lecture 4 cards Flashcards
G.E. Hutchinson
Created the idea of the n-dimensional hypervolume and fundamental vs realized niches, also paradox of the plankton
Fundamental niche
N-dimensional space that an organism theoretically occupies
Realized niche
Actual space that an organism occupies, usually restricted by biological interactions
Gause
No two species can occupy the same niche
Paradox of the plankton
How can so many species occupy the seemingly homogeneous mixed layer of a lake or ocean if the principle of competitive exclusion is correct? Either there are so many niches that it seems like they are in equilibrium, or they are NOT in equilibrium
Adaptations
Special inherited features that enable a species to function in its niche
Acclimatization
Changes in tolerance with seasonal environmental change.
Acclimation
Compensatory process involving a shift in a function following an environmental change. Has to do with when an org moves from one place to another and has to deal with a new environmental regime.
Density independent growth
Number of individuals times birth rate minus death rate
Exponential growth
dN/dt = rN
Density dependent growth
There are limits to growth, including the carrying capacity K.
Logistic Equation
dN/dt = rN (K-N/K)
Life tables
Include birth and death rates and average numbers for different ages or stages in a population
Survivorship curves
A function of growth rate, death rate, life expectancy and fecundity, the number of organisms alive at any time t
R-selection
Growth rate can expand rapidly when more resources are available
K-selection
Balanced growth rate and death rate in that they don’t have expansive growth rates when there are more resources, etc
MacArthur and Wilson
Published Island Biogeography, where r-selection and k-selection were used for the first time
Intraspecific competition
Competition between individuals of the same species
Interspecific competition
Competition between individuals of different species
Interference competition
Access to a resource is denied to competitors by the dominant individual or species
Exploitative competition
The direct use of a resources that reduces its availability to a competing individual or species simply by consumption
Coefficient of competition
a12 or a21
a12
The effect of species 2 on species 1
a21
The effect of species 1 on species 2
Connell famous study
Balanus and Chthamalus where Cthamalus tolerates drying more but is outcompeted by Balanus at lower heights. Balanus is larger and faster growing and can lift, cover or crush Cthamalus
Holling curves
Functional responses to prey density. Includes rate of successful search for prey, search and handling time, hunger level of predator, and inhibition of predation by prey
Rate of successful search for prey
Relative mobility of predators and prey, size of perception field of predator, proportion fo attacks resulting in capture
Search and handling time
Time spent persuing and subduing prey, eating prey and in digestive pause
Hunger level of predator
Rate of digestion and assimilation, gut capacity
Inhibition of predation by prey
Behavioral and morphological adaptations of prey
Commensalism
Benefits one side of the interaction
Mutualism
Benefits both sides of the interaction
Parasitism
Benefits one side at host’s expense
Factors affecting diversity
Time, spatial heterogeneity, competition, environmental stability and predation
Neuston
Animals attached to the air-sea interface, includes bacteria, protozoa, algae and larger animals like jellyfish
Nekton
Animals that swim
Holoplankton
Spend entire life in open water, no benthic stages
Meroplanktonic
Organisms that spend part of their lives in the plankton and part in the benthos, and species that require benthic resting stages
Tychoplanktonic
Organisms normally attached to substrate but they may be occasionally broken off and thus float in the plankton
Cyanophyta/Cyanobacteria
Prokaryotic, no organelles, cell walls are mucopolysaccharides, can glide but no flagellae, some filamentous forms have heterocysts. Species include Synechocystis and Synechococcus, Tcihodesmium which is colonial, can cause red tide outbursts
Heterocysts
Special cells with thick walls which are centers of nitrogen fixation
Chlorophyta
Green algae, mostly macroalgae near the shore, cellulose cell walls
Prasinophyta
Different from green algae because different flagellae, cell wall is organic scales, includes Pyramimonas and Micromonas
Synechocystis
Cyanophyta
Synechococcus
Cyanophyta
Trichodesmium
Cyanophyta, colonial
Pyramimonas
Prasinophyta, alternates between flagellate cell and benthic stage
Micromonas
Prasinophyta, common in the plankton
Chrysophyta
golden algae, have chlorophyll a, c and carotenoid, capable of phagotrophy, some have silica scales, include Distephanus and Dictyocha fibula
Phagotrophy
Gaining nutrition from consuming other organisms
Mixotrophs
An organism that can photosynthesize and engulf cells
Distephanus
Chrysophyta that have internal silicon skeletons
Dictyocha fibula
Chrysophyta that was used as a clone to evaluate the classification system used by paleontologists
Haptophyta or Prymnesiophyta
Include coccolithophores, in colonies or filaments, same as chrysophyta but different flagellae, include Phaeocystis, Emiliania
Phaeocystis
Forms gelatinous colonies, important in polar seas, blooms can affect migration patterns of fish
Emiliania huxleyi
Cells covered in calcareous plates
Xanthophyta
Yellow-green algae, similar to chrysophyta but lack the carotenoid, include Olisthodiscus
Olisthodiscus
Xanthophyta that is cultured as food for oysters, lives in brackish waters
Cryptophyta, or cryptomonads
Biflagellate cells,store starch, have ejectosomes that line the gullet, include chroomonas
Chroomonas
Cryptophyta, common species
Euglenophyta
Unicellular flagellates with chlorophyll a and b, have distinctive eyespot, flexible cell wall covering. Include Eutreptiella
Eutreptia
Euglenophyts that are marine
Bacillariophyta
Diatoms, most important group of phytoplankton in terms of primary productivity. Mostly unicelllular, chlorphyll a and b and fucoxanthin, produce oils that may provide buoyancy. Contain frustules, silica cell walls. When they reproduce, population becomes smaller. Pennate diatoms have a raphe system, longitudinal slit.
Frustules
Silica cell walls of bacillariophyta
Auxospore
Zygote of a bacillariophyta
Pseudonitzschia pungens
Diatom that creates amnesiac shellfish poisoning
Pyrrophyta
Dinoflagellates, unicellular with 2 flagellae. Majority of unicellular flagellates in the ocean. Whirling, spinning motion. Produce chlorophyll a and c, peridinin. Storage products are starch and oils. About half are colorless, som are parasitic, many are mixotrophic, some are bioluminescent. Some responsible for red tides. Can be responsible for fish kills.
Zooxanthellae
Non-motile spores
Hermatypic corals
Reef-building corals
Gymnodinium
Pyrrophyta lacking walls
NSP
Neurotoxic shellfish poisoning in gulf of mexico, due to pyrrophyta
PSP
Paralytic shellfish poisoning, worldwide, due to pyrrophyta
DSP
Diarrhetic shellfish poisoning, worldwide, due to pyrrophyta