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Pennatulid Bed (Biotic Group)

Component: Biotic

Unique Identifier: 537

Biotic Setting Benthic/Attached Biota
Biotic Class Faunal Bed
Biotic Subclass Soft Sediment Fauna
Biotic Group Pennatulid Bed
Biotic Community Halipteris Bed
Pennatula Bed
Stylatula Bed
Renilla Bed

Definition Subtidal soft-bottom habitats that are dominated by sea pens or sea pansies (Phylum Cnidaria, Order Pennatulacea). These are colonial octocorals with a central stem-like support attached to a root-like peduncle, adapted for life in soft sediments. An arrangement of suspension-feeding polyps in a single plane on two sides of the central stem (which is a specialized polyp) gives some sea pens the overall appearance of a feather or quill pen. The root-like peduncle is embedded in soft sediments, but the sea pen can move to a new area if conditions are unfavorable. Sea pansies are more compact and fleshier than sea pens. Pennatulids are often common in deeper waters.