Styela plicata

History of Spread

The origin of Styela plicata (Pleated Sea-Squirt) is unknown. The type specimen was described from a ship in the Delaware River, Philadelphia PA, in 1823 (Van Name 1912). It was apparently established south of Cape Hatteras by the late 19th century, when regular collecting began. Styela plicata is now found on warm-temperate to tropical coasts around the world. It is believed to have been introduced to the Mediterranean, probably centuries ago (C. F. Monniot, in Fischer et al. 2000). James T. Carlton considers the species introduced to the northwest Atlantic, perhaps from the Indo-Pacific, based on the general diversity of this genus in the Pacfic (Carlton and Ruckleshaus 1997; Carlton, pers. comm.). However, this species is largely absent from the Indo-Pacfic, and is apparently introduced to Australia (Kott 1985). It is widespread in the Northwest Pacfic, one possible region of origin (Nishikawa 1991).

In the Northeast Pacific, S. plicata was first collected in San Diego Bay in 1916, and ranges north to Santa Barbara CA (Lambert and Lambert 1998). ). Since 2000, it has been found on SERC fouling plates in San Francisco Bay, where it is apparently now established (Ruiz et al., unpublished data)

In the Northwest Atlantic, S. plicata was described by LeSeur in 1823, from a specimen (presumably dead) found on a ship of unreported origin in Philadelphia, on the fresh Delaware River (Van Name 1912). Specimens were collected by dredge off the Gulf Coast of FL in 1877, from the coast of SC in 1880, and from Bermuda in 1882 (U.S. National Museum of Natural History 2002). This tunicate ranges north to Cape Hatteras, and through the Gulf of Mexico and Caribbean (U.S. National Museum of Natural History 2002).

An unidentified specimen of 'Styela sp.' was reported from Lynnhaven Inlet, and Little Creek, Virginia Beach VA (Ferguson and Jones 1949). In 2002, S. plicata was common in some locations around Norfolk and Virginia Beach VA (Ruiz et al., unpublished data). Identifications were confirmed by Gretchen Lambert.

References- Carlton and Ruckleshaus 1997; Ferguson and Jones 1949; Fischer et al. 2000; Kott 1985; Lambert and Lambert 1998; Nishikawa 1991; U.S. National Museum of Natural History 2002; Van Name 1912

Invasion Comments