Morphological and molecular assessment of Livoneca redmanii Leach, 1818, and Anilocra alloceraea Koelbel, 1878 (Isopoda: Cymothoidae) from Egyptian waters

Background Two cymothoid isopod species, Livoneca redmanii Leach, 1818 and Anilocra alloceraea Koelbel, 1878, have been discovered throughout the research period. These species have been morphologically compared to other closely related species. Their species sequences have been determined using mitochondrial cytochrome c oxidase subunit I (COI) gene fragments and compared to previously identified Livoneca and Anilocra species. The present study aims to provide a detailed morphological description along with parasitological indices of the L. redmanii species in the Mediterranean, which has previously been described in Egypt by several researchers using various misidentifications. Results According to the study findings, Livoneca redmanii was accidentally introduced into Qarun Lake with fish fry from the Mediterranean Sea. The morphological and parasitological descriptions of Anilocra alloceraea and L. redmanii are discussed. Additionally, A. alloceraea species is considered the first to be documented on the Egyptian marine coast. Conclusions Livoneca redmanii species can rapidly adapt to favorable conditions and be found among the most prevalent species in Egyptian marine environments. Our study supports the description of L. redmanii males, as well as some additional morphological features of both cymothoid species females. The discovery of these species in Egyptian waters has extended their geographic distribution. Additionally, this study marks a significant advancement in our knowledge of the dynamics of some parasitic isopod distribution among their preferred species as well as a critical step toward identifying the species that indeed inhabit Egyptian waters.