For more than fifty years, the so-called Iberian crayfish has appeared in Spain’s official catalogs as a vulnerable native species that needs urgent protection.
A new scientific study now argues that this freshwater crustacean is actually an Italian guest that arrived in 1588 to decorate King Philip II’s royal ponds, which puts Spain’s conservation policy in a very uncomfortable spot.
A royal fashion that rewrote river life
The research, led by ecologist Miguel Clavero from the Doñana Biological Station and art historian Alicia Sempere Marín from the University of Murcia, dives into 16th-century archives instead of fishing nets.
The team located more than a dozen documents dated between 1563 and 1588 that detail repeated attempts by Philip II’s court to stock crayfish in the ornamental ponds of the Royal Sites.
Early shipments from Flanders and France apparently failed. Only in early 1588 did a servant of the Grand Duke of Tuscany, Antonio de Ugnano, manage to transport live crayfish all the way to Madrid, earning a reward of 300 ducats, roughly the annual salary of a physician at the time.
The study identifies those animals as the Italian crayfish Austropotamobius fulcisianus. Today, crayfish with the same genetic lineages occupy many Iberian streams and are still widely treated as the “Iberian” species by administrations and management plans.
When a protected species is not really native
Here is where the story collides with modern law. Spain’s Law 42 of 2007 on Natural Heritage and Biodiversity defines an invasive alien species as one that is introduced or established in a natural or semi-natural ecosystem and acts as an agent of change and a threat to native diversity, either through invasive behavior or genetic contamination.
At the same time, the national Strategy for the Conservation of the Iberian Crayfish approved in 2024 by the Ministry for Ecological Transition describes the animal as a native member of the Austropotamobius pallipes complex. It aims to sharply reduce its high extinction risk, coordinate work across thirteen autonomous communities, and guide recovery plans at regional level.
That strategy rests on genetic studies that interpreted the diversity of crayfish lineages in the peninsula as evidence of a local origin and considered a historical introduction from Italy unlikely. The new archival work tells a different story by tying Iberian populations directly to Tuscany, with dates, names, and even the royal payment recorded on paper.
So what happens when a species that the law treats as native and vulnerable turns out to be a carefully documented import from another country?
A policy puzzle for Spain’s rivers
For decades, Spanish agencies have spent money and effort trying to keep this crayfish from disappearing. The national strategy highlights a long list of pressures that will sound familiar to anyone who lives near a stressed river. Drought and shrinking summer flows.
Dirty water. Illegal harvest. Above all, outbreaks of crayfish plague, a disease linked to the arrival of other exotic crayfish that has wiped out most local populations since the 1970s.
To respond, authorities proposed measures such as protecting and restoring habitat, improving water quality, reinforcing key populations, running captive breeding programs, and limiting the spread of non-native crayfish species. They also called for standardized monitoring, applied research, and public education campaigns.
Many of those actions would still make sense even if the species is officially reclassified. Healthy headwater streams are good for much more than crayfish. Yet the basic justification shifts. Are managers trying to save a unique native lineage or maintain a long established but foreign one while keeping even newer invaders out?
Clavero is blunt about it. In the press release from the Doñana Biological Station he argues that it “makes no sense for administrations to continue treating the Italian crayfish, an introduced species, as one of their conservation priorities” and calls for strategies to be reconsidered in light of the evidence now on the table.
Other specialists quoted in Spanish media warn that labeling a species present since the 16th century as invasive could open a legal and scientific Pandora’s box. They point out that this crayfish has been woven into rural economies and cultural landscapes for generations and that a sudden shift in status could leave the few remaining strong populations without any protection at all.
What does “native” really mean?
Behind this one crustacean sits a broader question that many countries are quietly wrestling with. When we defend a “native” species, are we protecting nature as it looked before large-scale human changes, as it functions today, or as we remember it from childhood fishing trips?
Spanish law already allows some flexibility for species introduced long ago that have social or economic relevance. Including the Italian crayfish in the national catalog of invasive alien species would trigger strict bans on release, farming, and trade, and set eradication or strong control as the official goal.
That scenario would clash head on with existing programs that still aim to maintain or even expand its range in certain basins.
To a large extent, the fate of this crayfish will depend on how policymakers weigh historical origin against current ecological roles and social values. The study by Clavero and Sempere shows that bringing historians into conservation debates can completely redraw the map of what we think is native. It also suggests that many other “cryptic” species could change category once someone opens the right archive box.
For now, the Italian crayfish is a small animal carrying five centuries of human choices on its back. A royal whim in Philip II’s gardens, a peasant delicacy, a symbol of river loss, and maybe an introduced species protected by mistake.
The study was published in Biological Conservation.
