Hi Marine, I am not a specialist for holothurians, but Actinopyga mauritiana could be accurate - have a look here in SeaLifeBase https://www.sealifebase.se/summary/Actinopyga-mauritiana.html - on the landing page, you can chose Mauritius as a country and click e.g. on echinoderms to get the list of recorded species and then see the species summary page. Or have a look here: Purcell, S.W., Y. Samyn and C. Conand 2012 Commercially important sea cucumbers of the world. FAO, Rome, Italy, 223 p.
No picture of organisms which ignores their physical and organic environment can be even approximately complete. Studies of dead animals or their parts or even of living animals in the laboratory, valuable and indispensable as they are, give but partial pictures. In the studies here contemplated we seek a firsthand knowledge of living invertebrate animals in their natural setting, their behavior and interrelations, their distribution within the habitat, the influence of physical conditions on this distribution and the correlation between their structures and their behavior patterns on the one hand and the places they occupy in the environment on the other.