Answer:

polyps

Answer	Crossword Clue
POLYPS	Sea anemones et al.
POLYPS	Corals, e.g.
POLYPS	Coral secreters

POLYPS	Sea anemones, e.g.
POLYPS	Hydras, sea anemones, et al.
POLYPS	Hydras, e.g.
POLYPS	Corals, sea anemones, etc.
POLYPS	Sea anemones, for example.
POLYPS	Sea Anemones.
POLYPS	Sea creatures.
POLYPS	Marine life.

POLYPS	Subjects of Benchley's sex study
POLYPS	Sea anemones
POLYPS	Reef-builders
POLYPS	Hydras
POLYPS	Coral creatures
POLYPS	Growths that may be removed by surgery
POLYPS	Sea fan colonists
POLYPS	Coral colonists

POLYPS	Medusas' counterparts
POLYPS	Sea anemones and coral, e.g.
POLYPS	Tentacled sea creatures
POLYPS	Hydra and coral
POLYPS	Tentacled creatures