First Detection of the Crayfish Plague Pathogen Aphanomyces astaci in Costa Rica: European Mistakes Should Not Be Repeated

Abstract

The crayfish plague pathogen Aphanomyces astaci is one of the main factors responsible for the decline in European and Asian native crayfish species. This pathogen was transported to these regions through its natural carriers, North American crayfish species, which were introduced during the last century. Since then, the carrier species and the pathogen have spread worldwide due to globalization and the highly invasive nature of these species. In Europe, five carrier species have been categorized as high-risk as they are responsible for the loss of provisioning services, which endangers freshwater ecosystems. The red swamp crayfish Procambarus clarkii, in particular, is currently one of the most concerning species as its spread threatens crayfish biodiversity and freshwater ecosystems worldwide. In this study, we describe the first detection of A. astaci in an introduced population of P. clarkii in Central America, specifically in Costa Rica. Using molecular approaches, we analyzed 48 crayfish samples collected from Reservoir Cachí and detected the presence of A. astaci in four of these samples. The introduction of P. clarkii and the incorrect management of the species (related to its fishery and the commercialization of live specimens) over the past decades in Europe are mistakes that should not be repeated elsewhere. The detection of the pathogen is a warning sign about the dangerous impact that the introduction of this invasive crayfish may have, not only as a carrier of an emerging disease but also as a direct risk to the invaded ecosystems. Our results may serve to (1) assess current and future consequences, and (2) direct future research activities, such as determining the potential impacts of A. astaci on native decapod species, or on other introduced crayfish species that are used for aquaculture purposes, such as Cherax quadricarinatus.

Pathogenicity of animal and plant parasitic Aphanomyces spp and their economic impact on aquaculture and agriculture

“…A. astaci is an obligate parasite specialized on freshwater crayfish (Söderhäll and Cerenius, 1999;Diéguez-Uribeondo, 2006). This oomycete is known to have a North American origin, and could occasionally also be harboured by other decapods such as freshwater crabs or shrimps (Putra et al, 2016;Svoboda et al, 2017;Martín-Torrijos et al, 2021a). Aphanomyces frigidophilus is known to infect the eggs of several salmonid species (Ballesteros et al, 2006).…”

Microplastics in feed cause sublethal changes in the intestinal microbiota and a non-specific immune response indicator of the freshwater crayfish Procambarus clarkii (Decapoda: Cambaridae)

“…This crayfish has been recognized as the species with the greatest ecological plasticity of all decapods ( Rodríguez et al, 2015 ). It was introduced in Costa Rica around 1966 and is now widespread in the country ( Martín-Torrijos et al, 2021 ). This decapod species is economically and ecologically important, but little is known about its gut microbiota.…”

Variations in the Sporulation Efficiency of Pathogenic Freshwater Oomycetes in Relation to the Physico-Chemical Properties of Natural Waters

“…Animal pathogenic oomycetes are a cause of serious diseases worldwide [ 1 , 2 , 3 ], and in freshwater ecosystems species from the genera Aphanomyces and Saprolegnia are the most significant, since they cause severe disease outbreaks both in aquaculture and in the wild [ 4 , 5 , 6 , 7 ]. Crayfish plague, a disease caused by Aphanomyces astaci is responsible for decimating the populations of indigenous crayfish species in Europe [ 8 ] and elsewhere (e.g., Asia and South America) [ 9 , 10 , 11 , 12 ]. The pathogen was introduced into Europe along with North American non-indigenous invasive crayfish species which now act as its carriers, being mostly resistant to infection due to a long co-evolution with the pathogen [ 13 , 14 ].…”