Interactions and Organism Roles Flashcards
Chemotaxis
Movement toward high or low chemical concentration
Phototaxis
Movement toward light
Geotaxis
Movement in response to gravity
Phobic Responses
Movements away from stimuli
Basic Interaction Types
Exploitation, competition, mutualism, commensalism, amensalism, and neutralism
Most Common Mutualistic Interactions
Syntrophic assemblages of anoxic microbes,
gut microbes, and nutrient remineralization
Succession and Seasonal Cyclical Change
Most marked in wetlands, which are very dynamic systems
Abiotic Factors
Especially influential in structuring aquatic communities
Characteristic Organisms
Inhabit a specific part of a habitat; varies daily and seasonally
Habitats
Sometimes defined by the communities that live there, for example, coral reefs, kelp forests, seagrass meadows
Aquatic Diversity
Tends to be most diverse in shallow areas; the other notable location is by the hydrothermal vents
Aquatic Decomposers
At the greatest abundance in the sediment
Zonation
Changes in physical and biological structure of a community, specifically when moving across a landscape // Results from changes in abiotic factors across that landscape
Sub-Tidal Zone
Goes up until the low tide mark; for obligate aquatic animals
Inter-Tidal Zone
Goes up until high tide mark; species that are adapted to changing water conditions (i.e. exposed to air versus in the water)
Supra-Tidal Zone
Animals that are adapted to breath air, because the tides do not really reach there; mostly terrestrial animals
Salt Marsh Zonation
Habitats defined by grasses and hedges to those defined by trees and shrubs
Succession
Temporal change in community structure; seen in all ecosystems, often the result of a disturbance
Pioneer Species
Small size and shorter lived, high growth rates, high dispersal and colonization rates
Late Successional Species
Larger and longer lived, slow growth rates, low dispersal and colonization rates
Primary Succession
Occurs in an unoccupied area; happening in the Great Garbage Patch, new life forms of bacteria and smaller organisms
Secondary Succession
Occurs in previously occupied areas due to disturbance, partial or complete; what is happening in Canada with forest fires
Regime Shift
Large and persistent changes in an ecosystem; often results in a less desired ecosystem state
Niche
A species’ role in its ecosystem, as defined by the environment in which it persists and the resources it uses
Fundamental Niche
Potential niche in absence of interactions
Realized Niche
Actual niche due to influence of interactions, so not necessarily the full range, determined by competitive species and other factors
Direct Effect
Interactions between two species that do not involve any other species, e.g. what we see in the food web
Indirect Effect
Interactions between two species that involve other species, often seen in trophic cascades
Behavior
Change in activity based on a response to an external or internal stimulus; all the ways organisms interact with their environment, species, and community
Behavior Types
Include instinctual/innate, learned, and abnormal
Intraspecific Interactions
Between individuals within the same population, e.g. social behaviors, resource competition, territoriality // Interference versus scramble competition
Interspecific Interactions
Between individuals of a different species within a community, e.g. predation, resource competition, mutualism
Reciprocal Effects of Interactions
Positive, detrimental, or no effect
Amensalism
Detrimental to one species but doesn’t affect the other (e.g. algal blooms and fish)
Commensalism
Helps one species while not affecting another species (e.g. clownfish and anemones)
Mutualism
Mutually beneficial relationship, results in enhanced survival, growth, or reproduction for both species, occurs less often in freshwater, characterized by benefits received, degree of dependency, degree of specificity, and duration of interaction
Predation
One organism feeds on another organism, typically results in the death of the prey // Carnivory, herbivory, or omnivory // Generalist or specialist
Predator Defenses
Cryptic coloration, object resemblance, mechanical defenses, behavioral defenses, chemical defenses
Diurnal Migration
Vertical migration based on the time of day // two hypotheses for why this happens, either for growth rate or predator avoidance
Herbivory
Type of predation involving consumption of primary producers, so in aquatic organisms, either plant phytoplankton or large plants // Mostly invertebrates eat phytoplankton, and a lot of taxa will eat large plants
Searchers
Time is spent locating prey, typically generalists and opportunistic
Pursuers
Time is spent chasing prey, more specialized
Ambushers
Time is spent waiting for prey, generalists
Filter Feeders
Filter food from the water, variety of taxa from sponges to whales
Deposit Feeders
Gather food from the sediment, benthic organisms
Deep Diving Taxa
For food, refuge, or navigation // Need several adaptations to deal with deep sea
Deep Diving Adaptations
Temperature regulation, collapsable lungs and air bladders, oxygen storing muscles, ultra sensitive eyes and other sensory appendages
Parasitism
One species feeds on another without killing it outright, generally during a long duration; thus the other species serves as the habitat
Parasitoidism
One species feeds on another for a long duration and eventually kills the host
Interspecific Competition
Detrimental to both species, often the result of sharing a limited resource, affects their carrying capacity (K)
Carrying Capacity (K)
The maximum sustainable population size based on available resources
Consumption Interspecific Competition
Consuming a shared resource
Preemption Interspecific Competition
Often with barnacle species, and sessile species, taking a wanted location
Overgrowth Interspecific Competition
Preventing resource access by growing over another
Chemical Interspecific Competition
Growth inhibitors or toxins kill/maim another organism
Territorial Interspecific Competition
Behavioral exclusion from another space
Encounter Interspecific Competition
Non-territorial interactions still negatively affect species
Interspecific Competition Behaviors
Encounter, territorial, chemical, overgrowth, preemption, consumption // also the distinction between scramble vs interference
Competitive Exclusion Principle
Two species cannot occupy the same fundamental niche
Niche Partitioning
Allows the coexistence of species due to different patterns of resource use
Keystone Species
Substantially impacts the structure of their communities regardless of their population size, removal often results. in loss of diversity, often has a disproportionate effect on the community (larger effect than number of organisms)
Ecosystem Engineer
Type of keystone species that also alters the structure of their habitat (e.g. beavers)
Trophic Cascades
Indirect effects in a community, usually triggered by predators, yet can also by initiated by non-predator interactions
Types of Trophic Cascades
Density-mediated, Trait-mediated and Bottom-up or Top-down
Passive suspension feeders
collect food by means of morphological structures that protrude into the flow and capture particles
what are examples of passive suspension feeders
gorgonian corals and sponges
Active suspension feeders
generate their own water currents to channel and ingest particles
what are examples of active suspension feeders
polychaete annelids and bivalve mollusks that have ciliary currents to draw particles toward cilia
Particle Selectivity by Suspension Feeders
can sneeze and what not to remove sand particles or sediment, and can select for nutritionally valuable particles before entering the gut as well
How does deposit feeding work in soft sediments
deposit-feeding macrobenthic animals ingest sediment and derive nutrition mainly from microalgae and particulate organic matter, can swallow sediment, can gather with tentacles, can siphon sediment grains, etc
What is sediment composed of?
complex mixture of inorganic material, microorganisms, decomposing organic material, and pore water with dissolved constituents
Territoriality
the maintenance of a home range that is defended, often INTRAspecific, for feeding, breeding, or nesting
How do predators search for prey
Can use chemical, mechanical, and visual stimuli, or can lure prey using deceptions
What are common stationary predators?
sea anemones and other cnidarians
What are common mobile predators
fishes, starfish, gastropods, birds, crabs
Optimal Foraging Theory
establishes rules used by predators to optimize their food intake, by max amount of energy gained or min amount of energy used searching
Diet-Breadth model
more prey, less choosy, lots of prey, select the best
Time in patch model
the time spent in a patch of prey should increase with an increase of travel time between patches
Typical marine organism predator avoidance
Crypsis, blending with the background, deceit, escape responses, mimicry
Crypsis
Blending with the background, a lot of fishes, crustaceans, and cephalopods employ chromatophores which are cells that can rapidly alter their color
Batesian mimics
may be harmless yet resemble a species that is dangerous
What marine organisms produce toxic compounds
acids by seaweeds or tunicates for example
what is an example of mutualism
hermit crabs that carry anemones on shells and claws // the crabs can use the stinging tentacles as a threat, and the anemone uses the shell as a substratum
What is another remarkable example of mutualism
Cleaner shrimp or fishes that pick ectoparasites off fishes, and have reduced predation
Ectoparasites
live attached to or embedded within gills, body walls, and other surfaces
Endoparasites
Live within the body and may occupy circulatory vessels or organs and tissues
