The present volume is the second volume dedicated to Alain Crosnier who passed away on 18 February 2021. Madagascar and more generally the South Western part of the Indian Ocean had a special place in his heart. From 1970 to 1976, he directed the ORSTOM Centre in Nosy Be in Madagascar where he explored the seabed to a depth of more than 1,000 m, thus discovering new resources and new species. The second part of his career was devoted to crustacean systematic and the exploration of the deep benthos of tropical areas. In addition to the deep-sea cruises, which he instigated for a long time, he deployed his visionary energy to organise the study of the collected specimens —by bringing specialists from all over the world to Paris— and to publish these results. In 1999, the “MUSORSTOM cruises” became Tropical Deep-Sea Benthos; the programme celebrated its 40th anniversary in 2016.
This second volume is a compilation of two major articles, on crustaceans Chirostylids and corals Stylasterids from South-West Indian Ocean. In this volume, keys to species, descriptions, colour illustrations and drawings, maps and compilation of species occurrences as well as descriptions of new species are provided at regional scale. With a total of 85 new species, i.e. 60 new species of Chirostylids and 25 new species of Stylasterids, this volume provides new knowledge on crustaceans and corals from South West Indian Ocean and conclusions about biogeography in this area are also presented in this volume.
Laure Corbari and Magalie Castelin are research-scientist and respectively curators of crustaceans and cnidarians collections of the Muséum national d’Histoire naturelle from Paris.