First record of the freshwater jellyfish Craspedacusta sowerbii Lankester, 1880 in Greece suggests distinct European invasion events

Abstract

This contribution presents the first record of the freshwater jellyfish Craspedacusta sowerbii Lankester, 1880 in Greece. The species was found in a water transfer canal adjacent to Lake Marathon, 45 km northeast of Athens; this is the southernmost record of this invasive alien medusa in the Balkan Peninsula and Europe. A review of recently published records shows that this species has expanded its range in Europe and the Mediterranean countries. Genetic analysis of the Greek specimen suggests that the phylogeny of C. sowerbii needs further evaluation since we are probably dealing with a distinct species within the genus Craspedacusta, and that the Greek population represents a distinct invasion event from that previously recorded in central Europe. However, due to a lack of molecular information on the native and invasive ranges, further phylogenetic studies are necessary to clarify this issue.

Hidden diversity under morphology–based identifications of widespread invasive species: the case of the ‘well–known’ hydromedusa Craspedacusta sowerbii Lankester 1880

“…3 and 6).The two first invasions are connected (or simply share similar sequence) with their respective Chinese populations. This was already detected by Karaouzas et al (2015), suggesting that the phylogeny of the genus is in need of further investigations, as genetic distances between the C. sowerbii clades are around 15 %. In the available Cox1 information for olindiid species, all genera except Craspedacusta are represented by a single species or haplotype, making difficult to discuss about the expected range of genetic distances at species level.…”

“…The Cox1 and 16S mitochondrial regions as well as the nuclear ITS region (ITS1-5,8S-ITS2) were sequenced as proposed by Fritz el al. (2009) and Karaouzas et al (2015) for comparative purposes. Rayner and Appleton (1992); striped circle, Rayner (1988) and Rayner and Appleton (1989); solid circle, present record.…”

“…The possible introduction vectors of Craspedacusta sowerbii in the recorded new sites generally remain unidentified. Accordingly, several hypotheses about the possible introduction paths have been mentioned in different reports and works on this species (Dumont, 1994;Angradi, 1998;Karaouzas et al, 2015). They can mainly be resumed in two possible vectors: 1) vectors facilitated by human activities, and 2) natural vectors.…”

“…C. sowerbii colonizes all types of freshwater habitats, i.e. streams, freshwater lakes, ponds, reservoirs and rivers (Raposeiro et al, 2011;Karaouzas et al, 2015). C. sowerbii was first described from specimens found in a water-lily tank in Regent's Park, London, England in 1880 (Lankester, 1880a).…”

“…C. sowerbii was first described from specimens found in a water-lily tank in Regent's Park, London, England in 1880 (Lankester, 1880a). Later, the species was reported from many different localities: United States (Garman, 1916), Hawaii, South Australia (Thomas, 1950), New Zealand, the Philippines, China, Japan (Acker, 1976), France, Sweden, Portugal (Ferreira, 1985), Canada (McAlpine et al, 2002), Spain (Pérez-Bote et al, 2006;Medina-Gavilán and González-Duarte, 2018), Mexico (Moreno-Leon and Ortega-Rubio, 2009), Brazil (Silva and Roche, 2007), Uruguay (Mañé-Garzón and Carbonell, 1971), India (Riyas and Kumar, 2017), Italy (Schifani et al, 2018), Chile (Fraire-Pacheco et al, 2017;Fuentes et al, 2019), Turkey (Balik et al, 2001;Bekleyen et al, 2011), Israel (Gasith et al, 2011) and Greece (Karaouzas et al, 2015). From the African continent, it has been recorded with certainty only from South Africa (Rayner, 1988;Rayner andAppleton, 1989, 1992).…”