Possible introduction of marine species by long distance drift: an example with a crustacean from USA to France.

International audienceOnce upon a time, it happened that a buoy located on the USA coast between Florida and Georgia (30-59-39.562 N, 081-24-27.669 W according to US coast guards) broke its attaches and started a long journey across the Atlantic Ocean from April 2005 onwards. This buoy drifted for about 18 month and finally reached the French offshore zone near Concarneau Bay, Brittany, on October 2006.The immerged part of the buoy was covered with a variety of organisms. Samples were collected and sent to the Muséum national d'Histoire naturelle - Paris, for identification.Three species of Crustacea were identified. The first two are classical hosts of floating objects, that are sea turtles or ship hulls viz the common gooseneck barnacle, Lepas anatifera Linnaeus , 1758 [abundant, mean length of capitulum ca. 30-32 mm, peduncle length ca. 40-55 mm] and Columbus or Flotsam Crab Planes minutus (Linnaeus, 1758) [two large specimens: a brownish male of 28 x 26 mm and a reddish female of 23 x 22 mm in carapace width x carapace length].Surprisingly, a Florida stone crab, Menippe mercenaria (Say, 1818) was also present. This was a female of 54 x 38 mm, presenting the reddish brown typical coloration of the species, including the carapace and claws tan tomedium gray, with small dark spots, while legs are dark brown with distinct white bands. This finding indicates that intercontinental drift of floating objects can bring living specimens on shores that are far away from their native place, and contribute to the dissemination of organisms, and possibly (?) the introduction of species