Is parasite taxonomy really in trouble? A quantitative analysis.

In recent years, several authors have warned that the number of trained experts in parasite taxonomy and systematics is declining rapidly, and that the whole field is at risk. However, to date there has been no quantitative analysis to support these claims. Here, we provide the first such assessment, focusing on helminths parasitic in fish as an example, and using a representative dataset comprising over 2000 helminth species described in the past two decades. Based on standard indices of inequality, we demonstrate that a small group of highly prolific taxonomists are associated with the vast majority of new species descriptions, indicating that the research output in parasite discovery is concentrated in the hands of a small number of individuals. This situation has not improved over time. Furthermore, there has been no turnover over time, i.e., no replacement of the most prolific taxonomists: the individual researchers ranking among the most prolific describers of new parasite helminth species in the past decade were generally also the most prolific in the decade before that. Finally, based on the year in which these most prolific taxonomists published their first species description, we estimate that a large proportion of them are in the latter stages of their career. Inequalities in research output are the norm across scientific disciplines. However, persistent inequality in the number of species description per author, coupled with the same individuals ranking as most prolific over time and a majority of them in late career, all combine to support earlier claims that parasite taxonomy may well face a crisis in the form of an impending loss of taxonomic expertise.