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. 2022 Dec;36(6):e13979.
doi: 10.1111/cobi.13979. Epub 2022 Sep 26.

Mussel parasite richness and risk of extinction

Joshua I Brian  1   2 , David C Aldridge  1   3
Affiliations

Mussel parasite richness and risk of extinction

Joshua I Brian et al. Conserv Biol. 2022 Dec.

Abstract
in English, Spanish

Parasite conservation is important for the maintenance of ecosystem diversity and function. Conserving parasites relies first on understanding parasite biodiversity and second on estimating the extinction risk to that biodiversity. Although steps have been taken independently in both these areas, previous studies have overwhelmingly focused on helminths in vertebrate hosts over broad scales, providing low resolution and excluding a large proportion of possible host and parasite diversity. We estimated both total obligate parasite richness and parasite extinction risk in freshwater mussels (Unionidae and Margaritiferidae) from Europe and the United States to provide a case study for considering parasite conservation in a severely understudied system. We used currently reported host-parasite relationships to extrapolate parasite diversity to all possible mussel hosts and then used the threat levels of those hosts to estimate the extinction risk for both described and undescribed parasites. An estimated 67% of parasite richness in freshwater mussels is undescribed and over 80% of the most host-specific groups (digenean trematodes and ciliates) are undescribed. We estimated that 21% of this total parasite fauna is at immediate risk of extinction, corresponding to 60 unique species, many of which will likely go extinct before being described. Given the important roles parasites play in community structure and function and the strong ecosystem engineering capacities of freshwater mussels, such extinctions are likely to severely affect freshwater ecosystems. Our detailed study of mussel parasites provides compelling evidence for the hidden conservation threat to parasites through extinction cascades and shows parasites are deserving of immediate attention.

La conservación de parásitos es importante para el mantenimiento de la diversidad y funcionamiento de los ecosistemas. La conservación de parásitos depende en primera instancia del entendimiento de la biodiversidad de parásitos y, en segunda, de la estimación del riesgo de extinción de esa biodiversidad. Mientras que se han tomado medidas en ambas áreas, estudios previos se han enfocado abrumadoramente en helmintos de hospederos vertebrados, proporcionando baja resolución y excluyendo a una amplia proporción de una probable diversidad de hospederos y parásitos. Estimamos tanto la riqueza de parásitos obligados como el riesgo de extinción de mejillones de agua dulce (Unionidae y Margaritiferidae) de Europa y Estados Unidos para proporcionar un caso de estudio para considerar la conservación de parásitos en un sistema severamente poco estudiado. Utilizamos las relaciones hospedero-parásito registradas hasta la fecha para extrapolar la diversidad de parásitos a todas las especies posibles de mejillones hospederos y luego utilizamos los niveles de amenaza de aquellos hospederos para estimar el riesgo de extinción tanto para parásitos descritos y no descritos. Alrededor de 67% de la riqueza de parásitos de mejillones de agua dulce no esta descrito, así como mas de 80% de los grupos específicos de hospederos (trematodos digeneos y ciliados) tampoco están descritos. Estimamos que 21% del total de esta fauna de parásitos está en riesgo inminente de extinción, correspondiendo a 60 especies únicas, muchas de las cuales probablemente se extinguirán antes de ser descritas. Dado la importancia del papel que desempeñan los parásitos en la estructura y función de la comunidad y las notables capacidades de los mejillones de agua dulce para la ingeniería del ecosistema, es muy probable que tales extinciones afecten severamente a los ecosistemas dulceacuícolas. Nuestro estudio detallado de los parásitos de mejillones proporciona evidencia convincente de la amenaza oculta para los parásitos mediante cascadas de extinción y muestra que los parásitos son merecedores de atención inmediata.

Keywords: ciliado; ciliate; coextinción; coextinction; mite; richness; trematode; trematodo; unionid; uniónido; Ácaro.

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Figures

FIGURE 1
FIGURE 1
(a) Number of host species for parasites in the four parasite groups in (a) European and (b) U.S. mussels (points, individual parasite species [jittered to aid visualization]; red diamonds, overall mean). Graphs have different x‐axis scales (Europe, linear; the United States, log) given the much higher number of possible total hosts in the United States
FIGURE 2
FIGURE 2
Total number of observations for each parasite (across all mussel hosts) correlated with the number of host species in which the parasite has been observed (shading, 95% CI of the fitted line). The line of isometry (dashed gray line) represents a 1:1 relationship between the host range and the total number of observations (e.g., a point lying on this line at [2, 2] or [10, 10] indicates a parasite has been observed once each in 2 or 10 hosts, respectively)
FIGURE 3
FIGURE 3
Predicted proportion of parasites that would go extinct for a given proportion of mussel hosts going extinct (solid lines, mean estimates; dotted lines, 95% CIs): (a) aspidogastreans, (b) digeneans, (c) mites, and (d) ciliates
See this image and copyright information in PMC

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References

    1. Alves, P. V. , Vieira, F. M. , Santos, C. P. , Scholz, T. , & Luque, J. L. (2015). A checklist of the aspidogastrea (Platyhelminthes: Trematoda) of the world. Zootaxa, 3918, 339–396. - PubMed
    1. Balvanera, P. , Daily, G. C. , Ehrlich, P. R. , Ricketts, T. H. , Bailey, S. A. , Kark, S. , & Pereira, H. (2001). Conserving biodiversity and ecosystem services. Science, 291, 2047. - PubMed
    1. Blasco‐Costa, I. , & Poulin, R. (2017). Parasite life‐cycle studies: A plea to resurrect an old parasitological tradition. Journal of Helminthology, 91, 647–656. - PubMed
    1. Boast, A. P. , Weyrich, L. S. , Wood, J. R. , Metcalf, J. L. , Knight, R. , & Cooper, A. (2018). Coprolites reveal ecological interactions lost with the extinction of New Zealand birds. Proceedings of the National Academy of Sciences, 115, 1546–1551. - PMC - PubMed
    1. Bolotov, I. N. , Klass, A. L. , Kondakov, A. V. , Vikhrev, I. V. , Bespalaya, Y. V. , Gofarov, M. Y. , Filippov, B. Y. , Bogan, A. E. , Lopes‐Lima, M. , Lunn, Z. , Chan, N. , Aksenova, O. V. , Dvoryankin, G. A. , Chapurina, Y. E. , Kim, S. K. , Kolosova, Y. S. , Konopleva, E. S. , Lee, J. H. , Makhrov, A. A. , … Vinarski, M. V. (2019). Freshwater mussels house a diverse mussel‐associated leech assemblage. Scientific Reports, 9, 1–22. - PMC - PubMed

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