Testing species boundaries of an unknown Dolomedes (Araneae, Dolomedidae) morphospecies from isolated islands
Abstract
Raft spiders, family Dolomedidae, represent a group of spiders with 7 genera distributed near globally well known for a semi-aquatic lifestyle. One of the iconic genera representing such a unique lifestyle is the largest and diverse dolomedid genus Dolomedes. Although Dolomedes is well surveyed in parts of its distribution, its diversity in the tropics remains largely unknown, such as the western Indian Ocean region with most of the islands unsurveyed. Recent expeditions to Madagascar and La Réunion Island discovered a series of specimens that appear to belong to an unknown morphospecies of Dolomedes, exhibiting varying degrees of differences in the diagnostic characteristics. To further test and define their species boundaries, we include molecular evidence followed by species delimitation analyses. Our findings indicate that specimens from both islands are conspecific. Consequently, we introduce a new species to science, Dolomedes reuniascar sp. nov., providing detailed illustrations, descriptions of its variations and ecological characteristics. Based on our observations and existing literature, we speculate that the presence of this species on the two isolated islands could be attributed to either highly efficient dispersal abilities, such as ballooning of spiderlings, or human-mediated introduction events.
References
Ali J.R. & Aitchison J.C. 2008. Gondwana to Asia: plate tectonics, paleogeography and the biological connectivity of the Indian sub-continent from the Middle Jurassic through latest Eocene (166–35 Ma). Earth-Science Reviews 88 (3–4):145–166. https://doi.org/10.1016/j.earscirev.2008.01.007
Baba Y., Watari Y, Nishi M., Sasaki T. 2019. Notes on the feeding habits of the Okinawan fishing spider, Dolomedes orion (Araneae: Pisauridae), in the southwestern islands of Japan. Journal of Arachnology 47 (1): 154–158. https://doi.org/10.1636/0161-8202-47.1.154
Bell J.R., Bohan D.A., Shaw E.M. & Weyman G.S. 2005. Ballooning dispersal using silk: world fauna, phylogenies, genetics and models. Bulletin of Entomological Research 95 (2): 69–114. https://doi.org/10.1079/ber2004350
Blandin P. 1979. Études sur les Pisauridae afrícaines XI. Genres peu connus ou nouveaux des Iles Canaries, du Continent africaín et de Madagascar. Revue Zoologique Africaine 93: 347–375. https://doi.org/10.5962/bhl.part.76005
Bond J.E., Godwin R.L., Colby J.D., Newton L.G., Zahnle X.J., Agnarsson I., Hamilton C.A. & Kuntner M. 2022. Improving taxonomic practices and enhancing its extensibility – an example from araneology. Diversity 14 (1): 5. https://doi.org/10.3390/d14010005
Bosselaers J. 2010. A new species of Heser Tuneva, 2005 (Araneae, Gnaphosidae) from the south of India. ZooKeys 73: 1–11. https://doi.org/10.3897/zookeys.73.837
Carico J.E. 1973. The Nearctic species of the genus Dolomedes (Araneae: Pisauridae). Bulletin of the Museum of Comparative Zoology 144: 435–488.
Casquet J. 2011. L’arachnofaune de La Réunion Check-list des espèces. In: Casquet J. 2012. Hasard, déterminisme et édification des communautés écologiques insulaires: le cas des araignées d’Hawaï et des îles de l’Océan Indien. PhD thesis, University of Toulouse 3 Paul Sabatier (UT3 Paul Sabatier), France.
Casquet J. 2012. Hasard, déterminisme et édification des communautés écologiques insulaires: le cas des araignées d’Hawaï et des îles de l’Océan Indien. PhD thesis, University of Toulouse 3 Paul Sabatier (UT3 Paul Sabatier), France.
Cazanove G. 2022. L’aranéofaune de La Réunion: check-list révisée. Bulletin de l’Association Française d’Arachnologie 8: 4–29.
Chamberlin R.V. 1924. Descriptions of new American and Chinese spiders, with notes on other Chinese species. Proceedings of the United States National Museum 63 (13): 1–38. https://doi.org/10.5479/si.00963801.63-2481.1
Clerck C. 1757. Aranei Svecici. Svenska spindlar, uti sina hufvud-slågter indelte samt under några och sextio särskildte arter beskrefne och med illuminerade figurer uplyste. Laurentius Salvius, Stockholmiae. https://doi.org/10.5962/bhl.title.119890
De Queiroz K. 2005. A unified concept of species and its consequences for the future of taxonomy.Proceedings of the California Academy of Sciences: 196–215.
De Queiroz K. 2007. Species concepts and species delimitation. Systematic Biology 56 (6): 879–886. https://doi.org/10.1080/10635150701701083
Frost C.M., Graham A.K. & Spence J.R. 2013. Abiotic conditions rather than resource availability cues determine aerial dispersal behavior in spiderlings of Dolomedes triton (Araneae: Pisauridae). Canadian Entomologist 145 (1): 29–39. https://doi.org/10.4039/tce.2012.92
Gertsch W.J. 1934. Further notes on American spiders. American Museum Novitates 726: 1–26.
Gillespie R.G., Croom H.B. & Palumbi S.R. 1994. Multiple origins of a spider radiation in Hawaii. Proceedings of the National Academy of Sciences of the United States of America. 91 (6): 2290–2294. https://doi.org/10.1073/pnas.91.6.2290
Goyen, P. 1888. Descriptions of new species of New Zealand Araneae. Transactions and Proceedings of the New Zealand Institute 20: 133–139.
Graham A. 2002. Wetland Spider Diversity and Ecology in Alberta: 4. Mechanisms and Regulation of Ballooning in the Fishing Spider Dolomedes Triton Walckenaer (Araneae: Pisauridae). M.Sc. Thesis. University of Alberta, Edmonton, Alberta, Canada.
Hasselt A.W.M. van. 1882. Araneae. In: Veth, P. J. (ed.) Midden-Sumatra 4.11 A. Reizen en onderzoekingen der Sumatra-expeditie, uitgerust door het aardrijkskundig genootschap, 1877–1879. Brill, Leiden. https://doi.org/10.5962/bhl.title.119451
Hedin M. & Milne M.A. 2023. New species in old mountains: integrative taxonomy reveals ten new species and extensive short-range endemism in Nesticus spiders (Araneae, Nesticidae) from the southern Appalachian Mountains. ZooKeys 1145 (4):1–130. https://doi.org/10.3897/zookeys.1145.96724
Huelsenbeck J.P. & Ronquist F. 2001. MRBAYES: Bayesian inference of phylogenetic trees. Bioinformatics Applications Note 17 (8): 754–755. https://doi.org/10.1093/bioinformatics/17.8.754
Jukes T.H. & Cantor C.R. 1969. Evolution of protein Molecules. In: Munro, H.N. (ed.), Mammalian Protein Metabolism: 21–132. Academic Press, New York.
Katoh K., Rozewicki J. & Yamada K.D. 2019. MAFFT online service: multiple sequence alignment, interactive sequence choice and visualization. Briefings in Bioinformatics 20 (4): 1160–1166. https://doi.org/10.1093/bib/bbx108
Kimura M. 1980. A simple method for estimating evolutionary rates of base substitutions through comparative studies of nucleotide sequences. Journal of Molecular Evolution 16: 111–120. https://doi.org/10.1007/BF01731581
Koch, L.. 1876. Die Arachniden Australiens, nach der Natur beschrieben und abgebildet. Bauer & Raspe, Nürnberg. https://doi.org/10.5962/bhl.title.121660
Koch L. 1878. Die Arachniden Australiens, nach der Natur beschrieben und abgebildet, Lieferung 22–23: 969–1044. Bauer & Raspe, Nürnberg. https://doi.org/10.5962/bhl.title.121660
Lattimore V.L., Vink C., Paterson A. & Cruickshank R. 2011. Unidirectional introgression within the genus Dolomedes (Araneae: Pisauridae) in southern New Zealand. Invertebrate Systematics 25 (1): 70–79. https://doi.org/10.1071/IS11001
Latreille P.A. 1804. Tableau méthodique des insectes. Nouveau Dictionnaire d’Histoire naturelle Paris 24: 129–295.
Ledoux J.C. 2004. Araignées de l’île de La Réunion. I. Hahniidae, Ctenidae, Thomisidae et Clubionidae (Araneae). Revue Arachnologique 14: 159–191.
Ledoux, J.C. 2007. Araignées de l’île de La Réunion. 2. Salticidae. Revue Arachnologique 17: 9–34.
Maddison W.P. & Maddison D.R. 2018. Mesquite: a modular system for evolutionary analysis. Ver. 3.61. Available from https://www.mesquiteproject.org [accessed 05 03 2024]
Menge A. 1866. Preussische Spinnen. Erste Abtheilung. Schriften der Naturforschenden Gesellschaft in Danzig (N.F.) 1: 1–152.
Miller M.A., Pfeiffer W. & Schwartz T. 2010. Creating the CIPRES Science Gateway for Inference of large phylogenetic trees. In: Proceedings of the Gateway Computing Environments Workshop (GCE): 1–8. IEEE: New Orleans, LA, USA.
Nyffeler M. & Pusey B.J. 2014. Fish predation by semi-aquatic spiders: a global pattern. PLoS ONE 9 (6): e99459. https://doi.org/10.1371/journal.pone.0099459
Posada D. 2008. jModelTest: phylogenetic model averaging. Molecular Biology and Evolution 25 (7): 1253–1256. https://doi.org/10.1093/molbev/msn083
Puillandre N., Brouillet S. & Achaz G. 2021. ASAP: assemble species by automatic partitioning. Molecular Ecology Resources 21 (2): 609–620. https://doi.org/10.1111/1755-0998.13281
QGIS.org 2023. QGIS Geographic Information System. QGIS Association. Available from https://www.qgis.org [accessed 21 08 2023]
Raven R.J. & Hebron W. 2018. A review of the water spider family Pisauridae in Australia and New Caledonia with descriptions of four new genera and 23 new species. Memoirs of the Queensland Museum, Nature 60: 233–381. https://doi.org/10.17082/j.2204-1478.60.2018.2017-06
Roewer C.F. 1955. Araneae Lycosaeformia I. (Agelenidae, Hahniidae, Pisauridae) mit Berücksichtigung aller Arten der äthiopischen Region. Exploration du Parc national de l’Upemba, Mission G. F. de Witte 30: 1–420.
Sanmartín I. & Ronquist F. 2004. Southern hemisphere biogeography inferred by event-based models: plant versus animal patterns. Systematic Biology 53 (2): 216–243. https://doi.org/10.1080/10635150490423430
Sierwald P. 1997. Phylogenetic analysis of pisaurine nursery web spiders, with revisions of Tetragonophthalma and Perenethis (Araneae, Lycosoidea, Pisauridae). Journal of Arachnology 25: 361–407.
Silva E.L.C. da & Griswold C.E. 2013. A new species of Dolomedes Latreille, 1804 (Araneae: Lycosoidea: Pisauridae) from Madagascar. Zootaxa 3691 (4): 461–466. https://doi.org/10.11646/zootaxa.3691.4.5
Simon E. 1876. Les arachnides de France. Tome troisième. Roret, Paris.
Simon E. 1890. Études arachnologiques. 22e Mémoire. XXXIV. Etude sur les arachnides de l’Yemen. Annales de la Société entomologique de France (6) 10: 77–124.
Stamatakis A. 2014. RAxML ver. 8: A tool for phylogenetic analysis and post-analysis of large phylogenies. Bioinformatics 30 (9): 1312–1313. https://doi.org/10.1093/bioinformatics/btu033
Strand E. 1906. Sumatra und Neu-Guinea Spinnen des naturhistorischen Museums zu Wiesbaden. Jahrbücher des Nassauischen Vereins für Naturkunde 59: 257–278.
Strand E. 1907. Diagnosen neuer Spinnen aus Madagaskar und Sansibar. Zoologischer Anzeiger 31: 725–748.
Sukumaran J. & Holder M.T. 2010. DendroPy: A Python library for phylogenetic computing. Bioinformatics 26 (12): 1569–1571. https://doi.org/10.1093/bioinformatics/btq228
Sukumaran J. & Holder M.T. 2015. SumTrees: Phylogenetic Tree Summarization 4.0.0 (Jan 31 2015). Available from https://github.com/jeetsukumaran/DendroPy. [accessed 18 december 2023]
Suter R.B. 1999. Cheap transport for fishing Spiders (Araneae, Pisauridae): The physics of Sailing on the water Surface. Journal of Arachnology 27 (2): 489–496.
Tanikawa A. 2003. Two new species and two newly recorded species of the spider family Pisauridae (Arachnida: Araneae) from Japan. Acta Arachnologica 52 (1): 35–42. https://doi.org/10.2476/asjaa.52.35
Tanikawa A. & Miyashita T. 2008. A revision of Japanese spiders of the genus Dolomedes (Araneae: Pisauridae) with its phylogeny based on mt-DNA. Acta Arachnologica 57 (1): 19–35. https://doi.org/10.2476/asjaa.57.19
Thebaud C., Warren B.H., Strasberg D. & Cheke A. 2009. Mascarene Islands, Biology. In: Gillespie D.A (ed.). Encyclopedia of islands: 612–619. University of California Press.
Vink C. & Dupérré N. 2010. Pisauridae (Arachnida: Araneae). Fauna of New Zealand 64: 1–60.
Vinson A. 1863. Aranéides des îles de la Réunion, Maurice et Madagascar. Roret, Paris.
Walckenaer C.A. 1837. Histoire naturelle des insectes. Aptères. Tome premier. Roret, Paris.
World Spider Catalog (WSC) 2025. World Spider Catalog. Ver. 26. Natural History Museum Bern. https://doi.org/10.24436/2
Yu K.-P. & Kuntner M. 2024. Discovering unknown Madagascar biodiversity: Integrative taxonomy of raft spiders (Pisauridae: Dolomedes). PeerJ 12: e16781. https://doi.org/10.7717/peerj.16781
Yu K.-P., Cheng R.-C., Haddad C.R., Tanikawa A., Pett B.L., Piacentini L.N., Yip H.Y., Suzuki Y., Henrard A., Painting C.J., Vink C.J., Hebets E.A., Harvey M.S. & Kuntner M. 2025. Systematics and evolutionary history of raft and nursery-web spiders (Araneae: Dolomedidae and Pisauridae). Zoologica Scripta 54: 421–435. https://doi.org/10.1111/zsc.12719
Zhang J.X., Zhu M.S. & Song D.X. 2004. A review of the Chinese nursery-web spiders (Araneae, Pisauridae). Journal of Arachnology 32 (3): 353–417. https://doi.org/10.1636/M02-58
Zhang J., Kapli P., Pavlidis P. & Stamatakis A. 2013. A general species delimitation method with applications to phylogenetic placements. Bioinformatics 29 (22): 2869–2876. https://doi.org/10.1093/bioinformatics/btt499
Copyright (c) 2025 Grégory Cazanove, Yu Kuang-Ping, Brice Derepas, Arnaud Henrard
This work is licensed under a Creative Commons Attribution 4.0 International License.
Creative Commons Copyright Notices
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License (CC BY 4.0) that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are NOT PERMITTED to post their submitted work online (e.g., in institutional repositories or on personal websites) prior to publication, as it may lead to nomenclatural issues.
