Taxonomy 2028 Challenge: Collection and characterisation of parasites and symbionts alongside their hosts

Posted on behalf of Dan Huston - PhD Candidate, School of Biological Sciences, The University of Queensland

Organisms do not exist in isolation. Rather they exist in a web of complex associations with other organisms across space and time. Parasites and other symbionts are intimately associated with their host organisms and represent a massive component of global biodiversity. This component is mostly unseen, and rarely considered during biodiversity and ecological surveys or in conservation planning. Threats to biodiversity are amplified in parasite and symbiont populations, and host-specific lineages are likely to face extinction before their hosts. If we seek to characterise all of Earth’s biodiversity then, we must consider symbionts. Obviously, study of these organisms requires examination of their hosts, and therefore presents excellent collaborative opportunities for systematic biologists working on various groups. However, most parasites and symbionts have specific collection protocols required for producing specimens of a quality useful for taxonomy. Therefore I propose that:

By 2028, we will have established and implemented a collaborative support network dedicated to the collection and characterisation of parasites and symbionts, alongside characterisation of their hosts.

It could be called something that would result in a hip acronym like ‘Systematics of Symbionts and Parasites Support Network’ (SSAPSN). The major goal of the network would be to facilitate parallel host and symbiont collection efforts through coordinated collecting expeditions and training about parasite and other symbiont collection techniques. This will result in more impact per unit of collecting effort and more complete biodiversity collections in museums and other institutions for current and future research. Collaborative efforts between those systematic biologists studying hosts, and those studying the symbionts of said hosts may be seen as a better value for money and could increase grant application success, and may lead to cross-field citations of research papers. Most importantly, such efforts will give us a better understanding of life and the complex interactions between organisms in general.

Examples of the importance of considering parasites and symbionts in the future of taxonomy and systematics can be gleaned from many of the challenges already posted here on Noto | Biotica. Elaine Davidson’s challenge to explore the diversity and potential of microorganisms highlights the value these organism have to humans in terms of medicine, agriculture and industry. The many endosymbiotic microorganisms present in plants and animals are sure to provide novel chemical processes and enzymes of value to us. Kevin Thiele’s posts ‘every Australasian species genomed’ and ‘life in the late Anthropocene’ challenge us to collect tissue samples for all Australasian biota and sequence their genomes. While many of the tissue samples required are already in museums, such an endeavour will still require a huge collecting effort. These collecting events should be coordinated between systematic biologists across disciplines so that both host tissue and symbiont tissues can be collected concurrently. Nerida Wilson challenged us to double the number of described coral reef taxa by 2028. This topic hits close to home as much of my PhD research has been on coral reef parasites. We have only just begun to scratch the surface in terms of understanding parasite and symbiont diversity on the Great Barrier Reef and increased effort in characterising these organisms will greatly aid in doubling the number of described species for the region. Juliet Wege’s post ‘Obtain high quality collections of all undescribed vascular plant taxa’ highlights the difficulties inherent in acquiring these specimens from remote areas, and the need to execute targeted field expeditions to take advantage of seasonal weather conditions. Expeditions for rare plants could benefit from a nematologist to collect and study plant-parasitic nematodes and an entomologist to collect and study associated insects. A simple alternative would be training in the collection of these organisms for the botanists tasked with undertaking such expeditions. I fully understand that having collectors plan on collecting symbiont organisms alongside the stuff they are really interested in is a big ask, so including extra personnel on such expeditions focused on symbionts would be ideal. In the end however, any collection would be better than none.

The obvious first step towards building such a network is a level of organisation and a platform for communication. The existence of the SASB and now Noto | Biotica already gets us most of the way there. Noto | Biotica could be used as a news platform to help connect parasite and symbiont systematic biologists with those studying other groups, coordinate collection events, ‘wanted organism’ ads, etc. Because many parasites and symbionts are hidden in not so obvious locations in their hosts, and many require specialised fixation and preservation, workshops designed to train other systematic biologists in how to find these organisms and how to preserve them would be beneficial. Perhaps some small grants could become available for biologists undertaking collecting expeditions to cover the cost of extra field days and equipment to collect symbionts, or perhaps travel grants could be used to bring a parasitologist (we make for interesting dinner conversation) along on the trip. At the very least, a better awareness of all those organisms that exist under cover of their host is sure to lead to significant progress in the task of characterising all of Earth’s biota.