| Sponge | ||||||
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| Taxonomic classification | ||||||
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| Included groups | ||||||
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Calcarea | ||||||
| Excluded groups | ||||||
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Crown radiata | ||||||
Sponges (Phylum: Porifera) are asymmetric, multi-celled animals. They are sessile and aquatic, and lack nervous, digestive or circulatory systems. [1] There is evidence in the literature to suggest that animals may have evolved a nervous system twice. [2]
{{Animalia}}
References
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