communities of rocky shores
TRANSCRIPT
© 2011 Pearson Education, Inc.
Communities on Rocky ShoresEpifauna
Attached to substrate (e.g., marine algae)
Move over seafloor (e.g., crabs, snails)
Moderate diversity of speciesGreatest animal diversity at
tropical latitudesGreatest algae diversity at mid-
latitudes
© 2011 Pearson Education, Inc.
I. Intertidal Zonation (Spray Zone & Tidal Zones)Rocky shore:
Spray zone – above spring tide zone
Intertidal zone High tide zoneMiddle tide zoneLow tide zone
© 2011 Pearson Education, Inc.
a) Spray Zone Supratidal zone
Organisms
Avoid drying out
Many animals have shells
Few species of marine algae
© 2011 Pearson Education, Inc.
b) Intertidal Zone Organisms (Tidal Zones)
1. High tide zoneAnimals have shells to
avoid drying outMarine algae—rock
weeds with thick cell walls
© 2011 Pearson Education, Inc.
Intertidal Zone Organisms2. Middle tide zone
More types of marine algae
Soft-bodied animals (Barnacles)
© 2011 Pearson Education, Inc.
Intertidal Zone Organisms3. Low tide zone
Abundant algaeMany animals
hidden by sea weed and sea grass
Crabs abundant in all intertidal zones
© 2011 Pearson Education, Inc.
2. Sandy Beach Organisms and Adaptations
Burrowing animals
No stable, fixed surface
Burrowing provides more stable environmentLess risk of
temperature extremes and drying out
© 2011 Pearson Education, Inc.
Sandy Beach Organisms and Adaptations
Bivalve mollusksSoft body, hard shellExample: clams
and musselsGreatest number in
low tide regions
© 2011 Pearson Education, Inc.
Sandy Beach Organisms and Adaptations
CrustaceansSegmented body,
hard exoskeleton, paired jointed limbs
Example: crabs, lobsters
© 2011 Pearson Education, Inc.
Sandy Beach Organisms and Adaptations
EchinodermsSpiny skinFive tapered
legsExample:
starfish and heart urchin
© 2011 Pearson Education, Inc.
3. Mud FlatsEelgrass and turtle
grass common
Bivalves and other mollusks
Fiddler crabs
© 2011 Pearson Education, Inc.
4. Shallow Offshore Ocean Floor Communities
Rocky bottoms (subtidal)
Kelp and kelp forests Attaches to rocky
bottoms Can grow up to 0.6
meters (2 feet) per day
Productive ecosystems
Provides shelter for other organisms
© 2011 Pearson Education, Inc.
Kelp Distribution
© 2011 Pearson Education, Inc.
5. Rocky Bottom Shallow Offshore Ocean Floor Communities
LobstersLarge, spiny
antennaeLive in water deeper
than 20 meters (65 feet)
ScavengersAlso feed on live
animals
© 2011 Pearson Education, Inc.
Rocky Bottom Shallow Offshore Ocean Floor Communities
OystersSessile bivalve
mollusksThick shellStart life as
plankton