| 1. |
- Hansson, Lars Johan, et al.
(författare)
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Massive recruitment of the barnacle Semibalanus balanoides in the Clyde Sea (Scotland, UK) in the spring of 2000
- 2003
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Ingår i: Journal of the Marine Biological Association of the United Kingdom. - 0025-3154. ; 83:5, s. 923-924
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Tidskriftsartikel (refereegranskat)abstract
- In April 2000 a massive recruitment of the barnacle Semibalanus balanoides was observed in the Clyde Sea. At one location 700 cyprids l(-1) of this species were recorded. This is similar to3500 times more abundant than previously recorded, and resulted in metamorphosis of some cyprids whilst still in the plankton, as well as massive settlement, with recruits found on adults and in the splash zone. The maximum density recorded was 109 settlers cm(-2). Over the next 60 d mortality averaged 85%, resulting in a mean density of 8.4 recruits cm(-2) in June 2000. Recruitment varied spatially at the kin and in scale (site, shore height) but there was no evidence that it was affected by the presence of adult conspecifics.
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| 2. |
- Head, R. M., et al.
(författare)
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Gregarious settlement in cypris larvae: The effects of cyprid age and assay duration
- 2004
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Ingår i: Biofouling. - : Informa UK Limited. - 0892-7014 .- 1029-2454. ; 20:2, s. 123-128
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Tidskriftsartikel (refereegranskat)abstract
- Gregarious behaviour of marine larvae is perhaps most clearly associated with finding a suitable habitat in a changeable or restricted environment, or with finding other conspecifics with which to mate. Prior work has shown that in settlement assays using cypris larvae of the barnacle Balanus amphitrite , gregarious interactions significantly affected the interpretation of experiments testing the activity of organic settlement promoters and inhibitors. Other studies have also shown effects of cyprid age and pheromone concentration on settlement behaviour. However, the effects of interactions between gregariousness and these two factors are not known. The aim of this study was to test the hypotheses that i) as cyprids age the effects of gregariousness become less apparent, and ii) as the duration of the experiment increases gregarious effects become more apparent, using cypris larvae of B. amphitrite and Balanus improvisus . Three age classes of cyprids were used at six densities in a fully factorial design. For B. improvisus cyprids significant gregarious effects occurred between 3 or more larvae, and although larval age and experiment duration had significant main effects, there were no interactions between these important factors and gregariousness. For B. amphitrite cyprids significant gregarious effects also occurred with greater than or equal to3 larvae per well, though this effect was strongly dependent upon experiment duration. B. amphitrite cyprid sensitivity to conspecific cues does not change with age, although increasing experiment duration and age interact to increase settlement. Differences between species may be due to different thresholds to conspecific larval cues, or B. improvisus cyprids release much more larval temporary adhesive during exploration.
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