Irina A. Kaygorodova

New sperm types in Naididae and Lumbriculidae (Annelida: Oligochaeta) and their possible phylogenetic implications

The sperm ultrastructure of three Naididae (Paranais frici, P. litoralis and Stylaria lacustris) and two Lumbriculidae (Rhynchelmis brachycephala and R. alyonae) is decribed to supply spermatological evidence towards a better understanding of the phytogeny of the two families. Naidid spermatozoa were found to be similar to one another, particularly with regard to the acrosome (with the acrosome tube bent to one side), and the shape and number of mitochondria. The various morphological characters do not militate against the previously proposed inclusion of naidids within the Tubificidae. The two lumbriculid species examined showed a characteristic conical indentation at the apex of the nucleus, a feature up to now described only in Branchiobdellida, an annelid group with possible affinities to Lumbriculidae.

Leech-like parasites (Clitellata, Acanthobdellida) infecting native and endemic eastern Siberian salmon fishes.

Salmonoid fish bdellosis is caused by leech-like ectoparasites in the monogenetic order Acanthobdellida. Although Acanthobdella species have been known to infect several threatened species in Eurasia, little is known about their ecology and epidemiology. In this paper, we report on the mass affection (up to 70.7%) of fish in lower course of the Chechuj River, a right tributary of the Lena and provide information on finding Acanthobdella peledina on two of six salmonoid fish species inhabiting there: lenok and grayling. New and more specific data on morphological peculiarities and feeding strategy were obtained. The ratio of body length to width in studied acanthobdellid collection is significantly less than one provided for the A. livanowi and the rest A. peledina from other water systems of Eurasia. Biology and lifestyle of the parasite population are revealed for the first time.

Molecular phylogenetic study of the systematic position of Baikalian oligochaetes in Clitellata

Phylogenetic relationships within the class Clitellata were examined using partial nucleotide sequences of the nuclear 18S ribosomal RNA gene. In the analysis, the already determined sequences for the individual species representing the class members Hirudinea, Acanthobdellida, Branchiobdellida, and Oligochaeta were included. Furthermore, newly determined sequences of the thirteen representatives of the family Lumbriculidae, including 12 Baikalian endemic species, were analyzed. The hypothesis on the close relatedness of these four groups of Clitellata was supported. Leeches, branchiobdellids, and lumbriculids form three independent parallel branches of evolution. These results were consistent with the hypothesis on the role of the family Lumbriculidae as a connecting link, or the transition form between the parasitic and free-living groups of Clitellata. At the same time, these data refute the suggestion that Lumbriculidae could be the ancestral lineage of other Oligochaeta. Moreover, polymorphic group of Baikalian lumbriculids clustered independently from the other representatives of the family, pointing to the uniqueness of the Baikalian fauna of oligochaetes, which was formed within relatively closed system of this ancient lake.

The formation of a fouling community on artificial substrate in Lake Baikal

The development of a fouling community at the surface of an artificial substrate in the littoral zone of Lake Baikal was studied. This epibenthic community was composed of 23 diatom species and 57 invertebrate species. The core community consisted of molluscs and caddisflies feeding mostly on diatoms. In Lake Baikal a fouling community develops in a sequence similar to marine environments.

New Records of Lake Baikal Leech Fauna: Species Diversity and Spatial Distribution in Chivyrkuy Gulf

The study of several Lake Baikal leech collections offered us the possibility to determine species diversity in the Chivyrkuy Gulf, the biggest one in the lake. As a result, the first information on the Chivyrkuy Hirudinea fauna (Annelida, Clitellata) has been revealed. There are two orders and four families of leeches in the Chivyrkuy Gulf: order Rhynchobdellida (families Glossiphoniidae and Piscicolidae) and order Arhynchobdellida (families Erpobdellidae and Haemopidae). In total, 22 leech species and 2 subspecies belonging to 11 genera were identified. Of these, 4 taxa belong to the family Glossiphoniidae (G. concolor, A. hyalina, A. heteroclita f. papillosa, and A. heteroclita f. striata) recorded in Baikal for the first time. Representatives of 8 unidentified species (Glossophinia sp., Baicaloclepsis sp., Baicalobdella sp., Piscicola sp. 1, Piscicola sp. 2, Erpobdella sp. 1, Erpobdella sp. 2, and Erpobdella sp. 3) have been also recorded. The checklist gives a contemporary overview of the species composition of leech parasites, their hosts, and distribution within the Chivyrkuy Gulf. The analysis of spatial distribution has shown that the leech species diversity is correlated with the biological productivity of the bay. The most diverse community of leech species is detected in the eutrophic zone of the lake.

Genetic Diversity of Freshwater Leeches in Lake Gusinoe (Eastern Siberia, Russia)

The study of leeches from Lake Gusinoe and its adjacent area offered us the possibility to determine species diversity. As a result, an updated species list of the Gusinoe Hirudinea fauna (Annelida, Clitellata) has been compiled. There are two orders and three families of leeches in the Gusinoe area: order Rhynchobdellida (families Glossiphoniidae and Piscicolidae) and order Arhynchobdellida (family Erpobdellidae). In total, 6 leech species belonging to 6 genera have been identified. Of these, 3 taxa belonging to the family Glossiphoniidae (Alboglossiphonia heteroclita f. papillosa, Hemiclepsis marginata, and Helobdella stagnalis) and representatives of 3 unidentified species (Glossiphonia sp., Piscicola sp., and Erpobdella sp.) have been recorded. The checklist gives a contemporary overview of the species composition of leeches and information on their hosts or substrates. The validity of morphological identification of each taxon has been verified by phylogenetic approach with a molecular marker adopted for a DNA barcoding of most invertebrates.

First Records of Potamic Leech Fauna of Eastern Siberia, Russia

We studied the fauna of leech and leech-like species inhabiting main water streams of Eastern Siberia and its tributaries, which are attributed to Lake Baikal basin and Lena River basin. Here we present their list for the first time. This study was mainly aimed for free-living parasitic and carnivorous leeches whereas piscine parasites were not included specially. In total, the potamic leech fauna of Eastern Siberia includes 12 described species belonging to 10 genera. Representatives of three unidentified species of two genera Erpobdella and Barbronia have been also recorded.

New information on the distribution pattern of Acanthobdella peledina (Annelida, Acanthobdellida) in Eastern Siberia

The Acanthobdellida is a group of annelid parasites of fish, which are restricted to subarctic parts of the Northern Hemisphere. These ancient worms arouse the interest of the scientific world due to their mosaic combination of (1) primitive oligochaetous characters (e.g. the presence of setae on the very anterior segments, a lateral nerve system and a metameric coelomic cavity around the intestinal canal) and (2) evolutionarily advanced hirudinean ecological and morphological features (e.g. suckers and parasitic lifestyle), attesting to their intermediate role between Oligochaeta and Euhirudinea (i.e. leeches with setae).

The first data on species diversity of leeches (Hirudinea) in the Irtysh River Basin, East Kazakhstan

The Irtysh River is one of the major waterways of the Republic of Kazakhstan. The river originates in the territory of Mongolia and China, flows through the East Kazakhstan and falls into the Ob River in the Western Siberia of Russia. The Kazakhstan section of the river, with length of 1698 km and water resources about 43.8 km3 (Dyusebaeva 2012), is situated on the border of the West Siberian Plain, the Altai Mountains and the Kazakh Uplands. As the river crosses various natural zones, characteristics of its hydrological regime is very diverse. In the south, in the area of Ust-Kamenogorsk, the valley of the Irtysh extends. In the upper reaches up to the city of Semey (formerly Semipalatinsk), the river is surrounded by plain and mountain landscapes. Downstream from Semey, the Irtysh enters the West Siberian Plain and flows to north-west through dry steppes. The riverbed is unstable: sometimes it is very tortuous, sometimes it is broken into branches, and, there are a lot of sand spits. The hydrological level of the Kazakhstan part of the Irtysh River is regulated with the cascade of storage reservoirs near the towns Bukhtarma, Ust-Kamenogorsk and Shulbinsk.

The present state of the leech fauna (Annelida, Hirudinea) in the Upper Irtysh cascade of water reservoirs.

Abstract Hirudinea is a small and ecologically important group of aquatic organisms. However, up to date, the leech fauna of Kazakhstan is poorly studied. The presence of large under-collected areas, such as the Upper Irtysh basin, makes biodiversity studies concerning these invertebrates from Kazakhstan relevant. In this paper, the latest information on species diversity of the freshwater hirudofauna of the Upper Irtysh cascade of water reservoirs, the Kazakhstan part of Irtysh River, is presented. It includes 10 free-living and parasitic species, of which 7 and 9 inhabit the Shulbinsk and the Bukhtarma reservoirs, respectively. These species belong to 2 orders, 3 families and 6 genera. The faunal list highlights four potentially new morphological species (Alboglossiphonia sp., Erpobdella sp., Piscicola sp. 1 and Piscicola sp. 2). Besides them, another three species Erpobdella vilnensis, Helobdella stagnalis and Theromyzon tessulatum recorded for the first time in the area. The exact systematic position is stated for all leech taxa. Each species from the list accompanied with information on taxonomic synonymy, data on its geographic distribution, and brief summary of morphological and ecological characteristics.