Coexistence of Two Invasive Species, Procambarus clarkii and Aphanomyces astaci, in Brackish Waters of a Mediterranean Coastal Lagoon

Laura Martín-Torrijos,Javier Diéguez-Uribeondo,Antonio Pradillo,Angel Jose Correa-Villalona

doi:10.3389/fevo.2020.622434

Laura Martín-Torrijos, Javier Diéguez-Uribeondo + Show 2 more

Open Access

https://doi.org/10.3389/fevo.2020.622434

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Abstract

Procambarus clarkii is a worldwide freshwater invasive crustacean from North America and was first introduced into Europe the 1970s. Along with P. clarkii, another invasive alien species was also spreading: Aphanomyces astaci. This pathogen is listed among the 100 World’s worst invasive species and involved in the European native crayfish decline. Although both species live in freshwater ecosystems, P. clarkii can withstand brackish waters and inhabit estuarine habitats. However, the presence of A. astaci associated to North American crayfishes has never been described in brackish waters. In this study, we have investigated the presence of A. astaci in a P. clarkii population of a Mediterranean coastal lagoon in the Albufera Natural Park, Valencia, Spain introduced in 1976. Our study confirmed the presence of this pathogen, and suggests that A. astaci has been spreading for more than four decades in the mentioned estuarine environment. Mitochondrial ribosomal rnnS and rnnL indicated that the isolated pathogen belongs to d1-haplotype (i.e., D-haplogroup) typically hosted by P. clarkii. The presence of this pathogen in a brackish environment may suggest a better adaptation than other A. astaci strains to adverse conditions, such as high salinity levels. This is a matter of concern for the conservation of European native freshwater crayfish and highlights once more the risk of introducing invasive alien crustaceans.

Highlights

Biological invasions represent one of the main threats to biodiversity
The tolerance of A. astaci to grow in saline environments in its natural carriers, i.e., North American crayfish, have never been investigated
In this study, we report and describe for the first time the presence of the crayfish plague pathogen in a P. clarkii population that lives in a saline environment, a Mediterranean coastal lagoon of the Albufera Natural Park

Summary

Introduction

Biological invasions represent one of the main threats to biodiversity. Some of the alien species causing these invasions are common throughout the world and are driving the existing biodiversity toward homogenization (Piscart et al, 2011). Among the diverse ecosystems affected by invasive alien species, freshwater ecosystems are rapidly altered and according to the European Union the impact of invaders accounts for billions of euros yearly (Tollington et al, 2015). In European freshwater ecosystems, these represent about 53% of all macroinvertebrate invasive species, and almost half of the freshwater decapods in European waters, ca 46%, are invasive species (Karatayev et al, 2009). Five species of freshwater decapods of North American origin, i.e., the freshwater crayfish Faxonius limosus, F. virilis, Pacifastacus leniusculus, Procambarus clarkii, and P. virginalis, are included in a list of invasive alien species of the European Union concern pursuant to Regulation (EUR-lex, 2016) because of the alarming increasing impact to the flora and fauna of European ecosystems (Simberloff and Rejmánek, 2011)

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