New data on endobionts of Polyplacophora (Mollusca). P. 337-365.
The strictly marine benthic Polyplacophora serve as basibionts for a wide spectrum of endobiotic taxa. Here we present detailed observations of three yet unrecorded polyplacophoran — copepod endobioses, with highly modified females and males, which not fit into the current concept of the Chitonophilidae, to which we attribute them. Furthermore, presumed larvae of two of them show that even the ontogeny to the adult copepods is not strictly in line with the present understanding of this family. Range extension and additional morphological details are also presented for the chitonophilid copepod Tesonesma reniformis Avdeev and Sirenko, 1994. We also show the double infestation with chitonophilid copepods in a single basibiont, more specific the new record refers to a mesobiotic Ischnochitonika sp. and to one of the three endobiotic chitonophilids. Representatives of usually free-living nematodes are shown to occur also in two different basibionts. The last new record refers to a tentatively identified protist found in a North Pacific chiton. In an updated summary of yet known endobionts of Polyplacophora we not only refer to old literature records but indicate further records, which were out of focus of the present study. The compilation of 35 endobiotic records shows that only 3.1% of the currently known extant polyplacophorans, which represent 16 genera within nine families serve as basibionts for a wide range of phyla. The majority of records refer to Protista, followed by Nematoda and Crustacea. Only a few endobionts utilize the polyplacophoran's valves as habitat, the overwhelming data refer to soft tissue infestations. Although the polyplacophoran anatomy of the involved taxa do not allow a prediction of endobiotic trends, the present data show a lack of basibionts from the more primitive polyplacophoran order Lepidopleurida. It is assumed that the scarcity of studied material of this primary deep-water group is more likely an explanation than the anatomical peculiarities of these polyplacophorans. The capability of polyplacophora as basibionts is definitively underrepresented and bears a wide source for future parasitological studies.
The main patterns of long-term changes of the fauna of fish parasites in the Krasnoyarsk Reservoir. P. 366-381.
The paper describes changes in the parasite fauna of fishes of the Krasnoyarsk Reservoir determined by changes in the hydrological regime, extinction of native rheophylous host fish, impoverishment of benthic communities, and eutrophication of the reservoir. The number of parasite species with life cycle associated with benthos has strongly decreased. Only six species of Myxosporidia and a single species of Trematoda were revealed, whereas species of Acanthocephales were completely lacking. Triaenophorus nodulosus (Pallas, 1781) was frequently found. Dangerous to carp species parasites Ligula intestinalis (Linnaeus, 1758) and Digramma interrupta (Rudolphi, 1810) had appeared. Plerocercoids of Dibothriocephalus latus (Linnaeus, 1758) were absent in the Yenisei River, but at present a strong focus of dibothriocephalosis was formed in the Reservoir. This focus is the reason of the high degree of morbidity of the local population.
The first molecular genetic data on the Tetrathyridia of the genus Mesocestoides from the red-backed vole from Magadan Province. P. 382-394.
The first data on the study of tetrathyridia of the genus Mesocestoides Vaillant, 1863 (Cestoda, Cyclophyllidea, Mesocestoididae) from the red-backed vole Myodes rutilus (Pallas) from Magadan Province by molecular genetic methods are presented. The complete nucleotide sequence of the cytb mitochondrial gene and the partial sequence of the 12S rRNA gene Mesocestoides from the naturally infected host were obtained. The fragment of the nucleotide sequence of the 12S rRNA of the studied tetrathyridia is identical to those of GenBank, defined as M. lineatus (Goeze, 1782) from predatory mammals of Mongolia. The haplotypes of the 12S rRNA of Mesocestoides samples from the Magadan region and Mongolia, as well as the endemic species from Iceland M. canislagopodis (Krabbe, 1865) are in the same cluster.
Taxonomic diversity of myxosporean species (Myxozoa: Myxosporea) of fishes in the Lake Baikal basin. P. 395-402.
A checklist of myxosporean species parasitizing fishes in the Lake Baikal is given. The checklist includes host species names for the each parasite and authors of the first finding of the species. These species were found in 51 fish species. The list includes 72 species of myxosporidia. An analysis of the distribution of myxosporean species in the aquatic layers of the lake was performed.
Distribution and some biological features of ixodid ticks (Parasitiformes, Ixodidae) in Kuznetsk-Salair mountain area (Kemerovo Province, Russia). P. 403-416.
For certain regions including Kuznetsk-Salair mountain area, distribution of different species of ixodid ticks remains poorly studied. According to literary data and our studies, 11 of ixodid tick species were recorded from the territory of Kuznetsk-Salair mountain area. The following species of ticks were recorded from Gornaya Shoriya: I. lividus Koch, 1844, I. pavlovskyi (Pomerantsev, 1946), I. persulcatus Schulze, 1930, and Haemaphysalis concinna Koch, 1844. In Kuznetsk Depression, the following species were recorded: I. crenulatus Koch, 1844, I. apronophorus Schulze, 1924, I. lividus, I. pavlovskyi, I. persulcatus, H. concinna, Dermacentor reticulatus Fabricius, 1794, D. marginatus (Sulzer, 1776), D. silvarum Olenev, 1931, D. nuttalli Olenev, 1929. In Kuznetsk Alatau, the following tick species were noted: I. trianguliceps Birula, 1895, I. pavlovskyi, and I. persulcatus. Only 4 of all the mentioned species are really dangerous from the epidemiological point of view: I. persulcatus, I. pavlovskyi, D. reticulatus, and H. concinna, attacking their host in pastures. Other tick species are not dangerous, some because being nidicoles, some due to very low population density.
In memoriam of Natalia Aleksandrovna Filippova (1930—2018) — a brief scientific bibliography. P. 417-426.
Summary is absent.