Xenopus laevisas UberXL for nematodes

Abstract

This is the final version of the article that is published ahead of the print and online issue Biological invasion, or the translocation of animals, plants and pathogens to novel habitats, often with human help, is one of the distinguishing characteristics of the Anthropocene (Ellis et al. 2012;Capinha et al. 2015). In numerous cases, declines in biodiversity are directly linked to the spread of highly competitive, generalist invasive species (Ricciardi 2007;Bellard et al. 2016) and many invasive species impact their new ecosystems negatively (Simberloff 2011).In particular, the role of invasive species in the alteration of parasite dynamics in their novel habitats is frequently overlooked (Blackburn and Ewen 2017). Conversely, introduced hosts could cause the amplification of native parasite dynamics, by acting as reservoirs for native parasites that can eventually spill back to native hosts, or conversely, they can dilute these interactions by acting as dead-end hosts for native parasites (Telfer and Bown 2012). These ripples can be felt several links down the food chain, especially in the case of parasites transmitted via trophic interactions (Amundsen et al. 2013).The globally invasive African clawed frog, Xenopus laevis (Daudin, 1802) (Anura: Pipidae) is one of the world's most widely distributed amphibian invaders. Its human-mediated range expansion was initiated in the 1930s through its use as a biological pregnancy assay and a model research animal and later with the help of the pet trade (Gurdon and Hopwood 2000;Weldon et al. 2007;van Sittert and Measey 2016). Currently, its invasive range spans four continents, with established populations mainly in areas with a Mediterranean climate (Lobos and Measey 2002;Measey et al. 2012). However, climate and niche modelling have made it clear that X. laevis still has many potential environments to fill across the globe (Measey et al. 2012;Ihlow et al. 2016;van Sittert and Measey 2016;Rödder et al. 2017).In addition to its status as global invader, X. laevis exhibits recurring range expansion within its native range (Measey and Davies 2011;Measey et al. 2017). These domestic invasions were brought about by its frequent translocation for research and training purposes in the past (van Sittert and Measey 2016) and continues to the here and now through natural dispersal via overland movement and artificial waterbodies (

Genetic characterisation of Tanqua (von Linstow, 1879) (Nematoda: Gnathostomatidae) larval forms including new host and locality records

“…2 B at 40X magnification shows the tooth like projections of the pseudolabia ( tl ) and the large lateral pseudolabia ( lp ). Schoeman et al (2020) describes the pseudolabia as minute and although tooth like projections are not described in text these can be observed in Fig. 6 B of the publication.…”

“…data 18_S. haplotypes) however Schoeman et al (2020) provided morphological description for larval stage (L3) Tanqua sp. from Xenopus laevis , South Africa.…”

“…2 C and D) in the present study show the trunk is heavily annulated and these annulations cover the entire parasite. Schoeman et al (2020) did not describe annulations in the morphological description of L3 Tanqua sp.

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“…Genomic DNA from 12 larval nematodes were extracted according to the method described in Shamsi et al (2019) using DNeasy Blood & Tissue Kits (QIAGEN, Germany) and eluted by 40 μl of elution buffer. Since the 18S gene has been successfully used as a genetic marker for studying Tanqua and other Spirurina parasites in freshwater aquatic species ( Laetsch et al, 2012 ; Choudhury and Nadler, 2018 ; Schoeman et al, 2020 ), samples from 12 larval nematodes were amplified using the primer sets Forward: 35 fm (5′-TATAATGGTGAAACCGCGAACGGC-3′) and Reverse: 18gMm (5′- GGAAACCTTGTTACGACTTTTGCC-3′). The cycling conditions for PCR were as follows, 95 °C for 2 min followed by 95 °C for 30 s, 48 °C for 45 s, 72 °C for 1 min for 40 cycles and a final extension of 72 °C for 10 min.…”

“…haplotypes Tanqua sp . MN526252 Xenopus laevis Limpopo Province, South Africa Schoeman et al (2020) Tanqua sp. OL830839 Channa punctata Bangladesh This study, isolate 674-1 Tanqua sp.…”