Biological Invasions

, Volume 11, Issue 10, pp 2181–2194 | Cite as

Population dynamics and life cycle of the introduced ascidian Microcosmus squamiger in the Mediterranean Sea

Original Paper


Marine introductions are a serious threat for biodiversity, especially in seas where shipping is intensive. Microcosmus squamiger is a widespread marine invader that can alter native biota and it is therefore imperative to understand its biology and ecology. We studied the population dynamics and reproductive cycles of M. squamiger over a 2-year period, as well as its settlement and colonization patterns, in a north-western Mediterranean (NE Spain) locality where M. squamiger has been introduced. All biological parameters showed a strong seasonal pattern that peaked in summer with a major spawning episode at the end of summer. Size-frequency histograms indicated a 2-year cycle. Colonization experiments suggested that M. squamiger recruitment mortality is high and requires a well structured community. In addition, we monitored the abundance of the native predator Thais haemastoma, which showed a significant positive correlation with M. squamiger biomass, indicating its potential usefulness as a biological control.


Invasive species Population dynamics Life cycle Microcosmus squamiger Gonad index Biological control 


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Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  1. 1.Departament de Biologia Animal (Invertebrats), Facultat de BiologiaUniversitat de BarcelonaBarcelonaSpain
  2. 2.Centre d’Estudis Avançats de Blanes (CEAB, CSIC)Blanes (Girona)Spain

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