding on zooplankton)
- 22What are some of the predators tactics when catching prey?Separate out individual prey from the shoal - improves probability of predation; attack stragglers/those that are different within the shoal; mimic shoal members or non-threatening species
- 23Therefore, what is there selection for within shoaling species?Selection for morphological and behavioural uniformity
- 24What is involved in the handing process/post capture manipulation? Why is it done?Aids in ingestion and digestion; removal of spines, toxic skins, etc.; reduction in prey size; large prey typically maneuvered to go in head first to allow prey fins/spines to be depressed and to reduce probability of escape
- 25What are some morphological adaptations for handling shown by: - piscivores - molluscivores - planktivoresPiscivores - needle-like teeth for holding/shredding prey
Molluscivores - molar-like grinding teeth
Planktivores: teeth typically reduced or even absent - 26What are the 5 main types of dentition found in pescivores?Long, slender, sharp; villiform, needle-like; triangular; caniniform, recurved, conical; cardiform, sandpaper
- 27What type of dentition do molluscivores have?Molariform, blunt conical
- 28How does pharyngeal apparatus differ for herbivores and molluscivores?Herbivored develop small papilliforms and molluscivores develop robust molariforms
- 29What do gill rakers do? What is gill raker spacing related to?They prevent the loss of prey through the operculum; spacing relates to the size of the prey (smaller spacing = smaller bodied prey)
- 30What are the 5 main ways in which fish can avoid detection?Camouflage (mimicry and disruptive coloration); countershading; silver coloration; transparency; shoaling
- 31Name 3 morphological adaptations that fish use to evade pursuitSpines; toxic skin/internal organs; making use of aposomatic coloration or behaviour (bright, conspicuous coloration and/or slow escape response)
- 32What are some other behavioural adaptations to evade pursuit?Finding shelter (structured environments, sediments and coral); evade through speed (outswim the predator or some fish can fly)
- 33Give one morphological adaptation and one behavioural adaptation of preventing/deflecting attack?Morphological - spines
Behavioural - group living - 34What is the dilution effect?The probability of an individual being eaten decreases with larger group size
- 35What is the confusion effect?Predators become confused by so many prey that they switch targets too often to catch many prey
- 36What other avoidance tactic do fish shoals use?Vertical migration to avoid predation from visual predators
- 37What is an adaptation of prey to discourage capture?Having a body shape that limits capture efficiency (e.g. through gape limitation) such as the conspicuous erection of spines when threatened
- 38Give some examples of morphological adaptations to discourage once capturedSpines that lock in position to prevent ingestion; thick skin; detachable scales; mucus production (shown by hagfish and toadfish); toxicity/venom (shown by fugu and weaverfish)
- 39Describe olfactory and gustatory sensing in terrestrial animalsOlfactory - stimulated by airborne molecules; sensitive and chemical-specific
Gustatory - stimulated by contact with dilute solution - 40How does this differ slightly for aquatic animalsBoth types of organs in fish have similar sensitivities to contact stimuli of chemicals in water; distinguished by location of sensory receptor and processing centre
- 41Describe olfaction in fishOlfactory receptors typically found in olfactory pits; these have incurrent and excurrent channels (nares); water flow induced by cilia, branchial movement and swimming; odour is perceived when dissolved chemical contacts olfactory rosette
- 42What is this stimuli connected via?Lateral or medial divisions of the olfactory bulb to the olfactory lobe of the brain via the first cranial nerve
- 43How do the olfactory cues differ in these aquatic animals?Cues imprinted upon salmonid presmolts and smolts; klinotaxis for food detection in sharks
- 44Where are the taste buds of fish found?Skin, fins, barbels, palatal organs, gill rakers & arches
- 45What is the acoustico-lateralis system used for and what are the two main components?Used for sensing sounds, vibrations and water displacements; two main components are the inner ear and the neuromast/lateral-line system
- 46How does the otolithic stimulation work?Semi-circular canals (horizontal, lateral & longitudinal); each contain fluid inertia-sensing chambers (ampullae); as sound vibrations impinge on a fish, the fish is displaced in the water; inertia of the comparatively dense otoliths cause a lag phase
- 47What is the otolith movement detected by?Ciliary bundles in a sensory epithelium (macula
- 48At higher frequency, amplitude of fish displacement ......Decreases
- 49What else can provide acoustical transformation?The swim bladderin conjuction with the Weberian ossicles
- 50What do the cartilaginous fish do that don't have swim bladders or otoliths?They have well developed endolymphatic ducts; often use exogenous materials as otolith substitute - some incorporate a sand grain within the body which they use in helping them detect sound
- 51What is the lateral line used for?Has mechanoreceptors (sensory hairs) that detect water movements in microcanals under the scales; the lateral line is a line of pores that allows water into these microcanals; they use this system for prey detection and obstacle avoidance
- 52Why do they think that electroreception has likely evolved independently?It is present in distantly related lineages of teleost fishes with a distant, common non-electroreceptive ancestot
- 53How does electroreception work?Teleosts have external pit organs which are connected to the external environment via canals filled with electrically conductive gel; marine elasmobranchs have 'ampullae of Lorenzini' (lines of nerves used to detect electric currents)
- 54What can some fish predators detect at ~1m?Extremely weak electrical currents from the depolarisation and repolarisation of contracting muscles
- 55How do sharks effectively act as an electromagnetic compass?Dorsal and ventral location of receptors moved across the Earth's N-S magnetic field should detect induced electrical fields
- 56How can we use that to protect us against sharks?Anti-shark screens for the US Navy and some surfers have special surf boards that give off confusing electrical signals
- 57Why do fish have a cornea of constant thickness?No optical alteration; all light focused at the spherical lens; highest refractive index
- 58What is the benefit of the fish eye bulging? How is the blind spot eliminated?Field of view arcs forward continues laterally to almost behind the fish; alternating head movements of anguilliform/subcarangiform swimmers with coordinated eye movements eliminates the blind spot
- 59What does the fact that the spherical lens is eccentrically located in the elliptical teleost eye mean?Lens-retinal distance varies; allows near-field vision in front and far-field vision to the side
- 60How does the elasmobranch lens differ from this?Tends to be flattened; ability to dilate or constrict pupils
- 61How is optical accommodation accomplished in teleosts and how is it accomplished in elasmobranchs?Teleosts - pulled inward by retractor muscles
Elasmobranchs - pulled outwards by protractor muscles - 62How does echolocation work in dolphins?Modification of the former nostrils; use melon structure in the head which is a big mass of fat to absorb the reflection of the echo from the prey's swim bladder - internal nares take this information to the acoustic window
- 63How is the structure of the melon related to its function?It is a gradient of fat: wax esters in the middle are denser than the triglycerides at the edges; focuses acoustic energy like a lens; made of adipose tissue as this has similar properties to water so less acoustic energy lost during transfer
- 64Echolocation in water vs airEcholocation in water takes less energy, pulses travel further, so is quicker than in air; sound travels ~4x faster in water than air; intensity of a frequency is higher in water than in air; sound attenuates quicker in air
- 65What is the range length of echolocation in water for a sperm whale compared to echolocation in air for a bat?Sperm whale: >1500m
Bats: ~2.5-62m - 66What are some complications with echolocation in water?Intense man-made noises (like a gun blast) drown out other sounds and could cause hearing loss; natural noises; interference (a ship's propeller miles away can mask a whale's call)
- 67What is the order (from closest to furthest away) of sensory perception ranges?Electrical perception; vision; pressure; smell; hearing
- 68How long ago did the Earth's oxygen reach concentrations comparable to that found today? What was this a consequence of?~2.2 billion years ago; a consequence of oxygenic photosynthesis by marine unicellular algae, the phytoplankton
- 69How much organic carbon a year gets produced through photosynthesis carried out by marine phytoplankton?~45 Gt
- 70How much of this carbon is exported to the ocean interior?16 Gt
- 71Where is there high productivity in the oceans?Ar fronts, currents and gyres
- 72How can subsidies affect the production in the ocean?Saharan dust travels to the Caribbean - adds micronutrients (stimulating production) but could also block out light (hindering productivity) so is intensity dependent
- 73What are the 4 things that the development of satellite imagery has meant?More extensive (over space and time) coverage; more detailed understanding of physical drivers; hence more accurate global budgets; reduced cost monitoring
- 74What is needed in conjunction with remote sensing?Ground truthing (taking physical samples from places indicated by remote sensing)
- 75What is the main way in which chemosynthesis occurs?Methanotrophy - oxidation of methane --> methanol --> formaldehyde --> formic acid --> carbon dioxide
- 76What is the area of oxygenated mud increased by?Burrowing fauna
- 77Where do the anaerobic exist and so where is the methane produced if the water is mixed? What about if the water is stratified?Mixed - sediment surface
Stratified - hypolimnion is anoxic and so oxic/anoxic interface occurs midway through the water column so methane is produced at this interface - 78Where do the organisms that live on the benthos therefore get the carbon to make up their biomass from?From seeps and vents that are producing methane - via chemosynthetic primary production
- 79........ are biogeochemical hot spots - receive large inputs of ..... and organic .... from land and oceans to support high rates of ..... and primary ........Estuaries; nutrients; carbon; metabolism; production
- 80How much carbon can phytoplankton make in their optimum environment in an estuary? What about in an estuary like the Scheldt estuary?2kg C/m2/y
-0.5kg C/m2/y - 81How can there be a negative value?Lack of light due to suspended sediment
- 82What are some of the main primary producers in an aquatic system?Phytoplankton; microphytobenthos; seagrasses; saltmarsh plants; bacteria (especially sulphur bacteria)
- 83How do coral reefs exist when the nutrient levels are low? How do we know that they are low?Works because of efficient symbiosis between polyps and zooxanthellae (symbiosome keeps conditions optimum for the exchange of ions); if the nutrient levels were high then the phytoplankton would take over
- 84What does the zooxanthellae supply the coral with?Glucose, oxygen, glycerol, amino acids and waste removal (in return for a protected environment and compounds they need to carry out photosynthesis)
- 85How much of the organic material photosynthetically produced by the zooxanthellae is transferred to the host coral tissue?Up to 90%
- 86How can we estimate the abundance and diet of all consumers?Stomach contents analysis; regurgitates; faeces, pellets; observations
- 87How does ontogeny affect food webs?Fish feed on different things at different stages of their life
- 88What does it mean if you draw a pyramid of energy and it isn't pyramid shaped?There must be subsidies at some trophic level
- 89What are some limitations with stomach contents analysis?Have to kill the animals; hard-bodied prey retained longer within the stomach; animal may regurgitate stomach contents upon capture if stressed; may consume microscopic prey; only a snapshot of the diet over ~1 day; may feed and pass food at different time intervals
- 90What are the two biochemical markers that we can use instead to see what these animals are eating and where they are eating them?Stable isotope ratios and fatty acid compositions
- 91The chemical composition of what 2 substances in particular are used to assess this?SIA - assimilated proteins and lipids
FAA - assimilated lipids - 92How has the use of stable isotope ecology changed over the years?Use has grown exponentially
- 93What fields can stable isotope ecology be used in?Physiology; trophic ecology; migration; behaviour; ecosystem function; evolution; individual ecology; microbial ecology
- 94Define isotopeAtoms of the same element with the same number of protons but different numbers of neutrons
- 95What are the 2 stable isotopes of carbon and what is the radioactive isotope?Stable - 12C and 13C
Radioactive - 14C - 96What can the following isotopes be indicators for? Hydrogen; carbon; nitrogen; oxygen; sulphurH - continental location; hydrology
C - energy source
N - trophic level
O - temperature; hydrology; continental location
S - salinity; catchment geology - 97How do you work out the delta values from raw ratios in stable isotope ecology?((Rsample/Rstandard) -1) x 1000
- 98What are the differences between d13C of CO2 and primary producers in air, fresh water and seawater?Fractionation differences (how easy is it to get CO2 into the cell) and differences in water chemistry (availability of other C sources)
- 99What is the d13C value of the atmosphere compared to that fossil fuels?Atmosphere: -8
Fossil fuels: -27 - 100What's the difference between radioactive isotopes and stable isotopes within a system?Stable isotopes are conserved within a system whereas this is not the case with radioactive isotopes
- 101Heavy stable isotopes often become concentrated (fractionated) following chemical reactions, including biological processes. Name some of these processesPhotosynthesis; assimilation; excretion; respiration; nitrification
- 102Why do products end up with more of the light isotope and less of the heavy isotope?'Harder to push the extra neutron up an energy hill'
- 103What does a higher delta value indicate and what does a lower delta value indicate?Higher = are relatively enriched in the heavy isotope and are 'heavier'
Lower = are relatively enriched in the light isotope and are 'lighter' - depleted in the heavy isotope - 104What happens to the delta value for carbon if one organism eats another?There carbon value is one higher than that of the prey
- 105What happens to the delta value for nitrogen if one organism is on the next trophic level?There nitrogen value is 3.4% higher than that of the organism on the lower trophic level
- 106What can we work out by looking at the stable isotope values of whale baleen?Because whale baleen grows slowly over time, by looking at the stable isotope values over different lengths you can work out where it's been and what it's been eating over its lifetime
- 107What as indication of long-term decline in baseline δ13C and δ15N over time in whale baleen likely reflect?Likely reflects reduced upwelling intensity
- 108What would we look at if we wanted to see what an animal has been eating and where it has been over the past few days?The liver and plasma cells
- 109What would we look at if we wanted to see what an animal has been eating and where it has been over the past few weeks/months?Muscle/blood cells
- 110What would we look at if we wanted to see what an animal has been eating and where it has been over the past few months/years?Feathers/hair
- 111What does the penguin data show after carrying out stable isotope analysis?That the diet has moved away from from fish and moved more towards krill in the last century
- 112What does the timing of this abrupt shift to krill coincide with?The rapid deletion of whales and seals from the 18th to 20th century in the Southern Ocean
- 113What is cheaper out of stable isotope analysis and gut contents analysis?Stable isotope analysis is the same cost per sample dependent of how many individuals are found within the stomach (around 18 dollars); gut contents analysis increases as the number of individual species found increases (can go up to 110 dollars per sample)
- 114How much detail can the stable isotope analysis go into?Can tell you what group of organisms the animal is eating but cannot give taxonomic/species-level detail
- 115Why is fatty acid analysis less common?Complex separation steps (gas chromotography --> combustion --> mass spectrometry) and the associated costs are higher (about £95 per sample)
- 116Why are fatty acids important molecules?They provide energy resources and essential nutrients for survival and growth; integral components of cell membrane structure and function
- 117How much detail can FAA go into?Taxon-specificity (different primary producers produce different fatty acids)
- 118Do the fatty acids change as they go through the trophic levels?Transferred from primary producers to higher trophic levels without major changel generally remain intact through digestion, absorption and transport in the bloodstream, and are then taken up by tissues in their intact state
- 119What is the difference in fatty acids found in bacteria and phytoplankton compared to higher organisms?Bacteria and phytoplankton have the ability to synthesise complex fatty acids from simple chains but higher organisms do not
- 120Why are coastal areas and estuaries at higher risk than the open ocean?They are in close association with where humans are
- 121Why is there an observed reduction in surface warming trend over the period 1998-2012?Internal variability, including a possible redistribution of heat within the ocean' reduced trend in radiative forcing (volcanic, solar)
- 122When do climate change models only match the observations?When anthropogenic forcings are included (rather than just looking at natural projections)
- 123How is climate change affecting species distribution?Causing some species to shift their habitat location latitude-wise; 1 new species a year has been recorded in Cornwall since 1980
- 124What causes coral bleaching?Increased ocean temperatures; increased runoff and pollution; overexposure to sunlight; extreme low tides (so more exposure to the air)
- 125How will sea level rise affect different habitats?Beaches - overwashing/increased erosion
Unconsolidated cliffs - erosion
Estuaries - increase in tidal volume
Freshwater marshes - gradually become salt marshes or migrate landward - 126What is coastal squeeze?Would normally get successional movement of coastal habitat but if there is an impermeable barrier (such as a flooding barrier or caused by things such as dredging) then this natural succession cannot occur
- 127What does coastal squeeze cause?Loss of buffering habitats (mangroves, sea grasses and saltmarshes); altered runoff characteristics from land; increased nutrients and pollution
- 128How can these buffering habitats be lost?By physical re-movement or excess exposure to nutrients
- 129What does soil loss (caused by the intensive farming of bananas for example) cause in estuaries?Sediment blocks light to photosynthesizing plants and adds excess nutrients
- 130How much of all coral reefs world wide are at high or medium threat from inland pollution and soil erosion? When combined with the effects of bleaching, what is the recent estimate of costs to the ecosystem services and tourist industry?22%; 1 trillion dollars
- 131What has increased drastically over the last 30 years?Aquaculture production (is now same level as wild capture of fish)
- 132What are downsides to aquaculture (6 factors)?Some fish escape & are more vulnerable to predation or may be genetically engineered; fish waste could add potentially harmful extra nutrients to the water; predators can get entangled in the nets; disease & pests can multiply in these nets & spread to water; wild fish can be affected by drugs used; fish food needed in vast quantities (as is caught in wild can affect other ecosystems)
- 133What does the absorption of CO2 by the oceans cause?Ocean acidification
- 134How much (%) has the ocean's pH decreased by already? If we carry on, how much will ocean acidity increase by 2100? What are some major effects of ocean acidification?~30% decrease; 150% increase; loss of calcium carbonate so less coccolithophores which are very important for photosynthesis; if marine algal structure impacted then this could affect the pelagic-benthic coupling
- 135Give an example of a fish that has been over-exploitedThe orange roughy; doesn't mature til 23-40 years old so were being caught before this age causing a population crash
- 136What is the effect of removing higher predators, give an example of thisPotential to induce 'trophic cascades'; by fishing sharks causes a crash in the scallop population as shark prey increase due to less predation which feed on these scallops
- 137How deep in the ocean have plastics been found? What is the predicted percentage of seabirds that will have ingested some plastic by 2050?As low as 5200 metres; 99%
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- BIOLOGY DEGREE LEVEL (LEC165) Flashcards on LEC165 continued, created by Anna Hollywood on 17/05/2017.
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