From the Pacific Ocean to the Mediterranean Sea: Watersipora arcuata, a new non-indigenous bryozoan in Europe

Abstract

This study reports the first record of the cheilostome bryozoan Watersipora arcuata in the Mediterranean Sea, namely in a marina of the Ligurian Sea (Italy), during two monitoring surveys carried out in 2013 and 2014, representing to date the first European finding. The species, whose native origin is deemed to be the Tropical Eastern Pacific region, was already reported as being introduced to California, Australia, New Zealand and Hawaii, but not outside the Pacific Ocean. The genus Watersipora includes 13 species of encrusting bryozoans, difficult to distinguish using simple visual clues and usually requiring careful morphological measurements, with appropriate microscopy methods. A detailed taxonomic description of W. arcuata is provided here, in comparison with the similar species W. nigra and W. platypora.

Key words:

• Non-indigenous species
• recreational boating
• watersiporids
• zooid morphometrics

Acknowledgements

The authors gratefully acknowledge Mr Sylvain Pont of the Natural History Museum of Paris, Service of Scanning Electron Microscopy and the Direction of Collections, UPSEM-EDS for the SEM images; Martina Marić, Anja Nikolova for their support during the 2014 sampling survey, and Aylin Ulman for the English revision of the text; and the Capitaneria di Porto and Demanio Marittimo of Santa Margherita Ligure (Comune Santa Margherita Ligure) for the authorization to carry out surveys. The manuscript greatly benefited from the comments of Leandro M. Vieira and another, anonymous reviewer.

Disclosure statement

No potential conflict of interest was reported by the authors.

Editorial responsibility: David Thieltges

Additional information

Funding

This work was supported by the European Union’s Seventh Framework Programme for research, technological development and demonstration (FP7/2007-2013) within the Ocean of Tomorrow call under Grant Agreement No. 266445 for the project Vectors of Change in Oceans and Seas Marine Life, Impact on Economic Sectors (VECTORS); Jasmine Ferrario was supported by a PhD grant from the University of Pavia.