benthic communities living along the bottom of the ocean
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Benthic Communities
living along the
bottom of the ocean
Benthic Communities
living along the
bottom of the ocean
Benthic Communities
• Rocky Intertidal Zones
• Coral Reefs
Rocky Intertidal Zones
Rocky Intertidal ZonesHard places to live
• Drying out during low tide– Close shells, move to moist areas
• Wave Shock– Have holdfasts, cement, tube feet
• Lack of space to hold on– competition
• Rapid changes in temperature & salinity– Close shells or be able to withstand it
Table 15.1
Coral Reefs
• Corals– Are animals (Cnidarians)– Small (ant-sized) polyps live in large colonies– Hermatypic corals secret a calcium carbonate
skeleton…the reef
Coral Reefs
• Zooxanthellae– Dinoflagellate that lives within the coral polyp– A mutualism– Algae provide food, speeds up calcium
carbonate deposition & get nutrients in return
Coral Reefs
• Hermatypic Coral’s ideal habitat is 5-10 m (16-33 ft) depth & temperatures warmer than 18-21oC (64-70oF)
Fig. 14-12, p. 294
Coral Reefs
• Reefs support a large diversity of other organisms– Home to 25% of the world’s marine species
Symbiosis
• the co-occurrence of two species in which the life of one is closely tied with the life of another
Symbiosis
• Three types– mutualism (++)
• Anemone fish, cleaner shrimp or wrasse, zooxanthellae
– commensalism (+0)• pea crabs, remoras & shark, whale barnacles
– parasitism (+-)• isopods, roundworms, etc.
Figure 14.15b
Figure 10 p.221
Figure 14.15a
Figure 14.15c
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