A few benthic and planktonic samples caught between November 1972 and February 1975 along the west coast of Madagascar revealed the presence of ten species of mysidaceans belonging to the sub-order Lophogastrida, two of which new to science. These are Gnathophausia ingens, G. zoea, G. gracilis, Lophogaster intermedius, L. neocaledonensis, L. anoplos n.sp., Pralophogaster glaber, Eucopia sculpticauda, E. australis and E. crassicornis n.sp. Remarks are made on speciation processes in this area characterized by the presence of low oxygene content intermediate waters.
Crustacea, Mysidacea, Lophogastrida, systematics, ecology, Indian Ocean.