About the Data

Species records include data on invasions history, distribution, ecology, impact, and more. These data were gathered from published literature and targeted surveys. All records have undergone expert review, unless otherwise noted.

View details »

Species Profiles

NEMESIS includes detailed information on about 500 species of marine and estuarine of invertebrates and algae introduced to the United States. Each record contains information on taxonomy, distribution, ecology, and impacts, as well as references.

View details »

Daily Invader

Ciona savignyi

Ciona savignyi

Solitary Tunicate
Ciona savignyi appears to be native to Japan and possibly offshore waters of Alaska and British Columbia. Introduced populations were first reported on the West Coast of North America in 1985 at Long Beach Harbor, southern California. Since then it has been reported in a number of southern, central and northern California locations, including San Diego Bay, Santa Barbara Harbor, Monterrey, Moss Landing, San Francisco Bay, Tamales Bay, Bodega Harbor, and Humboldt Bay. In 1998 it was found in Puget Sound near Seattle, Washington, and there are reports of extensive populations in several areas of Puget Sound and the northern reaches of the San Juan Islands. It is abundant in harbors and marinas and was likely spread through hull fouling on commercial and recreational boats. Despite its abundance in the fouling community, very little is known about its impacts, but it might compete with C. intestinalis, however, die-offs of both species due to environmental changes make this difficult to assess.

Daily Invader for 2017-11-04

Image Credit Melissa Frey, Royal BC Museum, Canada
More information