Parasite communities and genetic structure of non-native pumpkinseed,Lepomis gibbosus, in different Black Sea drainages of Ukraine

Abstract

In recent years, pumpkinseed Lepomis gibbosus (Actinopterygii: Centrarchidae) have spread intensively to many parts of Europe, including Ukraine. In this study, we (1) assess intra-population genetic variability in five widely-spaced Ukrainian pumpkinseed populations and compare their population genetic structure with other European populations and (2) provide a comprehensive survey of pumpkinseed parasites across the region. Discriminant analysis of principal components and FST analyses based on microsatellites indicated that all five populations formed discrete clusters. Within Europe, Ukrainian populations were most closely associated with populations from the River Danube, suggesting that the Danube is the main source of all Ukrainian pumpkinseed populations. The parasite fauna comprised 15 taxa, most of which (92%) were native to North America (monogenea Onchocleidus similis and O. dispar; myxozoan Myxobolus dechtiari). Parasites acquired in the species' new range occurred accidentally, with only Trichodina ciliates found relatively frequently and the eye flukes Diplostomum pseudospathaceum and Tylodelphys clavata occurring at higher prevalence. Absence of specific monogeneans in pumpkinseed from estuaries (Khadzhibey and Sukhyi Lymans) indicates low tolerance of Onchocleidus species to salinity.

Comparative Analysis of Parasite Load on Recently Established Invasive Pumpkinseed Lepomis gibbosus (Actinopterygii: Centrarchidae) in Europe

“…3 lineage collected from pumpkinseed. Though a recent study of pumpkinseed populations in southern Ukraine failed to confirm the presence of this parasite species in the region [ 48 ], further expansion of P. centrarchi to the east is to be expected. The definitive hosts of this parasite are herons (Ardeidae) [ 38 , 67 ], which spread the eggs of the parasites to new localities.…”

“…Among the other co-introduced parasites, the myxozoan M. dechtiari has already been recorded in Ukraine in Lake Kartal and the brackish Khadzhibey Estuary [ 48 ]. This parasite is currently known in invasive pumpkinseed in Hungary, Moldova and Portugal [ 32 , 44 ].…”

“…Two co-introduced monogenean species , O. dispar and O. similis , are widely distributed in Europe, having been recorded in non-native pumpkinseed populations in Austria, Bulgaria, Croatia, Czechia, France, Germany, Italy, Norway, Serbia and Slovakia [ 6 , 33 , 42 , 43 , 47 , 68 , 69 ]. In Ukraine, both species are known from the Danube basin [ 70 ], but only O. dispar has been found in the Dnipro (Dnieper) river basin [ 34 , 48 ]. In Czechia, while both Onchocleidus species have previously been recorded from pumpkinseed caught in the Dyje River in the Danube River basin and the Donbas sandpit in the Morava River basin [ 6 , 42 ], recent pumpkinseed populations in waterbodies of the Dyje River floodplain appear to be parasitised with O. dispar only [this study, 42 ].…”

“…The occurrence of pumpkinseed in the Bug River basin (Dobrotvir Reservoir) is new, and our finding is, in fact, the first record of this fish species in the Vistula River basin, the species only having been recorded in the Oder River basin in the Baltic Sea catchment prior to this study [ 73 , 74 ]. Despite being a recent population, pumpkinseed parasite species richness in the Dobrotvir Reservoir was relatively high, reaching the same level as that found in other Ukrainian localities [ 48 ]. However, most parasite species found only occurred accidentally, with the North American trematodes P. centrarchi predominating, resulting in the high dominance index recorded at this locality.…”

“…However, despite the recent rapid expansion of pumpkinseed in both Czechia and Ukraine, data on their parasites are only known from a relatively small area of their host distribution. In Ukraine, pumpkinseed parasites have been studied in the Dnieper basin, Lower Danube and brackish water estuaries [ 29 , 34 , 48 ], while data from the western part of the country remains absent. Data from Czechia includes studies limited to a single parasite taxon, i.e.…”