Pogonophora
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PHYLUM POGONOPHORAQueency Joy Batucan
Darrienne Maureen Bernabe
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POGONOPHORA
Also, known as “Beard Worms”
Completely unknown until the
twentieth century
Tube-dwelling worms found throughout
world’s oceans (at depths between 100
and 4000 m)
All 120 described species are marine
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CHARACTERISTICS
Bilaterally symmetrical and vermiform.
Body has more than two cell layers, tissues and organs.
Body cavity is a true coelom. Body possesses no gut, mouth or
anus. Body possesses 3 separate sections, a
prosoma, a trunk and a opisthosoma.
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CHARACTERISTICS Has a simple nervous system with an
anterior nerve ring and a ventral nerve chord.
Has a true closed circulatory system. Has simple respiratory organs. Reproduction normally sexual and
gonochoristic. Feed on detritus, or dissolved nutrients,
or through symbiosis with bacteria. All live in marine environments.
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Defining Characteristics
No mouth or digestive tract Organ known as Trophosome filled
with chemoautotrophic mutualistic bacteria
Unsegmented except for rear portion of animal, (or opisthosoma).
Conspicuous red color at ends of plume due to hemoglobin
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Body Structure
Divided into four sections: The cephalic lobe The glandular region The trunk And the opisthosoma
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The Cephalic Lobe
Consists of a “plume” of one to many thousands of ciliated tentacles
Used for gas exchange, and some nutrient uptake
Also thought to be used to obtain Hydrogen Sulfide
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The Glandular Region Contains cells that
secrete chitinous tube Some species contain
“girdle”, (or vestimentum) in this region, which aids in keeping the worm steady in its tube
Normally stand upright and are buried, to about 50% of their length in the substrate
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The Trunk The longest part of the
pogonophoran body bears two rows of
papillae (little bumps or warts) along its length
2 regions of ciliation, and 2 girdles of setae (help the animal hold its place within its tube)
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The Opisthoma
5 to 30 segments This holdfast is thicker
than the trunk section and is buried in the substrate beyond the end of the animal’s tube.
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Modes of Nutrition
Since pogonophora lack a digestive tractmany speculations have been made as tohow they obtain nutrients:
Via tentacles› many believe that some of the smaller species
can obtain dissolved organic matter through their tentacles
Via chemoautotrophic bacteria› The tentacles absorb hydrogen sulfide and
transport it using hemoglobin to the trophosome where it is converted to carbohydrates by the many bacteria that live there
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Pogonophora: Phylum or Not?
According to many recent studies involving the sequencing of the elongation factor-1 alpha and developmental studies comparing larvae and basic body plans has grouped the Phylum Pogonophora within the Phylum Annelida.
Now known more accurately as Siboglinidae (a family of polychaete annelids)
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