Differential substrate affinity between two giant clam species, Tridacna maxima and Tridacna squamosa, around Mauritius

  • Sundy Ramah University of Mauritius
  • Nawsheen Taleb-Hossenkhan University of Mauritius
  • Ranjeet Bhagooli University of Mauritius
Keywords: Giant clams, Tridacna maxima, Tridacna squamosa, Mauritius Island, substrate affinity


Giant clams have been mostly reported in the South Paci c and Indian Ocean. The aim of this study was to com- pare the substrate a nity between two species of giant clams, Tridacna maxima and T. squamosa. Field surveys were carried out in April and May 2016 within the reef areas of three geographically di erent sites around Mauritius Island: Black-River; Ile D’Ambre; and Belle Mare. Using triplicate (n=3) belt transects of 50m × 10m (500m2), giant clams were identi ed, quanti ed and the substrata to which they were attached were noted. Results indicated that 90% of T. maxima bore partially in colonies of Porites spp., potentially making them less vulnerable to natural and anthropogenic pressures. T. squamosa individuals, on the other hand, were more exposed as they were attached to at substrata such as dead plate corals or rubble. This di erence may be attributed to the shape of the giant clam shells. For instance the bottom section of T. squamosa’s shells are scaly as compared to that of T. maxima. This morpholog- ical di erence may be one of the factors that in uences the choice of substrate. Further investigations at additional sites will provide more information on the preference of substratum by these highly valued Tridacnid species and inform appropriate conservation and management approaches. 

Author Biographies

Sundy Ramah, University of Mauritius
Mphil/PhD student, Department of Biosciences, Faculty of Science
Nawsheen Taleb-Hossenkhan, University of Mauritius
Head of Department, Department of Biosciences, Faculty of Science
Ranjeet Bhagooli, University of Mauritius
Senior Lecturer, Department of Marine & Ocean Science, Fisheries & Mariculture, Faculty of Ocean Studies

Journal Identifiers

eISSN: 0856-860X
print ISSN: 0856-860X