From individuals to populations: molecular analyses, population genetics and modern phylogenetic approach (MPA) applied to different aquatic organisms.

The primary aim of this doctoral project is to harmoniously blend molecular and phylogenetic analyses in the exploration of three case studies centered around aquatic organisms. In particular, I focused my attention on two species Pinna nobilis and Salariopsis fluviatilis , which are experiencing different conservational issues and on third species Procambarus virginalis, which conversely represents in its present range of distribution a threat to the autochthonous biodiversity. Pinna nobilis, the largest bivalve mollusc native to the Mediterranean Sea, holds a unique and endemic status in this region (Butler et al. 1993). This species plays a pivotal role in marine ecosystems since it serves a dual purpose in conservation efforts, being both a flagship and a keystone species (see Scarpa et al. 2021; Nebot Colomer et al. 2022 a , and references therein). Currently, Pinna nobilis is under a severe threat due to recent mass mortality events that have affected its populations throughout the Mediterranean Sea (Scarpa et al. 2020). Salariopsis fluviatilis is a benthic fish species which inhabits the freshwater ecosystems of various Mediterranean countries (Zander 1986). Presently, the species is experiencing a significant decline in local populations due to its vulnerability to environmental changes and pollution Laporte et al. 2014). The underlying causes are frequently linked to habitat fragmentation and can be aggravated by factors like eutrophication, water pollution in lakes, and the introduction of invasive predators (Laporte et al. 2014). Procambarus virginalis, on the other hand, is an alien freshwater crayfish species, whose presence in Europe was first reported in the mid 1990s (Scholtz et al. 2003). This species is considered a perfect invader due to its capability to reproduce through parthenogenesis (Chucholl et al. 2012). Its presence in European freshwater habitats poses numerous threats, including competition with native crayfish, as well as potential adverse effects on amphibians, invertebrates, and the environment. These threats arise from intraspecific and interspecific competition, the potential transmission of crayfish plague, and its ecosystem altering activities Oidtmann et al. 1999 ; Souty Grosset et al. 2016 ; Statzner et al. 2003). Moreover during the doctoral years, the analytical approach employed in the study of aquatic organisms was consistently applied to additional projects focusing on terrestrial organisms. Specifically, the studies conducted during this period focus the attention on Taenia saginata , Fasciola hepatica and, Canis lupus familiaris . In conclusion, the present thesis includes five articles in internationally peer reviewed journals and one internationally peer reviewed book chapter.

The primary aim of this doctoral project is to harmoniously blend molecular and phylogenetic analyses in the exploration of three case studies centered around the study of the genetic variability of aquatic organisms. In particular, I focused my attention on two species Pinna nobilis and Salariopsis fluviatilis, which are experiencing different conservational issues and on third species Procambarus virginalis, which conversely represents in its present range of distribution a threat to the autochthonous biodiversity. Pinna nobilis, the largest bivalve mollusc native to the Mediterranean Sea, holds a unique and endemic status in this region (Butler et al. 1993). This species plays a pivotal role in marine ecosystems since it serves a dual purpose in conservation efforts, being both a flagship and a keystone species (see Scarpa et al. 2021; Nebot Colomer et al. 2022 a , and references therein). Currently, Pinna nobilis is under a severe threat due to recent mass mortality events that have affected its populations throughout the Mediterranean Sea (Scarpa et al. 2020). Salariopsis fluviatilis is a benthic fish species which inhabits the freshwater ecosystems of various Mediterranean countries (Zander 1986). Presently, the species is experiencing a significant decline in local populations due to its vulnerability to environmental changes and pollution (Laporte et al. 2014). The underlying causes are frequently linked to habitat fragmentation and can be aggravated by factors like eutrophication, water pollution in lakes, and the introduction of invasive predators (Laporte et al. 2014). Procambarus virginalis, on the other hand, is an alien freshwater crayfish species, whose presence in Europe was first reported in the mid-1990s (Scholtz et al. 2003). This species is considered a perfect invader due to its capability to reproduce through parthenogenesis (Chucholl et al. 2012). Its presence in European freshwater habitats poses numerous threats, including competition with native crayfish, as well as potential adverse effects on amphibians, invertebrates, and the environment. These threats arise from intraspecific and interspecific competition, the potential transmission of crayfish plague, and its ecosystem altering activities Oidtmann et al. 1999 ; Souty Grosset et al. 2016 ; Statzner et al. 2003). Moreover, during the doctoral years, the analytical approach employed in the study of aquatic organisms was consistently applied to additional projects focusing on terrestrial organisms. Specifically, the studies conducted during this period focus the attention on Taenia saginata, Fasciola hepatica and, Canis lupus familiaris. In conclusion, the present thesis includes five articles in internationally peer reviewed journals and one internationally peer reviewed book chapter