Accepted by G. Ruiz: 5 Dec. 2018; published: 18 Jan. 2019
ISSN 1175-5326 (print edition)
Copyright © 2019 Magnolia Press
Zootaxa 4545 (3): 444
How not to delimit taxa: a critique on a recently proposed “pragmatic
classification” of jumping spiders (Arthropoda: Arachnida: Araneae: Salticidae)
, THEO BLICK
, ANTONIO D. BRESCOVIT
, MARIA CHATZAKI
, DANIEL GLOOR
, CHARLES R. HADDAD
, MARK S. HARVEY
, PETER JÄGER
YURI M. MARUSIK
, HIROTSUGU ONO
, CRISTINA A. RHEIMS
Natural History Museum Bern, Switzerland
Institute of Ecology and Evolution, University of Bern, Switzerland
Laboratório Especial de Coleções Zoológicas, Instituto Butantan, São Paulo, SP, Brazil
Department of Molecular Biology and Genetics, Democritus University of Thrace, Alexandroupolis, Greece
Department of Arachnology, Zentrum für Naturkunde, Universität Hamburg, Germany
Department of Zoology & Entomology, University of the Free State, Bloemfontein, South Africa
Department of Terrestrial Zoology, Western Australian Museum, Australia. Adjunct: School of Biological Sciences, University of
Western Australia, Australia
Arachnology, Senckenberg Research Institute, Frankfurt am Main, Germany
Institute for Biological Problems of the North, Magadan, Russia
Department of Zoology, National Museum of Nature and Science, Japan
Corresponding author. E-mail: firstname.lastname@example.org
Modern taxonomy and systematics profit from an invaluable tool that has been developed in the course of more than a
century by intense discussions and negotiations of generations of zoologists and palaeontologists: The International Code
of Zoological Nomenclature (ICZN 1999, 2012). The main goal of the Code is “to promote stability and universality in
the scientific names of animals and to ensure that the name of each taxon is unique and distinct” (Melville 1995, ICZN
1999: 2). The provisions of the Code are generally accepted and thoroughly applied by the scientific community.
Exceptions, such as the one described below, are very rare.
The recent biodiversity crisis (e.g. Barnosky et al. 2011) and the insufficient number of taxonomists (e.g. Bacher
2012) lead to various approaches for improving the taxonomic procedure and for speeding up taxonomic progress
intended to describe the world’s species richness before large parts of it have become extinct, and to provide science-
based strategies against the loss of biodiversity. The usage of a variety of methods, including textual differential
diagnoses and descriptions, morphometrics, accurate illustrations, stacked photographs, SEM pictures and Micro-CT
representations of taxonomically relevant structures, as well as a wide range of molecular data, has become good practice
in taxonomy and systematics. As a consequence, modern taxon descriptions are much more comprehensive than in
earlier times. However, sometimes the amplification of various methods and techniques may cause complications rather
than enhancing good taxonomic practice. This may especially be true in cases where these tools are seen as exchangeable
rather than complementary, and newer approaches completely replace the more time-consuming textual descriptions or
pencil- and ink drawings (e.g., Coleman 2006; cf. Jäger 2016).
Recently, a new approach, termed “pragmatic classification” was suggested by Prószyński (2017a) in the taxonomy
of salticid spiders. Prószyński has an enormous reputation in this field, and Salticidae is the most species-rich family of
spiders, currently comprising more than 6100 extant and extinct species worldwide, representing ca. 13% of the global
spider diversity (World Spider Catalog 2018). They inhabit almost all types of land ecosystems and are therefore a target
group for describing, classifying and cataloguing the world’s terrestrial biodiversity. Prószyński considers word
descriptions and diagnoses of salticid spider taxa as mostly superfluous and even misleading. In a series of
publications on salticid taxonomy, he stated that the “traditional system of Salticidae (…) is insufficient to accommodate
hundreds of new taxa” (Prószyński 2016a: 4), and therefore, an “alternative classification of Salticidae” (Prószyński
2017a: 3) is needed. He based his approach on a large-scale “synthetic comparison of main diagnostic drawings”
(Prószyński 2016a: 5), and he proposed to select diagnostic characters of genera and species “by precise drawings of
palps, epigyne, spermathecae and ducts (…) and dismissal of translation of these drawings into words”. Because such a
Zootaxa 4545 (3) © 2019 Magnolia Press ·
HOW NOT TO DELIMIT TAXA: "PRAGMATIC CLASSIFICATION"
set of drawings should not need further explanation, “dutifully made tedious descriptions of external appearances and
measurements of body parts (…) are almost useless” while, in contrast, “graphic definitions appear unequivocal”
(Prószyński 2017b: 37). He underlined his view several times as the “translation of appearance of characters into words
is too imprecise and often misleading” (Prószyński 2017a: 9), “the traditional way of documenting species by
descriptions with words and by routine measurements is particularly ineffective”, “lengthy description could be replaced
by color photographs of 3-4 key aspects of spider body appearance” (Prószyński 2018: 132−133), and so on. He further
claims that his system is provisional and intended purely for identification purposes. This system should exist in “parallel
to more theoretical system of affinities and phylogeny” (Prószyński 2017a: 4). Later (Prószyński 2018: 176), he extended
the usage of “pragmatic classification” to help “explain presumable relationships between biological entities, such as
species and genera”, while further stating that his classification “does not accept changes based on supposed gene
differences if they are not congruent with morphological premises” (Prószyński 2018: 177).
Based on his “pragmatic classification” approach, Prószyński created numerous new salticid genera in a series of
papers (e.g., Prószyński 2016a, 2018). This dynamic intervention into taxonomic practice has caused intense discussions
of the World Spider Catalog editorial team (most of them are co-authors of this contribution) with taxonomists from all
over the world, including Prószyński himself. Thus, we address some problems with “pragmatic classification” that seem
to us worthy of clarification.
(1) Disregard of ICZN rules. First of all, ICZN article 13.1.1 clearly states that, in order to be available, a new
name published after 1930 must “be accompanied by a description or definition that states in words characters that are
purported to differentiate the taxon” (emphasis by us; ICZN 1999, 2012). Therefore, a “pragmatic classification”, with its
disregard of textual descriptions and especially diagnoses, violates this article, or at least its meaning: There must be
evidence justifying a taxon, and this evidence must be explained. If it is not, this is an appeal to authority, not to
evidence. Furthermore, Prószyński’s (2017b: 37) claim that “graphic definitions appear unequivocal” is not supported by
facts — a glimpse on the different diagnostic figures for many European spider species in the database “Spiders of
Europe” (Nentwig et al. 2018) demonstrates the opposite. Good scientific drawings are always abstractions of reality,
underlining the relevant structures and neglecting the irrelevant ones. They do not only vary by their unique artistry, but
their interpretation may be subject to “the eye of the beholder”. Therefore, comparative illustrations (as important as they
are) cannot be regarded as a scientifically sound substitute for textual diagnoses.
(2) Disregard of the need to explain evidence. With its refusal to explain the evidence that should be found in
illustrations, Prószyński leaves it up to the reader to find this evidence by him- or herself. Therefore, the conclusions
expressed in a “pragmatic classification” are literally unjustified, and we suspect that in many cases they are likely false.
We do not know of any other field of science where simply presenting any evidence without explaining it, would be
accepted by the community.
(3) Descriptive taxonomy vs systematics (an old story). With “pragmatic classification”, an explicit classification
is created in parallel with the one that aims to reflect the taxa’s phylogeny. This reminds us of the long-lasting “Hennig vs
Mayr” dispute, but this discussion was already decided decades ago in favour of the former. There is only a single
objective base for a classification in systematics, and this is the unique process of phylogeny — thus, one could even
discuss a violation of the basic principle of objectivity in natural science by Prószyński’s “pragmatic classification”. The
creation of a parallel classification that disregards the information from molecular (and indeed, also morphological;
Maddison & Hedin 2003; Maddison 2015) phylogenies is even more bizarre, as “pragmatic classification” should also
shed light on the relationships of species and genera (Prószyński 2018). This procedure seems unacceptable, given the
important progress in salticid phylogeny in recent years, exhibited in a series of excellent contributions summarized by
Maddison (2015), which led to a comprehensive salticid classification, with placements for 96% of fossil and extant
genera. With the “pragmatic classification” approach, a severely retrograde scientific step has occurred, and confusion
and chaos in future salticid systematics seem to become an unavoidable outcome if such a system would be implemented
or widely accepted.
(4) Disregard of modern scientific methods. Prószyński (2017b) also rejects new taxonomic methods other than
molecular ones, in particular morphometrics (citations above). We cannot see any rational foundation for this, as modern
morphometrics are successfully applied in numerous taxonomic groups (Zelditch et al. 2012), especially in arthropods.
The enormous power of measurements and especially of ratios in connection with multivariate statistical methods has
been shown convincingly (Baur & Leuenberger 2011). Morphometrics may even provide a satisfying “loophole” in
diagnosing “cryptic” species by eye (e.g., Baur et al. 2014), that up till now could only be characterized by molecules (a
drawback that Prószyński himself laments).
(5) Suprageneric names ending with -INES. Prószyński (2017a: 9) created numerous suprageneric names ending
with “-INES” as “informal GROUPS OF GENERA” written entirely in capital letters to indicate that these are neither
subfamilial nor other names ruled by the Code. In spite of this, Prószyński (2017a) attributed to these informal names his
authorship with 2016 as year of publication, which does not correspond to the year of a valid publication concerning this
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· Zootaxa 4545 (3) © 2019 Magnolia Press
matter, but rather to his webpage (Prószyński 2016b). Examples for such names are ASTIAINES Prószyński, 2016
(compare Astieae Simon, 1901), CHRYSILLINES Prószyński, 2016 (compare Chrysilleae Simon, 1901), PELLENINES
Prószyński, 2016 (compare Pelleninae Petrunkevitch, 1928), and so on. In contrast to his own publication (Prószyński
2017a), he uses the heading “subfamilies” at his webpage (Prószyński 2016b: Part I). It is obvious that the creation of
these names brings nothing but chaos in salticid systematics, and they should therefore be ignored by the community, or
at best, be considered as incorrect spelling of the respective available names. Furthermore, we do not understand how a
journal mostly dedicated to taxonomy and systematics (in this case “Ecologica Montenegrina”, https://www.biotaxa.org/
em) can accept this type of papers, claiming to have passed them through a peer-reviewing process. Many of the basic
errors highlighted above would have been pointed out by even a moderately competent reviewer familiar with basic
salticid systematics and taxonomic principles. In our view, this is nothing but scientific malpractice.
In order not to be misunderstood, we want to point out that we consider Prószyński’s lifework as truly exceptional
and feel a deep respect for it. But we must conclude that his “pragmatic classification” approach brings only limited
insights to salticid taxonomy and systematics. The editorial team members of the World Spider Catalog therefore already
did and will make accessible all taxonomic and nomenclatural information from the cited papers (this is indeed the
purpose of the Catalog; Nentwig et al. 2015; World Spider Catalog 2018), but we will reserve the right not to implement
all of the suggested changes for the structure of the Catalog to promote taxonomic stability in the Salticidae.
Bacher, S. (2012) Still not enough taxonomists. Trends in Ecology and Evolution, 27, 65–66.
Barnosky, A.D., Matzke, N., Tom iya , S., Wo gan , G.O.U., Swartz, B., Quental, T.B., Marshall, C., McGuire, J.L., Lindsey, E.L.,
Maguire, K.C., Mersey, B. & Ferrer, E.A. (2011) Has the earth’s sixth mass extinction already arrived? Nature, 471, 51–57.
Baur, H., Kranz-Baltensperger, Y., Cruaud, A., Rasplus, J.-Y., Timokhov, A.V. & Gokhman, V.E. (2014) Morphometric analysis and
taxonomic revision of Anisopteromalus Ruschka (Hymenoptera: Chalcidoidea: Pteromalidae) — an integrative approach.
Systematic Entomology, 39, 691–709.
Baur, H. & Leuenberger, C. (2011) Analysis of ratios in multivariate morphometry. Systematic Biology, 60, 813–825.
Coleman, C.O. (2006) Substituting time-consuming pencil drawings in arthropod taxonomy using stacks of digital photographs.
Zootaxa, 1360, 61–68.
ICZN [International Commission on Zoological Nomenclature] (1999) International Code of Zoological Nomenclature. Fourth
edition. International Trust for Zoological Nomenclature, London, 126 pp.
ICZN (2012) International Code of Zoological Nomenclature. 4
Edition. [Incorporating Declaration 44, amendments of Article
74.7.3, with effect from 31 December 1999 and the Amendment on e-publication, amendments to Articles 8, 9, 10, 21 and 78, with
effect from 1 January 2012]. Available from: http://www.nhm.ac.uk/hosted-sites/iczn/code (accessed 31 May 2018)
Jäger, P. (2016) A plea for taxonomic drawings and against pure photo-taxonomy. Indian Journal of Arachnology, 5 (1–2), 61–66.
Maddison, W.P. (2015) A phylogenetic classification of jumping spiders (Araneae: Salticidae). Journal of Arachnology, 43, 231–292.
Maddison, W.P. & Hedin, M.C. (2003) Jumping spider phylogeny (Araneae: Salticidae). Invertebrate Systematics, 17, 529–549.
Melville, R.V. (1995) Towards stability in the names of animals. A history of the International Commission on Zoological
Nomenclature 1895–1995. International Trust of Zoological Nomenclature, London, 92 pp.
Nentwig, W., Gloor, D. & Kropf, C. (2015) Spider taxonomists catch data on web. Nature, 528, 479.
Nentwig, W., Blick, T., Gloor, D., Hänggi, A. & Kropf, C. (2018) Spiders of Europe. Version 05.2018. Available from: http://
www.araneae.nmbe.ch (accessed 31 May 2018)
Prószyński, J. (2016a) Delimitation and description of 19 new genera, a subgenus and a species of Salticidae (Araneae) of the world.
Ecologica Montenegrina, 7, 4–32.
Prószyński, J. (2016b) Monograph of Salticidae (Araneae) of the world 1995–2015. Part 1 & 2. Available from: http://
www.peckhamia.com/salticidae/Subfamilies & http://www.peckhamia.com/salticidae (accessed 31 May 2018)
Prószyński, J. (2017a) Pragmatic classification of the world's Salticidae (Araneae). Ecologica Montenegrina, 12, 1–133.
Prószyński, J. (2017b) Revision of the genus Sitticus Simon, 1901 s. l. (Araneae: Salticidae). Ecologica Montenegrina, 10, 35–50.
Prószyński, J. (2018) Review of genera Evarcha and Nigorella, with comments on Emertonius, Padilothorax [sic], Stagetillus, and
description of five new genera and two new species (Araneae: Salticidae). Ecologica Montenegrina, 16, 130–179.
World Spider Catalog (2018) World Spider Catalog. Version 19.0. Natural History Museum Bern. Available from: http://wsc.nmbe.ch
(accessed 31 May 2018)
Zelditch, M.L., Swiderski, D. & Sheets, H.D. (2012) Geometric Morphometrics for Biologists: A Primer. Second Edition. Elsevier
Academic Press, London, 488 pp.