Abstract
<jats:p>This paper presents a comprehensive analysis of the scientific and museum legacy of one of the leading contemporary Ukrainian ichthyologists, Candidate of Biological Sciences, Senior Researcher at the National Museum of Natural History of the National Academy of Sciences of Ukraine — Leonid Heorhiiovych Manilo (1953–2024), whose scientific activity constituted an important stage in the development of studies on the ichthyofauna of marine and freshwater ecosystems. The article highlights the main directions of his research, including systematics and taxonomy of fishes, studies of biodiversity and the structure of aquatic biocenoses, as well as investigations of the ichthyofauna of the western Indian Ocean, the Azov–Black Sea region, and Antarctica. It is demonstrated that the scholar’s scientific contribution is characterised by a wide geographical scope, an integrative approach, and a high level of generalization of empirical material. Particular attention is paid to his distinctive and recognisable methodological approach, combining detailed morphological analysis with biogeographical interpretation, which subsequently became a foundation of his research. Of special value are his studies devoted to the genera Parapercis Bleeker, 1863, Epigonus Rafinesque, 1810, representatives of Gobiidae G. Cuvier, 1816, and other taxonomically challenging groups, where L. H. Manilo applied detailed comparative morphometric analysis to refine diagnostic species characters. Considerable attention is given to his contribution to the development of ichthyological collections in museum institutions, particularly to the formation of representative collections comprising materials from various biogeographic regions of the world—from the Black and Azov Sea basins to the southern latitudes of the World Ocean. These collections include both common and rare species and serve as an important basis for taxonomic and faunistic studies, as well as for modern systematic revisions. It is emphasised that the researcher’s publications significantly contributed to a deeper understanding of the structure of ichthyofauna, the dynamics of its changes, and the processes of biodiversity formation in aquatic ecosystems. His role in the development of international scientific collaboration and in the integration of Ukrainian ichthyological research into the global scientific community is also highlighted. The scientific legacy of the scholar is regarded as an important addition to modern ichthyology.</jats:p>