Abstract—Gharb (northwest) is the area in Morocco where rice planting is very important due to its considerable water resources. The area is crossed by the tributaries of the Sebou river over a length of about 225 km before flowing into the Atlantic Ocean at Mehdia city in Morocco. Recently, an invasive classified crayfish has been introduced: the red swamp crayfish Procambarus clarkii. Colonization by this species has been monitored over the past three years in the study area. A survey was conducted between 2016 and 2018, to establish a geographical expansion of the species in the Gharb area, the evolution of the population in the rice fields, and to identify some impacts of this species on rice field. The results support the hypothesis of faster colonization downstream. It rapidly colonized the Gharb area and the evolution of its population in the rice fields between 2016 and 2018 is considered explosive, the main stages of this colonization can be summarized as follows: In 2016: explosive phase, In 2017: slowdown of the explosive phase, In 2018: return to the explosive phase.

Index Terms—Procambarus clarkii, propagation map, Gharb, Sebou River, rice fields, Morocco

Cite: Sara Saguem and Majida El Alami El Moutaouakil, "Assessment of the Red Swamp Crayfish, Procambarus Clarkii (Girard, 1852) in Northwest of Morocco: Spread and Evolution of the Population on Agricultural Products——Case of Rice Fields," International Journal of Pharma Medicine and Biological Sciences, Vol. 9, No. 3, pp. 122-128, July 2020. doi: 10.18178/ijpmbs.9.3.122-128

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