The ability to recognize individuals and track growth over time is crucial to population dynamics research as well as studies of animal behavior. Invertebrates are particularly difficult to track as they often molt, have regenerative capabilities, or lack hard parts to attach markers. We tested, in laboratory and field studies, a new way of marking sea anemones (order Actiniaria) by injection of three vital stains (i.e., neutral red, methylene blue, and fluorescein). Neutral red and methylene blue did not affect growth or survival, but fluorescein was lethal at high concentrations.

Many studies have reported the arrival and subsequent range expansion of foreign species within the marine ecosystems, but few studies have documented species that arrive and fail to establish. In 2000, the sea anemone Sagartia elegans (Dalyell, 1848) was first found in Salem, MA and persisted seasonally until the winter of 2010-2011 after which it has not been found. In both laboratory and field based temperature growth studies, S.