How did you first become interested in parasitology and aquatic organisms?

Since I was a child, I love fish, the sea, water… I studied a BSc in biomedical research at Mexico´s National University (Universidad Nacional Autónoma de México) and have always been a bit “bipolar”: simultaneously interested in both basic scientific questions and the application of science to solve practical problems. In university, I started scuba-diving and became fascinated by parasites – in particular, taeniid tapeworms, who can immunosuppress hosts and become “perfect transplants”, as my teacher Carlos Larralde used to say. A PhD in fish parasitology was a nice way to combine some of my interests and passions. I was fortunate to get a scholarship to study in the University of Bristol, UK under the mentorship of Richard Tinsley. My thesis dealt with the interaction of the monogenean Discocotyle sagittata and trout, both in the field (fish farms, rivers) to analyse the epizootiology and the impact of infection on farmed fish, and in laboratory settings to understand the immune mechanisms regulating the host-parasite interaction – a full “bipolar” experience! (recently summarized in Tinsley et al. 2025)

What has kept you engaged in the field over the years?

First, my enduring love and fascination for aquatic organisms – which now obviously extends to parasites! Also, the ability to engage in trying to solve interesting questions. I am pleased to have been able to use taxonomy as a cornerstone to understand ecological, biogeographical, evolutionary questions – and to interact with and learn from colleagues in other disciplines.

Why is this area of research continuing to be important and exciting?

It is interesting to be able to use parasites to understand how life has evolved in a geologically-complex and biodiverse country like Mexico – and how it continues to evolve in the Anthropocene, which has novel challenges, like invasive species. It is important to understand how “life” (i.e, species, populations, communities, ecosystems, etc.) came to be what is it today, to be able to protect and foresee shifts in a changing world – both tor basic (e.g., conservation) and applied reasons (e.g., aquaculture health).

In regards to the Collection, where did the original idea come from?

Simonetta Mattiucci, Gerardo Pérez-Ponce de León and myself had the opportunity to meet and chat during the XI International Symposium on Fish Parasites (ISFP), held in Mérida, Mexico in January 2025. Gerardo and myself were part of the XI ISFP organizing committee; Simonetta is part of the editorial board of Parasitology Research – and the three of us have been friends and colleagues for years! I met Simonetta at the VII ISFP, celebrated in Viterbo, Italy in 2007. Anyway, after the conference, we received Simonetta's nice invitation to guest edit a Collection on the effects of the Anthropocene on fish parasites – a topic that had popped up in several of the presentations and discussions at the XI ISFP (see Rubio-Godoy et al., 2025).

Was there a particular discussion, meeting, challenge, or observation that inspired it?

Both during the review of the conference abstracts, as well as during several of the sessions, certain themes came up time after time, like invasive species or the effect of a warming world on organisms, manifested as changes in abundance and/or distribution, modified survival, infectivity or pathogenicity, etc. – the obvious common thread was the Anthropocene.

Why did you feel this topic deserved a dedicated Collection?

We felt this topic deserved a dedicated Collection for different reasons. One, that the Anthropocene is THE overarching scientific topic of our age, and parasitologists can and should participate in it for various reasons – among these, the realization that parasites are a fundamental component of ecosystems and their comprehension and conservation has huge implications. One of the things the Collection provides evidence for, is the usefulness of parasites as finely tuned biological indicators of ecosystemic changes. A further reason to dedicate a Collection to aquatic parasites is that invasion biology, like other disciplines, has until now basically assumed parasites are not relevant and we can provide evidence to prove they are – as we managed to do with several examples in this Collection.

What stood out to you most?

One recurring topic is that of invasive alien species, which are featured in several of the papers contained in the Collection. It is obvious that the impact of biological invasions must be studied case-by-case, as some fish hosts lose their parasites upon translocation (enemy release), some pass them on to the invaded ecosystems (overspill) and some acquire –and sometimes amplify– native parasites (spillback), regardless of the time frame, as illustrated in studies of parasites co-introduced from 150 to 15 years ago.

One topic that caught my attention is the possibility to witness evolution occurring right before our eyes: changing environmental conditions lead to modified distributions, and these potentially lead to contact and hybridization between previously separated lineages, as some papers in the Collection elegantly show. It was nice to catch evolution in the act!

What are the most pressing questions researchers should be tackling next?

Perhaps one of the most pressing questions parasitologists and other experts should address is the characterization and measurement of the impact(s) of invasive parasites, particularly in the Global South – the lists of invaders are out there! As in several other topics (e.g. adoption of molecular techniques), parasitology is lagging behind and it’s about time we try to catch up.

Lastly, what do you hope readers take away from this collection?

I hope that readers of the Collection are convinced that parasitology of aquatic organisms is alive and kicking! That is, that the field has many important advances and unresolved questions that need to be looked at, preferably from different angles and by new eyes – I hope that this Collection contributes to attract new inquisitive minds to the field!

References:

1. Rubio-Godoy M, Aguirre-Macedo L, García-Varela M, Grano-Maldonado MI, Guillén-Hernández S, Rodríguez-Santiago MA, Smit NJ, Vidal-Martínez VM & Pérez-Ponce de León G. 2025. The XI International Symposium on Fish Parasites: fish health, parasite biodiversity and conservation. Trends in Parasitology 41: 251–260. DOI: 10.1016/j.pt.2025.02.006

2. Tinsley RC, Carey AM & Rubio-Godoy M. 2025. The impact of helminth infection in fish farms on wild trout populations: host immune regulation of disease risk. Parasitology 152: 1367–1380. DOI: 10.1017/S0031182025101029