The Biodiversity of Topshells in Pulau Pemanggil, Johor, Malaysia

A survey to study the diversity of topshells in Pulau Pemanggil, Johor was conducted. Observations were done using the random transect technique on four locations by scuba diving, snorkelling and reef walk. Two families of topshells were recorded in Pulau Pemanggil, namely Trochidae and Turbinidae. Trochidae is the dominant family where five out of six species of topshell recorded are Trochidae. The five species of Trochidae are Trochus niloticus, Tectus pyramis, Trochus stellatus, Trochus maculatus and Trochus histrio. The species from the Turbinidae family is Astralium calcar. Tectus pyramis and Trochus niloticus are the dominant species in Pulau Pemanggil (8 individuals/500 m2 for each species) while Trochus histrio is the least dominant species (1 individual/500 m2). Comparison among the topshell species within sampling locations at Pulau Pemanggil were done using four ecology indices, which are Simpson s Index (D), Shannon Weiner s Index, Evenness Index and Richness Index. Teluk Pa Kaleh showed the highest diversity of topshells compared with other locations in Pulau Pemanggil.