Dolomedidae, Simon, 1876

Yu, Kuang-Ping, Cheng, Ren-Chung, Haddad, Charles R., Tanikawa, Akio, Pett, Brogan L., Piacentini, Luis N., Yip, Ho Yin, Suzuki, Yuya, Henrard, Arnaud, Painting, Christina J., Vink, Cor J., Hebets, Eileen A., Harvey, Mark S. & Kuntner, Matjaž, 2025, Systematics and evolutionary history of raft and nursery-web spiders (Araneae: Dolomedidae and Pisauridae), Zoologica Scripta 54 (3), pp. 421-435 : 427-429

4.1 | Dolomedidae : A step towards the redefinition of Pisauridae

We use a well-sampled and robust phylogenomic backbone to support the resurrection of Dolomedidae , Lehtinen's (1967) taxonomic hypothesis that has regained recent attention ( Albo et al., 2017; Hazzi & Hormiga, 2023; Kulkarni et al., 2023). Our phylogenies are consistent with the topologies found by Hazzi and Hormiga (2023) and Kulkarni et al. (2023) that Dolomedes is sister to the clade including Lycosidae , Trechaleidae , and additionally Blandinia . Although several putatively closely related genera of Dolomedes , including Bradystichus Simon, 1884 , Caledomedes Raven & Hebron, 2018 , Mangromedes Raven & Hebron, 2018 , and Tasmomedes Raven & Hebron, 2018 , were not available for inclusion with UCE data, additional evidence from morphological ( Platnick & Forster, 1993; Raven & Hebron, 2018) and molecular ( Kulkarni et al., 2023; Piacentini & Ramírez, 2019) studies both suggest that these genera fit our definition of Dolomedidae rather than Pisauridae . This updated classification of Dolomedidae is formalized in the Taxonomy as it fulfils our classification criteria: Dolomedidae is monophyletic, is well diagnosable, and shows divergences comparable with clade ages of the other families represented in the phylogeny (Figure 4).

The Dolomedes paraphyly hinges on one species, D. karijini , that is recovered as the sister of Ornodolomedes . Considering it is morphologically and ecologically distinct from Ornodolomedes (see Raven & Hebron, 2018), D. karijini could be resolved through an establishment of a new genus for this species group. Although we envision this solution being valid in the future, we refrain from doing so here due to our limited access to Australian species. Based on details of the genitalia, Raven and Hebron (2018) treated D. karijini in the D. albicomus L. Koch, 1867 group with Dolomedes species from Australia and New Caledonia. Considering the incomplete taxon sampling and the current ambiguity of species boundaries within Dolomedes ( Tanikawa & Miyashita, 2008; Vink & Dupérré, 2010; Yu & Kuntner, 2024), it is unclear whether the entire species group, or only D. karijini should be elevated to a new genus. This decision will await future integrative taxonomic work with more Australasian species.

Our taxonomy is only the first step towards a better definition of Pisauridae and its subfamilies. Although our phylogenies reject the classification of Blandinia as a pisaurid, it is unclear whether this monotypic genus can be assigned to another existing family. Considering the conflicting Trechaleidae phylogenies (see Hazzi & Hormiga, 2023; Kulkarni et al., 2023; Piacentini & Ramírez, 2019) and our limited access to many trechaleid lineages, placing Blandinia in Trechaleidae sensu lato would also be unfounded. We therefore avoid creating a new family and hence treat Blandinia as incertae sedis until further evidence becomes available. Our phylogeny also partially rejects the currently used pisaurid subfamilial classifications, Thaumasinae, Thalassinae, and Pisaurinae ( Sierwald, 1990; Simon, 1898a), a problem that awaits more focused systematics and taxonomic efforts.