Growth rate, distribution, and abundance of the introduced topshell Trochus niloticus Linnaeus on Guam, Mariana Islands
Smith BD. 1987. Growth rate, distribution, and abundance of the introduced topshell Trochus niloticus Linnaeus on Guam, Mariana Islands. Bulletin of Marine Science. 41(2):466-474
Growth rates of the introduced topshell Trochus niloticus on Guam, Mariana Islands, were studied with a mark and recapture method. Although growth rates of individuals varied considerably, a negative correlation was found between growth rate and initial shell diameter. The von Bertalanffy growth model parameters k and L(infinity) were calculated on the basis of 322 recaptures. Spatial distribution and abundance of T. niloticus were surveyed at sites characterized by wide reef flats, narrow reef flats, and limestone benches. Low densities of topshells were found on windward reefs, and leeward reefs supported greater densities. Distinct zonation of size classes of topshells was found for the outer reef flat, reef margin, 6-m contour, and 12-m contour. The size distribution of T. niloticus appears to be related to reef topography.
- Type
- Journal Article
- Authors
- Smith, Barry
- Units
- WAPA
- Keywords
- Abundance (Biodiversity), Animal Studies, Distribution, Distribution (Biodiversity), Exotic Species, Growth, Guam, Mark and Recapture, Observations, Population, Presence (Biodiversity), topshell, Trochus niloticus Linnaeus, von Bertalanffy growth model