Sea cucumber is one of the resources under fishing pressure, which needs more knowledge and studies to manage its sustainability. This study was conducted to provide necessary information on the reproduction cycle, maturity evolution, size at first maturity and other parameters of Holothuria forskali, Holothuria sanctori, and Holothuria tubulosa in the M'diq Bay. The three species showed variability in the morphometric measurements with superiority for H.sanctori and H.tubulosa. The potential spawning period and the gonad index “GI" peaks were different from one species to another, with a larger spawning period and an important GI percentage for H. sanctori. The first maturity size was above 17.50cm and more than 250g for the three species. The environmental factors and GI correlation varied among the species under study. Furthermore, the percentage of potential individuals assumed in the spawning period did not manifest a correlation with the environmental factors for the three species. This work can provide a strong baseline for further studies in this region, introducing an important contribution to the management of the studied species in fisheries and acting as an essential opening for the three sea cucumbers farming in near geographical areas.