title: The recently introduced bivalve Xenostrobus securis has higher thermal and salinity tolerance than the native Brachidontes variabilis and established Mytilopsis sallei.
abstract: The recently introduced bivalve Xenostrobus securis and the previously introduced Mytilopsis sallei (~30years) are dominant over the native Brachidontes variabilis in estuarine fouling communities in Hong Kong. This study tested whether these introduced species have higher thermal and salinity tolerance than the native species under local subtropical seawater conditions. Survival, attachment, clearance rate and byssal thread production of these three species were examined through 96-h acute temperature and salinity tests. The results indicated that X. securis responded normally over a wide range of temperature and salinity conditions. Though M. sallei exhibited a wide salinity tolerance, its sub-lethal responses decreased in cold-seawater conditions. Brachidontes variabilis had the narrowest tolerance to temperature and salinity. These findings may explain the dominance of the non-native bivalves over B. variabilis. The high tolerance of X. securis enables them to become highly invasive in subtropical regions across Southeast Asia, impacting natural communities and shellfish farming.
authors.affiliation: The Swire Institute of Marine Science, Faculty of Science, The University of Hong Kong, Cape d'Aguilar Road, Shek O, Hong Kong, China; School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China. Electronic address: jcarlos@connect.hku.hk.
authors.forename: Juan C
authors.initials: JC
authors.lastname: Astudillo
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Bonebrake
authors.affiliation: The Swire Institute of Marine Science, Faculty of Science, The University of Hong Kong, Cape d'Aguilar Road, Shek O, Hong Kong, China; School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China; State Key Laboratory in Marine Pollution, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China; Simon F.S. Li Marine Science Laboratory, School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
authors.forename: Kenneth M Y
authors.initials: KMY
authors.lastname: Leung
mesh_terms: D000818:Animals; D006723:Hong Kong; D058865:Introduced Species; D049879:Mytilidae / Q000502:physiology*; D054712:Salinity; D055049:Salt Tolerance; D012623:Seawater; D013696:Temperature
keywords: Brachidontes variabilis; Mytilopsis sallei; Non-native species; Salinity; Temperature; Xenostrobus securis