Invasion of the European River Lamprey Lampetra fluviatilis in the Upper Volga

The European river lamprey came to the Upper Volga from the Baltic Sea most probably via a system of shipways developed in the 18th and 19th centuries. The Vyshnii Volochek, Tikhvin, and Mariinskaya water systems are possible invasion pathways for this species. Dispersal and colonization of the Caspian Basin was likely a combination of upstream and downstream migrations. Analysis of museum and our own samples showed that lamprey possibly migrated upstream (for spawning) along rivers of the Baltic Basin until they reached the watershed boundary from which they could disperse downstream (in the juvenile period) into rivers of the Caspian Basin. Dispersal in the Volga River could occur in accordance with the migration cycle of this opportunistic lamprey species and lead to the present distribution. Key features (dentition and number of trunk myomeres) showed that lamprey from the studied area are similar to lampreys from the Baltic basin, although specimens in each population have their own peculiarities in morphology (size and coloration). Genetic data (Cyt-b) support the idea of a relatively recent invasion of lamprey into the Upper Volga. The haplotype, found in three rivers, is one of the most widespread in Europe and is found along the supposed route of invasion.

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.

A handy trap for capturing of the adult river lamprey in streams

In the Baltic Sea Basin, the river lamprey, Lampetra fluviatilis (L.), is still important to commercial fishing; however, the species is on the decline, especially in the southern part of the catchment area. At present, the river lamprey is protected by European law that requires monitoring its stocks. This article describes a convenient trap for catching adult river lamprey in streams. The gear is a small fish-pot or hoop-net with two chambers. Operating the trap is very simple, and tests indicated its usefulness for monitoring ascending river lamprey. Thus, this trap design is recommended as a standard tool for use in the future, especially since there is a lack of commercial fishery data.

An evolutionarily ancient mechanism for regulation of hemoglobin expression in vertebrate red cells

The oxygen transport function of hemoglobin (HB) is thought to have arisen ∼500 million years ago, roughly coinciding with the divergence between jawless (Agnatha) and jawed (Gnathostomata) vertebrates. Intriguingly, extant HBs of jawless and jawed vertebrates were shown to have evolved twice, and independently, from different ancestral globin proteins. This raises the question of whether erythroid-specific expression of HB also evolved twice independently. In all jawed vertebrates studied to date, one of the HB gene clusters is linked to the widely expressed NPRL3 gene. Here we show that the nprl3-linked hb locus of a jawless vertebrate, the river lamprey (Lampetra fluviatilis), shares a range of structural and functional properties with the equivalent jawed vertebrate HB locus. Functional analysis demonstrates that an erythroid-specific enhancer is located in intron 7 of lamprey nprl3, which corresponds to the NPRL3 intron 7 MCS-R1 enhancer of jawed vertebrates. Collectively, our findings signify the presence of an nprl3-linked multiglobin gene locus, which contains a remote enhancer that drives globin expression in erythroid cells, before the divergence of jawless and jawed vertebrates. Different globin genes from this ancestral cluster evolved in the current NPRL3-linked HB genes in jawless and jawed vertebrates. This provides an explanation of the enigma of how, in different species, globin genes linked to the same adjacent gene could undergo convergent evolution.