Biases and gaps in freshwater mollusks research in Latin America and the Caribbean: a multi-decadal bibliometric analysis (1976–2024)

Freshwater molluscs play key ecological roles in aquatic ecosystems, yet they are among the most threatened and least studied invertebrate groups worldwide. This study evaluates how scientific knowledge on freshwater molluscs is structured across Latin America and the Caribbean, testing the hypothesis that research effort is uneven and shaped by multiple knowledge shortfalls that constrain ecological understanding and conservation planning. We conducted a bibliometric review of peer-reviewed literature indexed in Web of Science, combining systematic screening with quantitative bibliometric analyses to assess geographic coverage, taxonomic focus, research themes, collaboration networks and gender representation in authorship. Our results reveal pronounced Wallacean and taxonomic shortfalls, with research concentrated in a limited number of countries and disproportionately focused on invasive species, whereas many native and threatened taxa remain poorly studied. We also detected thematic gaps related to evolutionary and physiological processes, alongside fragmented collaboration networks and persistent gender asymmetries, reflecting broader shortfalls in biodiversity research. These patterns indicate a mismatch between research effort and conservation priorities in a megadiverse region facing increasing environmental pressures. By identifying critical blind spots in current knowledge, this study offers a regional framework to guide future ecological research, conservation strategies and collaborative initiatives on freshwater mollusc management globally.