Molecular and morphological evidence for three species of Diplostomum (Digenea: Diplostomidae), parasites of fishes and fish-eating birds in Spain

Abstract

Background: Recent molecular studies have revealed high species diversity of Diplostomum in central and northern Europe. However, our knowledge of the distribution of Diplostomum spp. in the southern distributional range in Europe of the snail intermediate hosts (Lymnaea stagnalis and Radix spp.) is rather limited. This study aims to fill this gap in our knowledge using molecular and morphological evidence.

Diversity, specificity and speciation in larval Diplostomidae (Platyhelminthes: Digenea) in the eyes of freshwater fish, as revealed by DNA barcodes

“…S5). Data are from the present study and Galazzo et al (2002), Niewiadomska and Laskowski (2002), Moszczynska et al (2009), Locke et al (2010a, Rellstab et al (2011), Cavaleiro et al (2012, Behrmann-Godel (2013), Chibwana et al (2013), Georgieva et al (2013), Haarder et al (2013), Blasco-Costa et al (2014), Pérez-del-Olmo et al (2014), Kuhn et al (2015), Otachi et al (2015) and Kania and others (unpublished, GenBank accession numbers KJ888995-013). studies (disagreement in the boundaries of at least nine species).…”

“…Molecular links to adults from avian definitive hosts are usually needed to identify, rather than merely discriminate, species of metacercariae (Galazzo et al, 2002;Locke et al, 2010aLocke et al, , 2011Georgieva et al, 2013;Pérez-delOlmo et al, 2014). However, even when sequences are obtained from adult diplostomids, often not all species detected in surveys of metacercariae are resolved (Galazzo et al, 2002;Georgieva et al, 2013;Pérez-del-Olmo et al, 2014). The result is a sequence database dominated by unidentified, provisional species, many of which have been distinguished primarily through DNA sequence analysis.…”

“…In addition, species were delineated based on gaps in sequence divergence detected using Automatic Barcode Gap Discovery (ABGD, Puillandre et al, 2012). The primary criterion for selecting outcomes was consistency of the two approaches (BINs, ABGD) with the conclusions of prior studies, particularly Galazzo et al (2002), Locke et al (2010a), Chibwana et al (2013), Georgieva et al (2013), Blasco-Costa et al (2014, Pérez-del-Olmo et al (2014), O'Hear et al (2014) and Otachi et al (2015). After establishing consistency, the methods were used to extrapolate for unknown species.…”

“…Aside from their importance in fish health, eye-dwelling diplostomids are frequent subjects of evolutionary and ecological studies (e.g., Ballabeni and Ward, 1993;Kalbe and Kurtz, 2006). However, diplostomid metacercariae are difficult to identify morphologically and molecular methods are often used to distinguish species (Locke et al, 2010a,b;Rellstab et al, 2011;Cavaleiro et al, 2012;Behrmann-Godel, 2013;Chibwana et al, 2013;Désilets et al, 2013;Georgieva et al, 2013;Ndeda et al, 2013;Blasco-Costa et al, 2014;Pérez-del-Olmo et al, 2014;Kuhn et al, 2015;García-Varela et al, 2015;Mateos-Gonzalez et al, 2015;Otachi et al, 2015). Consequently, DNA sequences from diplostomids are accumulating from all over the world, particularly from Diplostomum spp.…”

“…Consequently, DNA sequences from diplostomids are accumulating from all over the world, particularly from Diplostomum spp. Sequences can clarify whether morphological heterogeneity represents interspecific (BlascoCosta et al, 2014;Faltý nková et al, 2014;Pérez-del-Olmo et al, 2014) or intraspecific variation among metacercariae (Cavaleiro et al, 2012;Otachi et al, 2015). Molecular links to adults from avian definitive hosts are usually needed to identify, rather than merely discriminate, species of metacercariae (Galazzo et al, 2002;Locke et al, 2010aLocke et al, , 2011Georgieva et al, 2013;Pérez-delOlmo et al, 2014).…”