AEI Aquaculture Environment Interactions Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AEI 3:197-211 (2013) - DOI: https://doi.org/10.3354/aei00063 Reproductive seasonality of the invasive ascidian Didemnum vexillum in New Zealand and implications for shellfish aquaculture Lauren M. Fletcher1,2,*, Barrie M. Forrest1, Javier Atalah1, James J. Bell2 1Cawthron Institute, Private Bag 2, Nelson 7010, New Zealand 2School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand *Email: lauren.fletcher@cawthron.org.nz ABSTRACT: The global spread of invasive fouling species poses a significant barrier to the development of shellfish aquaculture, which has led to a need to understand the biological characteristics of fouling species that underpin management. One such fouling species, the colonial ascidian Didemnum vexillum, has become a very successful invader in temperate marine communities worldwide, and is proving problematic in a number of aquaculture regions. To evaluate the scope for managing risks to shellfish aquaculture around seasonal reproductive patterns, we assessed recruitment and larval development of D. vexillum in relation to water temperature, over a 20 mo period at 2 locations in central New Zealand. Our findings indicate that the reproductive season for D. vexillum in New Zealand is considerably longer than comparable northern-hemisphere populations (at least 9 mo of the year compared with 3 to 5 mo in the USA). Reproductive patterns were strongly correlated with water temperature, with a 3 mo period during the winter months (surface water temperature <12°C) when larval recruitment was not detected at our study sites. However, during that period, late-stage larvae were often present in tissue sections, suggesting that the species has the potential to recruit year-round, albeit at very low levels during winter. Information on the duration of the reproductive season as well as critical temperature thresholds for spawning will enable more effective risk management in relation to aquaculture industry practices (e.g. timing of seed-stock deployment), as well as assist in the wider management of this species. KEY WORDS: Biofouling · Non-indigenous species · Reproductive patterns · Temporal variation · Larval settlement · Recruitment · Tunicate · New Zealand Full text in pdf format PreviousNextCite this article as: Fletcher LM, Forrest BM, Atalah J, Bell JJ (2013) Reproductive seasonality of the invasive ascidian Didemnum vexillum in New Zealand and implications for shellfish aquaculture. Aquacult Environ Interact 3:197-211. https://doi.org/10.3354/aei00063 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AEI Vol. 3, No. 3. Online publication date: April 10, 2013 Print ISSN: 1869-215X; Online ISSN: 1869-7534 Copyright © 2013 Inter-Research.