1. Phylum Sipuncula 1 Peanut Worms

2. Phylum Sipuncula 2 Peanut Worms Defining Characteristics – Anterior part of the body forms an eversible and fully retractable proboscis with a mouth at the end Eversible proboscis – Multicellular bodies (urns) in the coelomic fluid

3. Phylum Sipuncula 3 Sipunculan Body Plan

4. Phylum Sipuncula 4 Peanut Worm Feeding 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

5. Sipunculan Anatomy

6. Phylum Sipuncula 6 Circulatory System 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

7. Phylum Sipuncula 7 Reproduction Sexes are separate and fertilization occurs in the sea – Trochophore larvae forms resembling Annelida and Mollusca larvae Some species have a trochophore that further develops into a pelagosphera

8. Phylum Sipuncula 8 Local Species – 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