- Marine Science Laboratories, Menai Bridge, Anglesey
- Department of Zoology, University of Glasgow, Glasgow, UK
1. A study has been made of the sublittoral settlement and growth of Balanus balanoides and Balanus crenatus at Greenock and Mallaig, and of Elminius modestus at Rosyth. Data were collected from tufnol panels immersed for one, two, and three month periods during March 1961 to July 1963. 2. All three species grew rapidly during the first month after metamorphosis. B. crenatus had the highest growth rate, followed by E. modestus and B. balanoides. The size and growth rate of B. balanoides and B. crenatus were greater at Greenock than Mallaig. Growth showed down in all species during the second month; this was related to crowding. 3. At Greenock, B. crenatus and B. balanoides showed two peaks of settlement. 4. B. balanoides suffered a heavy mortality after metamorphosis, E. modestus less, and B. crenatus least of all. 5. The presence of many older barnacles induced some cyprids to leave a surface without metamorphosing; those that did stay, spent less time between attachment and metamorphosis. 6. On the panels immersed for one month, there was no obvious evidence that cyprids specifically recognised spat of their own species. On the one month panels, spat were uniformly distributed (spaced out), and there may have been an inverse relationship between the numbers of cyprids and spat. 7. Cyprids took between 14 and 108 hours to explore a surface and permanently attach, before metamorphosing. This varied with species and location. 8. At Greenock and Mallaig, intra- and interspecific competition between B. crenatus and B. balanoides largely influenced the population levels on two and three month panels. The numbers of B. balanoides fell, while those of B. crenatus rose. Over longer periods, B. crenatus would probably displace B. balanoides completely. This may be related to the former species sublittoral habitat, faster time to metamorphosis, lower mortality, higher growth rate, and calcareous base.
- 1 - sciences appliquees, technologies et medecines
- 2 - sciences biologiques et medicales
- 3 - sciences biologiques fondamentales et appliquees. psychologie
- 4 - phytopathologie. zoologie agricole. protection des cultures et des forets