Transcript Phylum Sipuncula

Phylum Sipuncula
Peanut Worms
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Phylum Sipuncula
Peanut Worms
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Defining
Characteristics
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Anterior part of
the body forms
an eversible and
fully retractable
proboscis with a
mouth at the end
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Multicellular
bodies (urns) in
the coelomic
fluid
Eversible proboscis
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Phylum Sipuncula
Sipunculan Body Plan
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Phylum Sipuncula
Peanut Worm Feeding
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Mucus covered tentacles trap organic material from the
surrounding water or sediment
During burrow formation sediment may be ingested directly
Mouth and anus are both located anteriorly resulting in a U
shaped gut
Phylum Sipuncula
Sipunculan
Anatomy
Circulatory System
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Unlike the annelids
sipunculans lack a
circulatory system with
a heart and blood
vessels
Excretion occurs via
urns
– Cells that float in
the coelom
collecting waste
products bringing
them to nephridia
Phylum Sipuncula
Reproduction
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Sexes are separate and
fertilization occurs in the sea
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Trochophore larvae forms
resembling Annelida and Mollusca
larvae
Some species have a
trochophore that further
develops into a
pelagosphera
Phylum Sipuncula
Local Species
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Hermit Sipunculan (Phascolion strombus)
– Lives in the shells of gastropods
Rock-Boring Sipunculan (Themiste alutacea)
– Associated with calcareous surfaces (coral and limestone)
Burrowing Sipunculan (Sipunculus nudus)
– Burrows in fine and coarse sands
Phylum Sipuncula