It can be confused with the southern cup coral (Astrangia solitaria), but that species has a more southerly distribution, is generally brown, may be solitary, has larger corallites 4 mm (0.16 in) wide with 36 septa (stony ridges), [6] and does not contain zooxanthellae.

[7] Astrangia poculata is native to the western Atlantic Ocean and Caribbean Sea where its range extends from Cape Cod in Massachusetts to the Gulf of Mexico.

The embryos hatch into planula larvae which drift with the plankton before settling to the seabed and undergoing metamorphosis into polyps.

[9] The polyps spread their tentacles to feed, gathering plankton and other food particles from the water passing by.

In colder conditions it may stop growing and the coenosarc (soft tissues) may die back to some extent [10] or lose symbionts via expulsion,[11] rendering the stony skeleton prone to being fouled by other organisms [6] and undergoing a winter quiescence.