Rocky Shores and Tide Pools Flashcards
Intertidal upper limit
Defined by temperature and desiccation
Intertidal lower limit
Defined by biological interactions
Species found in the upper intertidal
- Species of lichen and encrusting algae
- Exposed to the driest conditions (high tide reach)
- No invertebrates present
Spray zone
The area above the upper intertidal that is barely touched by water
Species found in the middle intertidal
- Barnacles
- Rockweeds (brown algae)
- Blue mussels
Species found in the lower intertidal and tide pools
- Irish moss
- Sea anemones and sea stars
- Chitons
- Sea urchins
- Dog whelks and crabs
- Sculpin
What are the two main differences between intertidal zonation in the Atlantic and Pacific?
Atlantic Ocean: HT lichens dominate, LT Irish moss dominate
Pacific Ocean: HT periwinkles dominate, LT various sea weeds dominate (no Irish moss)
List the adaptations and responses to wave action
- Development of holdfasts (seaweeds)
- Development of glue, cement, or byssal threads to attach to rocks (mussels and barnacles)
- Development of a strong, muscular foot (chiton, snails)
- Development of tube feet with ampulla for attachment (sea stars and sea urchins)
- Shape
- Shell thickness
- Flexibility
- Large numbers
Holdfasts
An adaptation developed by seaweed to prevent waves from moving them
Byssal Threads (and glue, cement)
An adaptation to wave action; developed to permanently attach to rocks
- Mussels and barnacles
Shape adaptation to wave action
Animals living in exposed shores are shorter or thicker
Animals in calm conditions are taller and thinner
Shell thickness adaptation to wave action
Shells are thicker in rough conditions
List the responses/adaptations to temperature & salinity changes
- Preference for crevices
- Sealing off the shell with Operculum
- Aggregation in large densities
- Shells have ridges for heat loss
- Reduction of movement
Dominant competitor
Species that monopolize the use of space
Keystone predators
Species that keep in check the dominant competitor
