What now – an alien snail species in Lake Malawi!

Blog 17 Apr 2024
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Graphical abstract of Jones et al.

Like our previous posting on an invasive alien freshwater snail species in Malawi, our recent observation of Pseudosuccinea columella is now published within Parasites & Vectors. In contrast to Orientogalba viridis, however, our first report on P. columella here adds to a growing list of neighbouring African countries where this invasive species is now found.

Presumably originating from Central America, the Caribbean or the southern part of North America, P. columella has progressively dispersed globally. This peripatetic history is thought to have started over 100 years ago and followed shipping routes involved in the aquaria trade. Today, this snail species has been reported from 22 countries across the world, inclusive of countries in Europe, Oceania and South America.

In consideration of snail-borne disease globally, this snail is somewhat unusual for it evolved independently to those Eurasian species, and their associated parasitic trematodes, and yet is inherently able to transmit liver flukes of medical and veterinary importance. Its expanding presence therefore creates new opportunities for altered transmission of fascioliasis thus we call for a greater ‘Onehealth’ scrutiny of this disease across Malawi.

Our finding of P. columella in Lake Malawi itself has additional significance in this globally important biodiversity hotspot, particularly when environmental stewardship of ‘natural’ versus ‘invasive’ species is considered. It raises some troubling questions, for example, how common is this snail species within the lake and is it a harbinger of wider habitat and ecological change?  Further surveillance of snails along its shoreline is required.