Ecological plasticity and commercial impact of invasive marbled crayfish populations in Madagascar

Ranja Andriantsoa,Sina Tönges,Kathrin Theissinger,Frank Lyko,Vitor Coutinho Carneiro,Jörn Panteleit,Jeanne Rasamy

doi:10.1186/s12898-019-0224-1

Abstract

BackgroundThe marbled crayfish (Procambarus virginalis) is a monoclonal, parthenogenetically reproducing freshwater crayfish species that has formed multiple stable populations worldwide. Madagascar hosts a particularly large and rapidly expanding colony of marbled crayfish in a unique environment characterized by a very high degree of ecological diversity.ResultsHere we provide a detailed characterization of five marbled crayfish populations in Madagascar and their habitats. Our data show that the animals can tolerate a wide range of ecological parameters, consistent with their invasive potential. While we detected marbled crayfish in sympatry with endemic crayfish species, we found no evidence for the transmission of the crayfish plague pathogen, a potentially devastating oomycete. Furthermore, our results also suggest that marbled crayfish are active predators of the freshwater snails that function as intermediate hosts for human schistosomiasis. Finally, we document fishing, farming and market sales of marbled crayfish in Madagascar.ConclusionsOur results provide a paradigm for the complex network of factors that promotes the invasive spread of marbled crayfish. The commercial value of the animals is likely to result in further anthropogenic distribution.

Highlights

The marbled crayfish (Procambarus virginalis) is a monoclonal, parthenogenetically reproducing freshwater crayfish species that has formed multiple stable populations worldwide
Our study aims to provide a detailed description of the large population of marbled crayfish in Madagascar
Marbled crayfish populations in those two locations have been known for at least 2 years, with no indications for crayfish plague outbreaks. These results suggest that marbled crayfish do not trigger crayfish plague outbreaks in Madagascar

Summary

Introduction

The marbled crayfish (Procambarus virginalis) is a monoclonal, parthenogenetically reproducing freshwater crayfish species that has formed multiple stable populations worldwide. The genetically homogeneous marbled crayfish has been described as a successful invasive species in various countries [11,12,13,14,15,16,17,18]. This is exemplified by the situation in Madagascar, where marbled crayfish were first introduced around 2005 [11]. In 2017, marbled crayfish had colonized an area of approximately 100,000 km, stretching from the highland to the coast [8].

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