Reflections on ecology - discussion papers on ecological topics
Experimental analyses of small-scale associations with features of habitat by juvenile intertidal gastropods: looking at the difficult part of their life-history
Underwood, A.J.
World Congress of Malacology (Molluscan Megadiversity: Sea, Land and Freshwater)
University of Western Australia, Fisheries Research and Development Corporation, Western Australian Museum and Unitas Malacologica.
University of Western Australia, Perth
11-16 July 2004
Click on these links to scroll down to the following
categories:
The associations of densities of very early recruits of mobile intertidal species with features of their habitat have rarely been examined in the field. Here, experimental manipulation of local topography (by provision of cracks, grooves and pits of various sizes) demonstrated species-specific responses by animals naturally recruiting into experimental plots. Densities of juveniles (< 3 mm) of snails, Austrocochlea porcata, Bembicium nanum and Nerita atramentosa and limpets, Cellana tramoserica and Patelloida latistrigata, varied among experimental topographies in consistent ways. Only N. atramentosa and P. latistrigata showed increased density per area of shore. In the former case, provision of grooves and large pits also caused enhanced densities on open surfaces. P. latistrigata had decreased densities on open surfaces, but very much enhanced densities in grooves and other features, thus increasing total numbers in an area. The experiments are difficult because of small numbers of animals recruiting from the plankton and the great variability in numbers from time to time and place to place. Persistence and patience do, however, pay off in terms of insights into the least-understood part of the intertidal life-history of gastropods.
