DNA barcoding of the medically important freshwater snail Physa acuta reveals multiple invasion events into Africa

Abstract

The medically important freshwater snail Physa acuta is highly invasive and has been reported in several freshwater environments across Africa. To identify species and provide initial insights into the origins of P. acuta into African freshwater environments standard molecular barcoding analyses, using the mitochondrial cytochrome c oxidase subunit I gene (COI), was performed on P. acuta isolates from Angola, Burundi and South Africa. Phylogenetic analyses of isolates from Africa could not be distinguished from P. acuta populations from other countries. Comparisons of COI sequences between isolates of P. acuta showed there to be no geographically specific clusters and the African isolates were distributed across four distinct unrelated clades suggesting several independent invasion events. Haplotype analyses indicated that there were a high number of haplotypes with low variation between them, which led to significant differences in AMOVA analyses between countries. This was further evidence of multiple invasion events suggesting multiple novel haplotypes being continually and independently introduced to each country. This approach not only provides initial insight into the invasion of Africa by P. acuta but a molecular method to monitor and manage the use of an agent of biological control.

DNA Barcoding and Distribution of Gastropods and Malacostracans in the Lower Danube Region

“…Here, for performing pairwise genetic distances, the 3% molecular threshold was used. The calculated intraspecific and interspecific divergence values for gastropods (Table 3) were comparable to those reported for species retrieved from the Portuguese coast, Vaal River and Adriatic Sea, varying in the 8.44-74.67% and 0-2.9% intervals, respectively [66][67][68]; and for amphipods and mysids collected from the Pacific coast of Canada, the Black Sea, the Caspian Sea, Danube River and Don and Rhine river systems, these values were in 0%-4.3% and 4.92-34.2% intervals [69][70][71]. These findings support the efficacy of DNA barcoding based on COI gene sequencing in species delineation.…”

A checklist of larval Digenea (Platyhelminthes: Trematoda) in molluscs from inland waters of Argentina: one hundred years of research

“…Moreover, some of the birds and mammals that act as definitive hosts, such as Otaria flavescens in Chile and Brazil (Pereira et al , 2013; Hermosilla et al , 2018), and Laurus dominicanus in Chile (Gonzalez-Acuna et al , 2009), are known to migrate in the southern part of the American continent. Cosmopolitan host species such as Physella acuta (Lawton et al , 2018; Pantoja et al , 2021) and migratory bird species from other continents are also in the checklist, making the present work of potential global interest. For instance, many migratory shorebirds of the families Charadriidae and Scolopacidae breed in the tundra of the Northern Hemisphere, and then migrate southwards to spend the non-breeding period in coastal and inland wetlands of South and Central America.…”

Molecular epidemiological analyses reveal extensive connectivity between Echinostoma revolutum (sensu stricto) populations across Eurasia and species richness of zoonotic echinostomatids in England

“…Snails were then dissected and checked for prepatent (larval) infections. Only lymnaeid snails from nine English sites were infected with echinostomatids ( Table 1 ) and their identification was further evaluated using cox 1 DNA barcoding and phylogenetic approaches employed by us previously [ 33 , 34 ] ( S1 and S2 Tables). Representative samples of each cercarial isolate (a group of identical individuals collected from a single host at one point in time [ 26 ]) were examined live with neutral red stain under a stereomicroscope for initial identification using a key to larval digeneans [ 35 ] and ~20 of each isolate were fixed in 4% formalin for morphological analysis.…”