Establishment of the green mussel, Perna viridis (Linnaeus 1758) (Mollusca: Mytilidae) on the west coast of Florida

In 1999, the green mussel, Perna viridis, was first observed in Tampa Bay, Florida. This was the first reported occurrence of this Indo-Pacific marine bivalve in North America. The mussels found in Tampa Bay were confirmed to be P. viridis based on both morphological and genetic characteristics. Sin ce the initial discovery, surveys in Tampa Bay and on the west coast of Flo rida have documented the growth, recruitment, and range expansion of P. vir idis. From November 1999 to July 2000, the mean shell length of a Tampa Bay population increased from 49.0 min to 94.1 mm, an increase of 97%. Populat ions of P. viridis are successfully reproducing in Tampa Bay. Recruitment w as observed on sampling plates in May and continued through July 2000. The full extent of mussel colonization is not clear, but mussels were found out side Tampa Bay in St. Petersburg, Florida, south to Venice. Based on these studies it is evident that P. viridis has successfully invaded Tampa Bay an d the west coast of Florida, The long-term impact of P. viridis on native c ommunities off the west coast of Florida cannot be predicted at this time.