Skip to main content Accessibility help

The geography of parasite discovery across taxa and over time

  • Robert Poulin (a1) and Fátima Jorge (a1)


We need reliable data on the spatial distribution of parasites in order to achieve an inventory of global parasite biodiversity and establish robust conservation initiatives based on regional disease risk. This requires an integrated and spatially consistent effort toward the discovery of new parasite species. Using a large and representative dataset on the geographical coordinates where 4943 helminth species were first discovered, we first test whether the geographical distribution of parasite species reports is spatially congruent across helminth higher taxa; i.e. whether areas, where many trematodes are found, are also areas where many nematodes or cestodes have been discovered. Second, we test whether the global geographical distribution of new helminth species reports has changed significantly over time, i.e. across the last few decades. After accounting for spatial autocorrelation in the data, we find no strong statistical support for either of the patterns we investigated. Overall, our results indicate that helminth species discoveries are both spatially incongruent among higher taxa of helminths, and inconsistent over time. These findings suggest that the global parasite discovery effort is inefficient, spatially biased and subject to idiosyncrasies. Coordinated biodiscovery programmes, involving research teams with expertise in multiple taxonomic groups, seem the best approach to remedy these issues.


Corresponding author

Author for correspondence: Robert Poulin, E-mail:


Hide All
Aguilar-Aguilar, R, Salgado-Maldonado, G, Contreras-Medina, R and Martinez-Aquino, A (2008) Richness and endemism of helminth parasites of freshwater fishes in Mexico. Biological Journal of the Linnean Society 94, 435444.
Beveridge, I and Jones, MK (2002) Diversity and biogeographical relationships of the Australian cestode fauna. International Journal for Parasitology 32, 343351.
Bivand, R and Piras, G (2015) Comparing implementations of estimation methods for spatial econometrics. Journal of Statistical Software 63, 136.
Bivand, RS, Hauke, J and Kossowski, T (2013) Computing the Jacobian in Gaussian spatial autoregressive models: an illustrated comparison of available methods. Geographical Analysis 45, 150179.
Bjørnstad, O. N. (2013). ncf: Spatial nonparametric covariance functions. R package version 1.1-5. Available at
Brooks, DR and Hoberg, EP (2001) Parasite systematics in the 21st century: opportunities and obstacles. Trends in Parasitology 17, 273275.
Cribb, TH (2004) Living on the edge: parasite taxonomy in Australia. International Journal for Parasitology 34, 117123.
Cribb, TH (2016) Editorial: the biodiversity of trematodes of fishes. Systematic Parasitology 93, 219221.
Cribb, TH, Bott, NJ, Bray, RA, McNamara, MKA, Miller, TL, Nolan, MJ and Cutmore, SC (2014) Trematodes of the Great Barrier Reef: emerging patterns of diversity and richness in coral reef fishes. International Journal for Parasitology 44, 929939.
Cribb, TH, Bray, RA, Diaz, PE, Huston, DC, Kudlai, O, Martin, SB, Yong, RQ-Y and Cutmore, SC (2016) Trematodes of fishes of the Indo-west Pacific: told and untold richness. Systematic Parasitology 93, 237247.
Dobson, A, Lafferty, KD, Kuris, AM, Hechinger, RF and Jetz, W (2008) Homage to Linnaeus: how many parasites? How many hosts? Proceedings of the National Academy of Sciences of the USA 105, 1148211489.
Dormann, CF, McPherson, JM, Araujo, MB, Bivand, R, Bolliger, J, Carl, G, Davies, RG, Hirzel, A, Jetz, W, Kissling, WD, Kühn, I, Ohlemüller, R, Peres-Neto, PR, Reineking, B, Schröder, B, Schurr, FM and Wilson, R (2007) Methods to account for spatial autocorrelation in the analysis of species distributional data: a review. Ecography 30, 609628.
Gaston, K. J. (1996). Spatial covariance in the species richness of higher taxa. In Hochberg, M. E., Clobert, J. and Barbault, R. (eds), Aspects of the Genesis and Maintenance of Biological Diversity. Oxford, UK: Oxford University Press, pp. 221242.
Grenyer, R, Orme, CD, Jackson, SF, Thomas, GH, Davies, RG, Davies, TJ, Jones, KE, Olson, VA, Ridgely, RS, Rasmussen, PC, Ding, T-S, Bennett, PM, Blackburn, TM, Gaston, KJ, Gittleman, JL and Owens, IPF (2006) Global distribution and conservation of rare and threatened vertebrates. Nature 444, 9396.
Heino, J (2002) Concordance of species richness patterns among multiple freshwater taxa: a regional perspective. Biodiversity and Conservation 11, 137147.
Jones, KE, Patel, NG, Levy, MA, Storeygard, A, Balk, D, Gittleman, JL and Daszak, P (2008) Global trends in emerging infectious diseases. Nature 451, 990993.
Jorge, F and Poulin, R (2018) Poor geographical match between the distributions of host diversity and parasite discovery effort. Proceedings of the Royal Society B 285, 20180072.
Justine, J-L, Beveridge, I, Boxshall, GA, Bray, RA, Moravec, F and Whittington, ID (2010) An annotated list of fish parasites (Copepoda, Monogenea, Digenea, Cestoda and Nematoda) collected from emperors and emperor bream (Lethrinidae) in New Caledonia further highlights parasite biodiversity estimates on coral reef fish. Zootaxa 269, 140.
Justine, J-L, Beveridge, I, Boxshall, GA, Bray, RA, Miller, TL, Moravec, F, Trilles, J-P and Whittington, ID (2012) An annotated list of fish parasites (Isopoda, Copepoda, Monogenea, Digenea, Cestoda, Nematoda) collected from snappers and bream (Lutjanidae, Nemipteridae, Caesionidae) in New Caledonia confirms high parasite biodiversity on coral reef fish. Aquatic Biosystems 8, 22.
Keitt, TH, Bjørnstad, ON, Dixson, PM and Citron-Pousty, S (2002) Accounting for spatial pattern when modeling organism-environment interactions. Ecography 25, 616625.
Krasnov, BR, Mouillot, D, Khokhlova, IS, Shenbrot, GI and Poulin, R (2005) Covariance in species diversity and facilitation among non-interactive parasite taxa: all against the host. Parasitology 131, 557568.
Legendre, P. and Legendre, L. (1998). Numerical Ecology, 2nd Edn. Amsterdam: Elsevier.
O'Hara, RB and Kotze, DJ (2010) Do not log-transform count data. Methods in Ecology and Evolution 1, 118122.
Pearson, DL, Hamilton, AL and Erwin, TL (2011) Recovery plan for the endangered taxonomy profession. BioScience 61, 5863.
Pebesma, E. J. and Bivand, R. S. (2005). Classes and methods for spatial data in R. R News 5 (2). Available at
Pérez-Ponce de León, G and Choudhury, A (2010) Parasite inventories and DNA-based taxonomy: lessons from helminths of freshwater fishes in a megadiverse country. Journal of Parasitology 96, 236244.
Poulin, R (2014) Parasite biodiversity revisited: frontiers and constraints. International Journal for Parasitology 44, 581589.
Poulin, R. and Morand, S. (2004). Parasite Biodiversity. Washington, DC: Smithsonian Institution Press.
Poulin, R and Presswell, B (2016) Taxonomic quality of species descriptions varies over time and with the number of authors, but unevenly among parasite taxa. Systematic Biology 65, 11071116.
Prendergast, JR and Eversham, BC (1997) Species richness covariance in higher taxa: empirical tests of the biodiversity indicator concept. Ecography 20, 210216.
Quiroz-Martinez, B and Salgado-Maldonado, G (2013) Patterns of distribution of the helminth parasites of freshwater fishes of Mexico. PLoS ONE 8, e54787.
R Core Team (2017). R: A Language and Environment for Statistical Computing. Vienna, Austria: R Foundation for Statistical Computing. Available at
Smith, KF (2009) Global pathogen distributions: a win-win for disease ecology and biogeography. EcoHealth 6, 479480.
Stephens, PR, Altizer, S, Smith, KF, Aguirre, AA, Brown, JH, Budischak, SA, Byers, JE, Dallas, TA, Davies, TJ, Drake, JM, Ezenwa, VO, Farrell, MJ, Gittleman, JL, Han, BA, Huang, S, Hutchinson, RA, Johnson, P, Nunn, CL, Onstad, D, Park, A, Vazquez-Prokopec, GM, Schmidt, JP and Poulin, R (2016) The macroecology of infectious diseases: a new perspective on global-scale drivers of pathogen distributions and impacts. Ecology Letters 19, 11591171.
Venables, W. N. and Ripley, B. D. (2002). Modern Applied Statistics with S, 4th Edn. New York: Springer.
Vilela, B and Villalobos, F (2015) Letsr: a new R package for data handling and analysis in macroecology. Methods in Ecology and Evolution 6, 12291234.
Waeber, PO, Gardner, CJ, Lourenço, WR and Wilmé, L (2017) On specimen killing in the era of conservation crisis: a quantitative case for modernizing taxonomy and biodiversity inventories. PLoS ONE 12, e0183903.
Wolters, V, Bengtsson, J and Zaitsev, AS (2006) Relationship among the species richness of different taxa. Ecology 87, 18861895.
Zuur, AF, Leno, EN and Elphick, CS (2010) A protocol for data exploration to avoid common statistical problems. Methods in Ecology and Evolution 1, 314.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

  • ISSN: 0031-1820
  • EISSN: 1469-8161
  • URL: /core/journals/parasitology
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed