Occurrence of the invasive Caprella scaura Templeton, 1836 (Amphipoda: Caprellidae) in the Marchica coastal lagoon (Alboran Sea, Morocco).
Non-indigenous species are a recognized worldwide threat to biodiversity, to the economy and even to human health. Hence, analysis of principal descriptors of their occurrence is pivotal to set reliable conservation strategies and appropriate management. In this paper, we have reported the first record in the Marchica lagoon (Southern Alboran Sea) of the invasive Caprella scaura Templeton, 1836, an amphipod species likely native to the Indian Ocean and now recorded worldwide. Caprella scaura is widely distributed in the lagoon, and its abundance fluctuated between 3 and 337 ind./m2. The species is well established in the Marchica lagoon and spreads over various ranges of depth (0.4 to 7.7 m), water temperature (14.21-28.97°C), salinity (32.28-38.04) and substrates (bare and vegetated). This clearly confirms its large plasticity and highly invasive behaviour. The species has been introduced to the Marchica lagoon most likely via shipping activity. The recent settlement of three well established invasive species in the Marchica lagoon (Bursatella leachii Blainville, 1817, Callinectes sapidus Rathbun, 1896 and Caprella scaura) reveals that this coastal ecosystem is at risk of biological invasions and has to be monitored regularly in order to evaluate potential ecological impacts on the ecosystem.