International Journal of Aquaculture, 2024, Vol.14, No.3, 126-138 http://www.aquapublisher.com/index.php/ija 136 environments, but complete transitions to freshwater occurred only a few times, making it difficult to generalize findings across different taxa (Lo et al., 2015). The reliance on molecular phylogenetic frameworks and fossil evidence also introduces uncertainties, as these methods can sometimes yield conflicting results or lack the resolution needed for fine-scale biogeographic reconstructions (Lo et al., 2015). 9.2 Research gaps and opportunities Despite the progress made, several research gaps remain that present opportunities for future studies. One notable gap is the limited understanding of the origins of biodiversity in freshwater habitats, which, despite their small area, exhibit high species richness and exceptional phylogenetic diversity (Román‐Palacios et al., 2022). Further research is needed to elucidate the evolutionary processes that have led to such high diversity in these habitats and to understand the conservation importance of freshwater ecosystems (Román‐Palacios et al., 2022). Another area ripe for exploration is the temporal patterns of marine endemism and tropical provinciality. The current understanding is based on time-calibrated molecular phylogenies and ancestral biogeographic estimates, but increased precision and sampling of geographic ranges are needed to refine these patterns. This could help in identifying areas of species creation and demise more accurately and in understanding the multiple historical processes involved in the origin and maintenance of marine biodiversity hotspot. 9.3 Emerging trends and innovations Emerging trends and innovations in the study of aquatic biodiversity are promising and could address some of the existing challenges. Advances in molecular techniques and genomic data are providing more detailed and accurate phylogenetic trees, which can improve our understanding of species diversification and biogeographic patterns. For example, the use of multi-gene datasets has allowed for a more comprehensive reconstruction of the historical biogeography of the Sciaenidae family, revealing previously unrecognized lineages and complex habitat transitions. Additionally, the integration of ecological and evolutionary data is becoming increasingly important. Studies that combine phylogenetic diversity with ancestral biogeographic estimation are beginning to show how assemblage structures and tropical provinciality have changed over time, offering new insights into the dynamics of biodiversity. These integrative approaches are likely to become more prevalent, providing a more holistic understanding of the origins and maintenance of aquatic biodiversity. While significant methodological challenges and research gaps remain, the field of aquatic biodiversity is poised for exciting advancements. By leveraging emerging trends and innovations, researchers can continue to unravel the complex phylogenetic patterns and historical biogeography that underpin the rich diversity of life in aquatic environments. 10 Concluding Remarks The study of aquatic biodiversity has uncovered complex patterns influenced by phylogenetic and biogeographic processes, as revealed by extensive literature reviews. Key findings emphasize habitat-specific richness, with terrestrial habitats, despite covering only 28% of Earth's surface, hosting the majority of species. In contrast, marine habitats cover 70% of the planet but have fewer species, while freshwater habitats show high richness and exceptional phylogenetic diversity despite covering just 2% of the surface. The South American freshwater ichthyofauna, enriched by marine-derived lineages, reflects historical biogeographic patterns shaped by vicariance, dispersal, and extinction events. Additionally, elevational gradients impact bacterial diversity, with local environmental factors playing a crucial role. The biogeographic history of eelpouts suggests that speciation and dispersal within areas are key, with minimal evidence that ocean cooling affects diversification. Cross-kingdom biogeographic structures are consistently driven by environmental conditions and anthropogenic stressors among marine metazoans, protists, and bacteria. The study also highlights the importance of integrating phylogenetics with biogeography to understand the origins and maintenance of aquatic biodiversity. Phylogenetic analyses shed light on evolutionary relationships and
RkJQdWJsaXNoZXIy MjQ4ODYzNA==