|Red List Category & Criteria:
||Clausnitzer, V., Dijkstra, K.-D.B. & Suhling, F. (Odonata Red List Authority)
Thalassothemis Ris, 1909 is a monotypic Mascarenan genus. T. marchali is restricted to rocky mountain forest streams and rivers. There are no records from cultivated areas. The species is known from the type, which was described in 1842, from a male caught in 1954 (Pinhey 1955) and from recent observations made by Andreas Martens. So far, there are four localitions known, three of which are situated in the SE mountains (A. Martens, unpubl.).
Mauritius has experienced a loss of 95% of its natural vegetation and less than 100 km² of Mauritius’ native vegetation is left (Safford 2001). Safford (2001, p. 584) that “even in reserves the native vegetation is progressively degrading, and this therefore presents a chronic problem for native wildlife”. In respect of these statements and its habitat requirements of Thalssothemis marchali — mountain forest streams and rivers — a drastic past, present and future decline is inferred for this species. With the current known four populations the area of occupancy is below 10 km² and the extent of occurrence below 100 km².