The holothurian (Echinodermata) diversity of the Glorieuses Islands (Eparses Islands, France, Mozambique channel)

  • Chantal Conand Laboratoire Ecologie Marine, Université de La Réunion, 97715 Saint Denis, La Réunion, France. Email: conand@univ-reunion.fr Muséum Histoire Naturelle, 43 rue Cuvier, 75005 Paris, France
  • T Mulochau Aquarium de La Réunion, Port de plaisance, 97434 Saint-Gilles les Bains, France
  • P Chabanet IRD, CS 41095, 97495 Ste Clotilde cedex, La Réunion, France
Keywords: , holothurian, diversity, occurrence, coral reefs, Western Indian Ocean Short tittle, Holothurians of Glorieuses islands Indian Ocean

Abstract

Glorieuses archipelago is one of the Eparses Islands, French islands scattered in the Mozambique Channel (Western Indian Ocean). These isolated coral islands, without permanent human population, are important to evaluate the evolution of biodiversity without direct anthropogenic influence. Among several aims, the program BioReCIE (Biodiversity, Resources and Conservation of Eparses Islands) was to complete the inventories of several groups including the holothurians (Echinodermata). In November 2012, a multidisciplinary team explored the reef slopes of the island by scuba diving down to 20 meters (10 sites), and the reef flats at low tide (12 sites) collecting specimens and taking photos for identification. The total holothurian richness was 20 species; 10 species were collected on the slopes and 15 on the reef flats. Given the limited number of sites studied, the occurrence of the different species in each class is presented as frequent, infrequent or rare. The commercial species Holothuria nobilis, Bohadschia atra and B. subrubra were frequent but illegal fisheries on holothurians are already occurring. Temporal comparisons at local and regional scales using the same methodology show that the diversity in Glorieuses is high and suggests that the biodiversity is increasing as we go from South to North in the Mozambique channel, as observed also for other taxa associated with coral reefs (fish and hard corals). 

Published
2014-08-08
Section
Articles

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