A molecular approach to detect hybridisation between crucian carp (Carassius carassius) and non‐indigenous carp species (Carassiusspp. andCyprinus carpio)

Abstract

Environment Agency Kingsmeadow House, Reading, Berkshire, U.K. SUMMARY1. Releases of non-native fish into the wild is an increasing problem posing considerable ecological and genetic threats through direct competition and hybridisation. 2. We employed six microsatellite markers to identify first generation hybrids and backcrosses between native crucian carp (Carassius carassius) and introduced goldfish (C. auratus) and common carp (Cyprinus carpio) in the U.K. We also investigated the genetic characteristics of the taxonomically controversial gibel carp (Carassius spp.) from sites across Europe. 3. Natural hybridisation between goldfish and crucian carp occurs frequently, although hybrids between all other species pairs were observed. Only 62% of British crucian carp populations (n ¼ 21) consisted exclusively of pure crucian carp. In some populations hybrids were so frequent, that no pure crucian carp were caught, indicating a high competitive ability of hybrids. 4. Most hybrids belonged to the F1 generation but backcrossing was evident at a low frequency in goldfish · crucian carp hybrids and goldfish · common carp hybrids. Furthermore, some local populations had high frequencies of backcrosses, raising the opportunity for introgression. 5. Gibel carp from Germany and Italy belonged to two triploid clonal lineages that were genetically closely related to goldfish, whereas all individuals identified from British populations proved to be crucian carp · goldfish hybrids. 6. Our study suggests that the release of closely related exotic cyprinids not only poses a threat to the genetic integrity and associated local adaptations of native species, but may also contribute to shifts in community structure through competitive interactions.

Evolutionary history of two divergent Dmrt1 genes reveals two rounds of polyploidy origins in gibel carp

“…It has been observed widely in many countries of the Eurasian continent (Gui and Zhou, 2010), such as in Britain (Hanfling et al, 2005), Italy (Hanfling et al, 2005), Hungary (Toth et al, 2005), Germany (Hanfling et al, 2005), Croatia (Jakovlic and Gui, 2011), Greece (Liasko et al, 2010), Kazakhstan (Sakai et al, 2009), Russia (Abramenko et al, 2004;Jiang et al, 2013), China (Gao et al, 2012;Jiang et al, 2013;Li and Gui, 2008), and Japan (Takada et al, 2010). Similar to other unisexual polyploid vertebrates, the polyploid gibel carp can reproduce by spermdependent gynogenesis, and many diverse gynogenetic clones have been discriminated by biological traits and molecular markers (Bai et al, 2011;Gui and Zhou, 2010;Guo and Gui, 2008;Yang and Gui, 2004;Zhou et al, 2000a).…”

High male incidence and evolutionary implications of triploid form in northeast Asia Carassius auratus complex

“…Previously, it was recorded only in Japan (Kobayasi, 1971), Russia (Cherfas, 1981), and China (Jiang et al, 1983;Zhou and Gui, 2002). Recently, along with cytogenetic and molecular marker development, it has been extensively observed in many countries of the Eurasian continent, such as in Britain, Italy, Germany (Hänfling et al, 2005), Hungary (Tóth et al, 2005), Greece (Liousia et al, 2008), Czech Republic (Kalous et al, 2007;Veteŝník et al, 2007), Kazakhstan (Sakai et al, 2009), and Croatia (Jakovlić and Gui, 2011). In the past decade, a lot of genetic knowledge including molecular basis of reproduction trait and numerous polymorphic DNA markers has been investigated and characterized from the triploid form (Gui and Zhou, 2010;Gui and Zhu, 2012).…”

Expression characterization of testicular DMRT1 in both Sertoli cells and spermatogenic cells of polyploid gibel carp

“…Gibel carp (Carassius auratus gibelio) has a wide geographic distribution in the Eurasian continent (Gao et al, 2012;Gui and Zhou, 2010;Hanfling et al, 2005;Jakovlic and Gui, 2011;Jiang et al, 1983Jiang et al, , 2013Takada et al, 2010). Its polyploidy origin had been clarified and nominated as a subspecies C. auratus gibelio of Carassius auratus .…”