Interdisciplinarity to reconstruct historical introductions: solving the status of cryptogenic crayfish

Abstract

Anciently introduced species can be confounded with native species because introduction pre-dates the first species inventories or because of the loss of the collective memory of the introductions. The term 'cryptogenic species' denotes species of unknown or unclear status (native versus non-native) in a given territory, and disciplinary approaches are often insufficient for solving their true status. Here, we follow an integrative, multidisciplinary approach to solve the status of a cryptogenic species, proposing that building on evidence from multiple disciplines can produce robust and clarifying insights. We undertook an exhaustive review of information on a putatively native crayfish (Austropotamobius italicus) in Spain. The reviewed information included taxonomy, genetics and phylogeography, history, archaeology, linguistics, biogeography, ecology, symbiotic organisms and even gastronomy and pharmacy. The knowledge produced by different scientific disciplines converges to indicate that A. italicus is a non-native species in Spain. Historical documents even identify the first introduction event: crayfish were shipped from Italy to Spain in 1588 as a diplomatic gift from Francesco I de' Medici to King Philip II of Spain. Previous discussions on the status of A. italicus focussed on inconclusive and often confusing genetic results and excluded the rich and clarifying evidence available from other approaches and disciplines. Interdisciplinarity is an often-invoked but rarely implemented practice in an academic environment that increasingly promotes narrowfocussed specialization. Our review shows that the integration of disciplines can surpass disciplinary approaches in solving scientific controversies. Our results have straightforward implications for strategies to conserve biological diversity in Spain and Europe, urging a debate on the appropriateness of devoting conservation efforts to nonnative species.

Update of genetic information for the white-clawed crayfish in Spain, with new insights into its population genetics and origin

“…It has been recently suggested (Clavero and Villero 2013;Clavero et al 2015) that this species was not present in the Iberian peninsula before the seventeenth century, a limit based on the absence of any reference to the species in the Relaciones topográficas survey ordered by Philip II (henceforth Relaciones) which was undertaken between 1556 and 1598 (Clavero and Villero 2013). The first written document known to the latter authors that mentions crayfish in Spain dates from 1775.…”

Historical data: Hidden in the past

“…The documents showed that Spain's King Philip II had asked a member of his court to arrange for crayfish to be brought from Italy, and that the animals were shipped in 1588 (ref. 6) .…”

“…However, catch rates from a 1905 fisherman's book were higher 1 , suggesting that the author might have described only his best trips. Similarly, Clavero's team backed up its finding 6 from the Spanishcourt letters with evidence from fields such as archaeology, linguistics, genetics and ecology.…”

Multiple, solid evidence support that Austropotamobius italicus is not native to Spain

“…First, we point out that the mono-disciplinary approach followed by Matallanas et al (2016) is 17 much weaker than the transdisciplinary approach used and advocated by Clavero et al (2016).…”