SummaryThe family Hydrophilidae is the largest group of the superfamily Hydrophiloidea to which the largest aquatic Polyphaga are allocated. Phylogenetic studies based on morphological characters suggest that in Hydrophilidae, specifically in Hydrophilini, the body size is related to the group evolution. Despite these morphological analyses, cytogenetic studies of this family are scarce, and there is not a correlation of morphologic and cytogenetic data outlined for this group. In this paper, we analyzed seventeen specimens of Tropisternus mutatus sapucay Fernández & Bachman from rivers from two localities in Southern Brazil. Chromosome analyses showed 2n=18 with a sex chromosome system of the Xy p type (2n=18=16+Xy p ). All the autosomes, including the X p chromosome, were metacentric. The basal number and the possible divergence among the different Hydrophilidae species analyzed to date, as well as the phylogeny proposed for Hydrophilini, are discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.