Download Phylum annelida marine worms

Marine Annelids: Class Polychaetes
(Marine Worms)
• Almost all marine annelids are polychaetes
(class Polychaeta) are bilaterally symmetric,
which are also known as “bristle worms”
which is due to the translation from the
Greek word polychaeta = with much hair.
These bristles have many purposes, and
branch out of their legs
(referred to as parapodia).
Home and Feeding
• Many polychaetes live in temporary or permanent tubes
– Singular
– aggregations (groups)
• Can be carnivorous or chemosynthetic
organisms.
• Tube-dwelling polychaetes can be
are
suspension feeders, trap and capture
free floating scraps of food or plankton.
• They use their “bristles” for capturing
food and for gathering oxygen
Most extreme worm on Earth!
• One of the most remarkable polychates is the Pompeii worm
• Found only at hydrothermal vents in the Pacific Ocean *Great
example of a symbiotic relationship resulting in
chemosynthesis (making food out of only chemicals like sulfur,
nitrogen, carbon)
– Temperatures as high as 80°C (176°F)!
– “Fleece-like” covering of bacteria on their backs; the
worms secrete mucus to feed the bacteria and in return,
are protected by a degree of insulation on their backs
Polychaetes are usually colorful!
Christmas Tree Worm
Free-living polychaete
Advanced Life Forms!
• Polychaetes have organs that sponges and
cnidarians DON’T have such as: brain, hearts
(yes plural), blood vessels, kidneys and an
anus.
• Each segment
Can break off and
Form a new worm!
Marine worm reproduction
- When ready to reproduce, they go through a
process called epitoky which is the
development of their gonads which become
separated from the body of the worm and are
called epitokes. When this happens,
fertilization occurs externally.
- Can be asexual by process similar to budding
of jellyfish in which a small segment buds off
and floats with other plankton, feeding and
adding new layers are on their own.
Interesting Facts
• Some worms are not satisfied with plankton in
their diet, so they resort to producing an acid
which can decompose bones of fish and
whales. The female worms are the only ones
that do this, the males are microscopic and
live within the female.
• Then there’s Bobbit worms which can reach
heights up to 10 feet.
• https://www.youtube.com/watch?v=3H4J5QD
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