Download presentation
Presentation is loading. Please wait.
Published byMyrtle Moody Modified over 9 years ago
1
3 Ecological and Evolutionary Principles Notes for Marine Biology: Function, Biodiversity, Ecology by Jeffrey S. Levinton
2
Ecological hierarchy Population-level processes Individual interactions
3
The Ecological Hierarchy Biosphere Ecosystem Community Population Individual
4
Ecological Processes - Population Level Competition Predation Parasitism Disturbance Facilitation Larval dispersal (unique to ocean)
5
Interactions Between Individuals +- Territoriality +- Predation + - Parasitism ++ Mutualism + 0 Commensalism
6
POPULATION EFFECTS - prey population collapse, occasional predator-prey cycles Predation effects reduced when (a) Prey population has rapid recovery rate (b) Predators limited by other factors (e.g., octopus by den sites) (c) Escapes from predation: (1) escape behavior, (2) cryptic color, form, (3) chemical (warning coloration) or mechanical defense (fixed or inducible), (4) refuge habitat, (5) refuge time (nocturnal, feeding at time of low tide when predators are away) Predation
7
Predation Example: Stationary Predator Anthopleura xanthogrammica
8
Mobile predators
9
Crypsis : Decorator crab flatfish
10
Thaumoctopus mimicus mimic octopus http://video.google.com/videosearchq=mimic+octopus&hl=en&e mb=0&aq=f# Instructor: here is a recommended link to use for class
11
Pseudoceros bifurcus (flatworm in Phillipines) has tetrodotoxin (blocks Na channel) Aposematic (warning coloration) http://www.rzuser.uni-heidelberg.de/~bu6/flat0415.jpg Instructor: here is a recommended link to use for class
12
Escape Behavior Scallop Lima hians Spisula escaping starfish
13
Inducible defenses bryozoan spines - nudibranch. +predator - predator Barnacle Chthamalus anisopoma Why just a plastic response?
14
Optimal Predator Models Diet breadth - rule: food scarce, increase breadth Time spent in a patch - rule: greater the distance between patches, spend more time in a given patch Size selection - maximize energy intake, usually leads to selection for intermediate size
15
Energy reward of a mussel as function of size Preference of crab for different mussel sizes Shore crab Carcinus maenas feeding upon the mussel Mytilus edulis. Optimal Prey Size: Maximize intake - Function of time and prey size
16
Parasitism Parasites evolve to reduce damage to host Commonly involve complex life cycles with more than one host Parasites may invade specific tissues, such as reproductive tissue of the host
17
Complex life cycle found in a trematode parasite living in several marine animal hosts
18
Invasion of the parasitic rhizocephalan barnacle Sacculina into the body of a crab Planktonic larva of parasitic barnacle (attaches to 1st antenna of crab
19
Mutualism: Cleaner wrasse removes ectoparasites from a number of species of fish that visit localized “cleaning stations” on a coral reef. Fish (b) is a mimic species that actually attacks fish that would normally be a “client” of the cleaner wrasse.
20
Commensalism Commensal crab and fish live in this burrow of Urechis caupo
21
Effects of Disease Destruction of important species, e.g., shellfish disease attacks Removal of ecologically important species (example: removal of key grazer) Interaction with other factors such as climate change
22
Construction of a Population Model dN/dT = f (N,M,R,I,E) N = population size M = mortality R = reproduction I = immigration E = emigration M is a function of physical environment, competition, predation, etc. R function of physical environment, resources (e.g., food)
23
Example of Population Model Barnacles: What parameters matter the most? dN/dT = f (N, I, M) I is larval settlement M a function of larval-adult interactions, overgrowth, predation Note R doesn't matter if planktonic larvae mainly go elsewhere
24
Mortality pattern expected for a species with a planktonic larva. Note higher mortality rate of larval stage.
25
Modes of Population Change Exponential Growth Logistic growthRandom change
26
Small-scale Spatial Distribution of Individuals Random Uniform Aggregated…
27
Metapopulation Definition: A group of interconnected subpopulations Sources and Sinks Aggregations on larger scales….
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.