Page 147 - (DK) Ocean - The Definitive Visual Guide
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SEA-BED STABILIZERS
This sea bed owes its luxuriant
growth, including hydroids, soft
corals, and brittlestars, to the
many Flame Shells and Horse
Mussels hidden under the surface.
These molluscs bind the shifting
sediments with strong threads,
creating a stable, complex surface
that many other animals can
colonize. Flame Shell nests join
together to form extensive reefs,
with holes for water exchange,
so many other organisms can live
inside and beneath the nests.
DISCOVERY
SEA WRECKS
The complex shape and hard surfaces Beneath the Surface SEDENTARY HABIT
of shipwrecks such as the one This Norway Lobster
shown here (the Eagle, off Florida) Wave-disturbed sand and gravel creates a mobile, lives in a U-shaped
attract sedentary invertebrates and well-oxygenated environment. Animals that live here, burrow with two
fish. A new wreck may take some exits and is mainly
time to become colonized, such as crustaceans, and echinoderms, move through nocturnal.
depending on the material from the shifting sand without building permanent homes.
which it is made. Small hydroids, Animals that disturb sediments in this way, or by
barnacles, and keelworms often ingesting and defaecating it, are called bioturbators and are important OCEAN ENVIRONMENTS
settle first, paving the way for recyclers of nutrients. Less-disturbed sediments are inhabited by sediment
other animals and seaweeds to stabilizers. These sedentary animals, many living in permanent burrows
grow on their hard shells. Filter or tubes, can cope with oxygen depletion and being covered over. Some
feeders thrive in enhanced currents
on the super-structure, while the strengthen their burrows by lining them with substances such as
spaces inside offer hiding places mucus and draw in seawater to supply food and oxygen. Others filter
for fish and octopuses. seawater or hoover sediment by extending their siphons to the surface.
Microscopic creatures (the meiofauna) live in between the sand grains.
