Svenska Spindlar: The Foundation of Modern Spider Nomenclature
In 1757, the Swedish arachnologist and entomologist Carl Alexander Clerck published a groundbreaking work in Stockholm titled Svenska Spindlar (or Aranei Svecici in Latin). This publication served as the first comprehensive study of Swedish spiders and stands as one of the earliest regional monographs of any animal group in history.
The full title of the work, Svenska Spindlar uti sina hufvud-slägter indelte samt under några och sextio särskildte arter beskrefne och med illuminerade figurer uplyste, translates to "Swedish spiders into their main genera separated, and as sixty and a few particular species described and with illuminated figures illustrated." The volume consisted of 162 pages of text—including eight unpaginated pages—and featured six detailed color plates.
Key Facts
- Author: Carl Alexander Clerck.
- Publication Year: 1757.
- Scope: Detailed descriptions of 67 Swedish spider species.
- Innovation: First consistent application of binomial nomenclature in a zoological work.
- Taxonomic Status: The only pre-Linnaean source recognized as a taxonomic authority for animal names.
Scientific Methodology and Presentation
Clerck's approach to arachnology was remarkably precise for the 18th century. In the final chapter of the second part, he established a strict definition of a "spider." He defined them as animals possessing eight eyes and a body divided into a prosoma (the front section) and an opisthosoma (the rear section). By using this definition, he explicitly excluded Opiliones (harvestmen), which possess only two eyes and a broadly joined body structure, as well as other arachnid groups.
For classification, Clerck utilized a single generic name, Araneus, paired with a one-word specific name. Each entry in the Swedish text included the Latin scientific name, the exact dates the specimens were collected, and meticulous descriptions of the legs, eyes, and body. He also documented the morphological differences between sexes. To complement the text, the volume included highly accurate drawings printed on colored copper plates.
Impact on Zoological Nomenclature
The significance of Svenska Spindlar lies in its use of binomial nomenclature—the system of naming species using two parts (genus and species). While Carl Linnaeus had introduced this system for plants in 1753 (Species Plantarum) and later for animals in 1758 (Systema Naturae), Clerck applied it to spiders a year before Linnaeus's animal classification became the standard.
Because of the thoroughness of Clerck's work, his names were adopted by Linnaeus in 1758 with only minor changes. This created a complex historical debate regarding priority. For a time, the International Commission on Zoological Nomenclature (ICZN) suggested the date 1758 should be used for Clerck's names, leading to confusion over whether Linnaeus's Aranea or Clerck's Araneus held priority.
Ultimately, the ICZN clarified that Clerck's 1757 work is a valid taxonomic authority. This means that in cases of conflict, the spelling used by Clerck takes priority over that of Linnaeus. Consequently, Clerck's spiders are the first animals in modern zoology to receive available scientific names under the Linnaean system.
Summary of the Work
| Feature | Details |
|---|---|
| Total Species Described | 67 |
| Primary Genus Used | Araneus |
| Language | Swedish with Latin translations |
| Illustrations | 6 colored copper plates |
| Key Contribution | First zoological use of binomial nomenclature |
Species Cataloged by Chapter
Clerck organized his 67 species into thematic chapters, which align with modern families as follows:
- Chapter 2: Araneidae and Tetragnathidae (e.g., Araneus diadematus).
- Chapter 3: Theridiidae, Nesticidae, and Linyphiidae (e.g., Araneus castaneus).
- Chapter 4: Agelenidae and Clubionidae (e.g., Araneus labyrinthicus).
- Chapter 5: Lycosidae and Pisauridae (e.g., Araneus mirabilis).
- Chapter 6: Salticidae (e.g., Araneus scenicus).
- Chapter 7: Thomisidae, Philodromidae, and Sparassidae (e.g., Araneus vatius).
- Chapter 8: Cybaeidae (e.g., Araneus aquaticus).
Frequently Asked Questions
Why is Svenska Spindlar important to science?
It is the only work published before Linnaeus's 1758 Systema Naturae that is officially recognized as a taxonomic authority for zoological binomial names.
How did Clerck define a spider?
He defined spiders as animals with eight eyes and a distinct separation between the prosoma and opisthosoma, which allowed him to exclude Opiliones and other arachnids.
What is the dispute between the years 1757 and 1758?
While published in 1757, some ICZN rulings previously suggested using 1758 for nomenclature dates. This caused confusion regarding whether Clerck or Linnaeus had priority, though it is now settled that Clerck's names take precedence.
Did Clerck use different genus names for different spiders?
No, Clerck used the single generic name Araneus for all the spider species he described, distinguishing them only by their specific names.
How were the spiders illustrated in the book?
The species were depicted using impressively accurate drawings printed on six colored copper plates bound at the end of the volume.