|Temperature dependent larval occurrence and spat settlement of the invasive brackish water bivalve Mytilopsis leucophaeata (Conrad, 1831) (Dreissenidae)|van der Gaag, M.; van der Velde, G.; Wijnhoven, S.; Rajagopal, S. (2014). Temperature dependent larval occurrence and spat settlement of the invasive brackish water bivalve Mytilopsis leucophaeata (Conrad, 1831) (Dreissenidae). J. Sea Res. 87: 30-34. dx.doi.org/10.1016/j.seares.2013.11.014
In: Journal of Sea Research. Elsevier/Netherlands Institute for Sea Research: Amsterdam; Den Burg. ISSN 1385-1101, more
Population dynamics; Larvae; Settlement; Biofouling
|Authors|| || Top |
- van der Gaag, M.
- van der Velde, G.
- Wijnhoven, S., more
- Rajagopal, S.
Mytilopsis leucophaeata, an invasive bivalve species, causes fouling problems by settling on submerged constructions and in cooling water circuits in brackish water. To predict spat fall we studied the larval occurrence and settlement of this species in the brackish Noordzeekanaal canal in the Netherlands for several years (1989-1992), while measuring water temperature, salinity and chlorophyll a levels. Larvae were collected monthly by means of a plankton net drawn across the whole width of the canal. Settled spat were collected from PVC panels exposed for one month. Larvae first appeared in May or June, and reached maximum numbers in June or July, before disappearing in October, November or even December. The larval period started at a water temperature of 14 degrees C, reached maximum numbers at 19-23 degrees C and ended when it fell below 9 degrees C. No larvae were observed any-more until the temperature rose to 14 degrees C in the spring of the next year. Spat fall (June-November) was related to the water temperature in April. If the water temperature in April was lower than 12.5 degrees C, spat fall started in July, while if temperature was already higher in April, it started a month earlier. The spat fall period started at 15 degrees C, with maximum numbers at 20-24 degrees C, and ended when the water temperature dropped below 5 degrees C. Redundancy analysis (RDA) demonstrated a strong relationship between larval and spat densities and water temperature.