Parasite acquisition by the invasive Chinese sleeper (Perccottus glenii Dybowski, 1877) (Gobiiformes: Odontobutidae) in Latvia and Ukraine

The Perccottus glenii is one of the most invasive of European fish species. During August-September 2019, we examined Chinese sleeper from six waterbodies in Latvia and Ukraine for parasites. Seventeen parasite species were registered, including two ciliate species, one coccidia, one monogenean, one cestode, six trematodes, three nematodes, one acanthocephalan, one parasitic copepod, and one bivalve glochidia. Maximum species richness was registered in Ukraine, with eight species at Vylkove and three species at Lake Kartal. Numbers in Latvia were generally lower with three species at Ilgas and just one at Gailezers. The parasite fauna registered in Latvia was poor overall, the richest site being the University pond. Two non-native parasite species were registered, the monogenean Gyrodactylus perccotti and the copepod Neoergasilus japonicus. Gyrodactylus perccotti was observed in Lake Kartal and the Danube delta in Ukraine, but not in Latvia, while N. japonicus only occurred in the University Pond in Latvia. This is the first record of this species in Latvia. Low parasite acquisition by the Chinese sleeper in Latvia may be caused by the release of this fish from aquaria, which is commonly registered in the region. It is likely that such low parasite loads have contributed to the formation of stable populations and the subsequent increase in expansion.     

Amur sleeper (Perccottus glenii Dubowski, 1877) spreading in the Danube River Basin

Whereas earlier Amur sleeper (Perccottus glenii) findings in the Danube River were only single specimens, data reported in this study represent the first record on establishment of a local population. An overview of the spread of the Amur sleeper in the Danube River basin is also presented.     

The Chinese sleeper (Perccottus glenii Dybowski, 1877) in Ukraine: New data on distribution

The Chinese sleeper Perccottus glenii Dybowski, 1877 is one of the most successful alien species in Europe today. This article is a review of the current distribution of the species in Ukraine using published data, own field studies (2005–2016) and collections from museums and colleagues. The Chinese sleeper has been confirmed in the Vistula, Danube, Dniester, Southern Bug and Dnipro river basins, with earlier occurrence (1970s–90s) in the Vistula, Danube and Dniester river basins. As a result, the species is distributed more evenly in these river basins. The Chinese sleeper was first recorded in the Dnipro and Southern Bug river basins in the 21st century; hence, its occurrence is still irregular. Present data suggest that, in some regions, the species could inhabit not only floodplains and bays but also fluvial river sections.     

Non-selective predator – the versatile diet of Amur sleeper (Perccottus glenii Dybowski, 1877) in the Vistula River (Poland), a newly invaded ecosystem

The Amur sleeper diet spectrum was investigated in addition to its spatial, seasonal and size-related changes, in order to predict which groups of native prey would be most affected by this exotic predator that has rapidly invaded many Eastern and Central European inland waters in recent decades. In total, 527 Perccottus glenii individuals were collected in four sites in the Włocławski Reservoir (the Vistula River, Baltic basin, Poland). Altogether 50 food categories were identified, including crustaceans, insects, molluscs, annelids, araneids, fishes and amphibians. Most of them were associated with aquatic vegetation, indicating that the Amur sleeper collects its prey from the submerged plants rather than directly from the bottom sediments. Amphipods and chironomid larvae, supplemented by zygopteran larvae and molluscs, composed the main forage base in all studied sites, although their importance was varied. The diet composition differed among P. glenii size-groups. Significant variation was found in numeric abundance of amphipods, chironomid larvae, fish and zygopteran larvae (Kruskal–Wallis P < 0.01). Seasonal changes in the diet were also observed whereby in spring and summer, dipteran larvae and amphipods were prevalent food items; the importance of molluscs and zygopteran larvae increased considerably in September; and fish showed the highest occurrence in June, July and August. The broad diet spectrum of the Amur sleeper indicates that it is a non-selective, opportunistic predator and that several taxonomic groups of native hydrofauna as well as macroinvetebrates and fish may be affected by its presence. The highly flexible feeding strategy undoubtedly favours Amur sleeper expansion in invaded watersheds.     

A checklist of parasites in non‐native populations of rotan Perccottus glenii Dybowski, 1877 (Odontobutidae)

This review presents data on diversity, prevalence, and distribution of protistan and metazoan parasites in non‐native populations of the rotan Perccottus glenii. The information was collected using peer reviewed journals, difficult to access grey literature, and original data of the authors. As a whole, 70 literature sources from 1971 to 2012 were analyzed. The data originate from five of the 17 countries already colonized by P. glenii. A total of 97 parasite species/taxa are listed, each with the location in/on the host, geographical localities, countries, and literature sources. Where available, the number of fish examined as well as the prevalence and range of infection intensity are cited from the respective sources. Attention is given to host‐specific parasites because the rotan is a vector of their new geographical distribution. The current state and perspectives for further research are discussed.     

Otolith Morphology of Amur Sleeper Perccottus glenii (Odontobutidae)

Journal of Ichthyology - Morphology of the sagitta, lapillus, and asteriscus is described in Amur sleeper Perccottus glenii, 19–245 mm TL. The sagitta is characterized by an almost quadratic...     

Parasites of the introduced Amur sleeper, Perccottus glenii (Osteichthyes): Alpha-diversity of parasites and age of the host

Three age groups of the Amur sleeper have been studied: underyearlings (0+), two-year-olds (1+), and three- and four-year-olds (2+ and 3+). The long-cycle parasites prevalent in all three age groups are the merocercoids of Ophiotaenia europaea, third-stage juveniles of Spiroxys contortus, and metacercariae of Isthmiophora sp. and Prohemistomidae gen. sp. Different age groups of the Amur sleeper have different roles in the life cycle of O. Europaea. Underyearlings are second intermediate hosts of O. europaea, and Amur sleepers aged 1+ and older are parathenic hosts. The alpha-diversity of long-cycle parasites of the Amur sleeper increases with the age of the host.     

Interactions of the introduced rotan Perccottus glenii Dybowski, 1877 (Osteichthyes, Odontobutidae) with aboriginal fish species: The parasitological aspect

This study was conducted in the water-filled Neverovo sandpit, located in Ruza district of Moscow province. This water body is inhabited by 6 fish species, including the introduced rotan. Twelve species of parasites were recorded in/on the rotan, and most of them circulate using aboriginal fish species. Reliable evidence of the involvement of the rotan in the circulation of a parasite species native to the water body-recipient (Ergasilus sieboldi) was obtained for the first time. Rotan does not play a significant role in the circulation of 11 other parasite species, or, at least, quantity estimations of its role were not yet undertaken.     

Variation of Otolith Structure in Amur Sleeper Perccottus glenii (Odontobutidae) Populations from Central Russia

Journal of Ichthyology - Development of annual increments on the otoliths (sagittae) of Amur sleeper Perccottus glenii, as well as the sagitta shape and bilateral asymmetry, is analyzed in the...     

Larval development of the Amur sleeper Perccottus glenii (Perciformes, Gobioidei, Odontobutidae) and the origin of fish of the suborder Gobioidei

The external morphology and development of skeletal elements is investigated in larvae and fry of one of the most generalized representatives of the suborder Gobioidei—the Amur sleeper Perccottus glenii. It is characterized by an indirect type of development accompanied by the expressed metamorphosis, according to Balon’s classification (1985). Fry of P. glenii are capable of an active mode of life and exogenous feeding almost immediately after hatching which favors a wide distribution of this species. Morphogenesis of previously revealed diagnostic characters of Gobioidei is investigated. New apomorphies are found also indicating to a high separation level of P. glenii from representatives of other suborders of Perciformes. At the same time, it is found that some developmental traits of P. glenii are characteristic of generalized Perciforems. Some advanced characters acquired in parallel with representatives from the group of suborders Blennioidei s. l. also indirectly indicate that P. glenii and, generally, Gobioidei belong to Perciformes. Analysis of special traits of development of the skeleton of P. glenii supports the ideas of Regan (1911) on the origin of Gobioidei from generalized Percoidei. With consideration of advanced characters, general for Gobioidei and the suborders Trachinoidei, Notothenioidei, Zoarcoidei, and Blennioidei of the group Blennioidei s. l., it is assumed that Gobioidei and Blennioidei s. l. stem from the same group or from the related groups of Percoidei.     

Distribution of the fish rotan (Perccottus glenii Dybowski, 1877) in the Irtysh River basin and analysis of possible consequences for environment and people

Since 1916, rotan (Perccottus glenii Dybowski, 1877) has widely distributed in northwestern Eurasia. In 1973–1976, rotan populations were first detected in the basin of the Irtysh River: in Lake Peschanoe (Mertvoe) of Chelyabinsk oblast in the basin of the Tobol, a tributary of the Irtysh. In 1975, this fish was introduced to one of the ponds of the city of Chelyabinsk. Analysis of the spatiotemporal dynamics of findings shows that earlier records of the fish correlate with the network of roads, and later findings, with the river network. The results of a special inspection of isolated and floodplain water bodies (n = 77) performed within Chelyabinsk, Kurgan, Omsk, and Tyumen oblasts in 2006 indicate that at present this unwanted invader occurs in the major part of the Tobol basin. The northernmost finding of this species is from the floodplain of the Tobol in the vicinity of Tobolsk, from the Karachino oxbow (58°02′N, 68°10′E). Rotan has also been found at the Irtysh headwaters as well as in the basins of its other tributaries: Ishim and Om. The expansion of rotan threatens the floodplain water bodies of the middle Irtysh. This species carries diseases, competes with other fish species for food, and actively eats young fish of these species. Therefore, the data on rotan distribution in the tributaries of the Irtysh should be taken into account when analyzing the dynamics of the fish community of this river. Biology of rotan assumes its influence on the functioning of the natural foci of opisthorchiasis.     

Occurrence,dispersion and habitat preferences of Amur sleeper (Perccottus glenii) in oxbow lakes of a large river and its tributary

Aquatic Ecology - Amur sleeper (Perccottus glenii) is currently one of the most invasive fish species in Europe. This inspired our research to identify potential channels of emigration in two...     

The influence of temperature on the activities of digestive carbohydrases in Amur sleeper (Perccottus glenii Dyb.) during the winter

The total amylolitic activity and sucrase activity in the Amur sleeper intestine are similar to those in typical and facultative benthophages. The optimal temperature of starch hydrolysis is 50 °C. The sleeper’s carbohydrases are more tolerant to the increase in water temperature during winter than similar enzymes in cyprinids.     

First Data on Seasonal Changes in Feeding of the Amur Sleeper Perccottus glenii (Odontobutidae) in the South of West Siberia

Journal of Ichthyology - The data on feeding of the Amur sleeper Perccottus glenii in a pond located in the southern taiga subzone in West Siberia obtained in May–October 2017 are presented....     

Variation trends in the parasite assemblages of the Chinese sleeper Perccottus glenii (Actinopterygii: Odontobutidae) in its native habitat

The diversity of parasite assemblages in the Chinese sleeper Perccottus glenii, at the level of specimen and population of the host, is manifested through three components: the number of species, the evenness of their abundance, and the taxonomic diversity. Variations in the diversity depend on the local characteristics of water bodies, as well as the sexual and dimensional factors of the host. This study was performed in four water bodies of the Russian Far East (Primorskii krai and Sakhalin Island).