Historical museum collections help detect parasite species jumps after tilapia introductions in the Congo Basin

Abstract

This study highlights the value of museum collections in invasion biology. It focuses on introduced tilapias, Oreochromis niloticus and Coptodon rendalli in the Congo Basin and their monogenean (Platyhelminthes) gill parasite fauna. Oreochromis niloticus was introduced throughout the Congo Basin while C. rendalli was introduced into the Lower Congo, but is native to the Middle and Upper Congo. In order to study the impact of these stocking events on the native parasite community we investigate the co-introduction and host switching of their parasites. Post-introduction material is compared with pre-introduction samples from museum collections of 5 native tilapias in the Congo basin. Nine of the known parasites of O. niloticus were co-introduced, while one, Cichlidogyrus rognoni, is missing and possibly not established. In contrast, no parasite species were found co-introduced with C. rendalli into the Lower Congo. The parasite fauna of Tilapia sparrmanii shared no species with O. niloticus. Oreochromis mweruensis shared five species with O. niloticus, but these were also found on the pre-introduction samples, and are considered native to both hosts. We report three putative host switches: Cichlidogyrus sclerosus and Cichlidogyrus tilapiae to Coptodon tholloni in the Lower Congo Basin and Gyrodactylus nyanzae to Coptodon rendalli in the Upper Congo.

Somewhere I belong: phylogeny and morphological evolution in a species-rich lineage of ectoparasitic flatworms infecting cichlid fishes

“…Fish specimens belonging to Cichlidae Bonaparte, 1835 (Cichliformes), the nothibranchiid genus Aphyosemion Myers, 1924 (Cyprinodontiformes: Nothibranchiidae), and Polycentropsis abbreviata Boulenger, 1901 (Ovalentaria, incertae sedis: Polycentridae) were collected during various expeditions across Africa between 2008 and 2019 and from few specimens from aquaculture facilities in France (Appendix 1). As samples collected during these expeditions have been included in previous studies, sampling details can be found in the respective publications (Vanhove et al 2011(Vanhove et al , 2013Muterezi Bukinga et al 2012 ; Pariselle et al 2015aPariselle et al , 2015bJorissen et al 2018aJorissen et al , 2018bJorissen et al , 2020. We dissected the (which was not certified by peer review) is the author/funder.…”

“…These introductions might also increase the chances of co-introduction for their parasites and create more opportunities for host range expansions (e.g. Jorissen et al 2020). To avoid these biases, (which was not certified by peer review) is the author/funder.…”

“…Host-parasite interactions are usually well-preserved in natural history collections (Harmon et al . 2019; Jorissen et al . 2020) because often parasites remain attached to the body or inside the body of the collected specimens.…”

No vagina, one vagina, or multiple vaginae? An integrative study ofPseudaxine trachuri(Monogenea, Gastrocotylidae) leads to a better understanding of the systematics ofPseudaxineand related genera

“…Considering that in a single species, P. trachuri, we found specimens with and without what look like "multiple lateral vaginae", we believe that the taxa mentioned above, and probably others, should be re-examined, preferably using both morphology and molecular information. More generally, we stress the importance of integrative taxonomy [21] for the taxonomy of parasites, including correct identification of hosts using both morphology and molecular analysis as in the present work and recent studies [5,[8][9][10]43] and, whenever possible, deposition of hosts in curated collections [12,36,39,42].…”

Whole genome resequencing data enables a targeted SNP panel for conservation and aquaculture ofOreochromiscichlid fishes

“…Nile tilapia (O. niloticus), in particular, is becoming established across Africa outside of its natural range, including in South Africa (D'Amato et al, 2007), Zambia (Deines et al, 2014), Zimbabwe (Marufu & Chifamba, 2013), the Democratic Republic of Congo (Goudswaard et al, 2002;Mamonekene & Stiassny, 2012), Kenya (Angienda et al, 2011), as well as Tanzania , with reports of either replacement of the native species or extensive introgressive hybridization (Bradbeer et al, 2019;Shechonge et al, 2018). There is also evidence of parasite transmission from introduced tilapia species to native species (Jorissen et al, 2020). Despite this, intentional movement and stocking of tilapia species into natural water bodies continues in many regions of Africa (Genner et al, 2013).…”