European River Lamprey Lampetra Fluviatilis in the Upper Volga: Distribution and Biology

After the construction of the Volga Hydroelectric Station and other dams, migration routes of the Caspian lamprey were obstructed. The ecological niches vacated by this species attracted another lamprey of the genus Lampetra to the Upper Volga, which probably came from the Baltic Sea via the system of shipways developed in the 18 th and 19 th centuries. Based on collected samples and observations from sites in the Upper Volga basin, we provide diagnostic characters of adults, and information on spawning behavior. Silver coloration of Lampetra fluviatilis was noted for the first time and a new size-related subsample of “large” specimens was delimited, in addition to the previously described “dwarf”, “small” and “common” adult resident sizes categories. The three water systems: the Vyshnii Volochek, the Tikhvin and the Mariinskaya, are possible invasion pathways, based on the migration capabilities of the lampreys. Dispersal and colonization of the Caspian basin was likely a combination of upstream and downstreams migrations. First, the lampreys migrated upstream along the rivers of the Baltic basin until they reached the water-parting line, followed by mostly downstream dispersal into rivers of the Caspian basin. Dispersal in the Volga River was similar, in accordance with the migration cycle of this opportunistic lamprey species.

The European river lamprey Lampetra fluviatilis (L., 1758) (Petromyzontidae) as a component of the Neva Bay bottom coenoses

The presence of larvae of the European river lamprey Lampetra fluviatilis was reported for the first time from in macrobenthic communities of the Neva Bay of the Gulf of Finland (St. Petersburg, Russia). It has been shown that ammocoetes inhabit several areas, at depths to 12 meters. Apart from ammocoetes, the communities with lamprey larvae contain abundant oligochaetes, bivalves, and less commonly chironomid larvae. At some sites, the number of larvae was up to 80 specimens/m2, while their biomass was over 90% of the total of the community. The abundance of macrozoobenthos in these sites is generally low (average abundance 190 specimens/m2, biomass – 70 g/m2), which is usual in autumn. Intestines of the ammocoetes constantly contained large quantities of diatoms representing common phytoplankton of the Gulf of Finland.

European river lamprey Lampetra fluviatilis L. in the Baltic and Caspian seas basins of Tver region

Представлена дополненная информация о распространении и условиях обитания речной миноги (Lampetra fluviatilis L.) на территории Тверской области. Ареал на территории области представляет собой сочетание исторического (водотоки бассейна Балтийского моря) и инвазионного (водотоки бассейна Каспийского моря) компонентов. Обоснована идея вселения миноги в систему р. Волга по системам искусственных судоходных каналов. Состояние популяций в Каспийском бассейне указывает на продолжающийся процесс освоения новых местообитаний. Additional information on the distribution and habitat of the European river lamprey (Lampetra fluviatilis L.) in the Tver Region is presented. The areal of the European river lamprey in the Region consists of the historical (watercourses of the Baltic Sea Basin) and invasive (watercourses of the Caspian Sea Basin) components. The idea of the lamprey invasion in the Volga River through the system of manmade shipping canals is substantiated. The condition of the lamprey’s populations in the Caspian Sea Basin indicates the ongoing process of the species expansion.