Patterns in circulation and transmission of marine bird parasites in High Arctic: a case of acanthocephalan Polymorphus phippsi (Palaeacanthocephala, Polymorphidae). P. 393-411.
This study, based on the materials on parasitic infection of marine birds and invertebrates in Frantz Josef Land (FJL) collected in 1991—1993, focussed on the acanthocephalan We identified this parasite, confirmed its species status and analysed its circulation and transmission patterns in high Arctic. The causes of its erroneous identification as P. minutus in several studies were also examined. In contrast to P. minutus, the transmission of P. phippsi is realized in marine coastal ecosystems. Its main intermediate host in the Arctic is the amphipod Gammarus (Lagnnogammarus) setosus, common in coastal areas of the shelf zone throughout the Arctic basin. P. phippsi population in FJL and the entire European Arctic is on the whole maintained by a single obligate final host, the common eider Somateria mollissima. Prevalence (P) of P. phippsi in this bird reached 100%, with the maximal infection intensity (Umax) of 1188 and the mean abundance (MA) of 492.1. Other species of birds found to be infected with P. phippsi (Arctic turn, black guillemot, purple sandpiper and several gulls) are facultative and/or eliminative hosts. The most heavily infected birds were Arctic terns (P = 72.7%, Umax = 227, MA = 47.1), which contained single mature acanthocephalans. For one of the FJL regions, infections flows of P. phippsi through various host categories were calculated. Involvement of birds unrelated to the common eider into the circulation of P. phippsi is facilitated by their feeding character in the Arctic. While coastal crustaceans are abundant, fish food is relatively scarce (polar cod, snailfishes), and so amphipods make up a considerable part of the diet of marine birds in FJL, if not most of it, as for instance in case of Arctic tern. This promotes an easy entry of the larvae of crustaceans-parasitizing helminthes (cestodes and acanthocephalans, including cystacanths P. phippsi) into non-specific hosts and opens broad colonization possibilities. Besides acanthocephalans, the phenomenon of non-specific parasitism has been shown for some cestodes circulating in the Arctic coastal ecosystems. Similar conditions for helminths transmission might have formed in marine coastal refugia during the glacial periods of late Pliocene—Pleistocene. According to the Arctic refugium hypothesis of Hoberg and Adams, this promoted parasitic colonization of phylogenetically distant hosts using similar foraging resources. Thus, present-day transmission patterns of helminthes in high Arctic can be, in a way, considered as a model allowing us to witness various stages of helminthes' speciation by host-switching.
Parasite fauna and structure of parasite component communities in the minnow Phoxinus phoxinus (Linnaeus, 1758) in an oil polluted waterstream. P. 412-427.
In June 1992 and July 1996, 238 minnow specimens of the 2+—3+ age were collected from 5 parts of the Kolva River and studied using the standard technique of the general parasitological dissection. Comparative analysis of parasite fauna and the structure of component parasite communities in the minnow from ecologically safe and variably polluted parts of the river was performed. The analysis had demonstrated that the increase in the water pollution by domestic wastewater, washings of fertilizers from agricultural fields and private country houses, cattle farm drains (Dorovskikh et al., 2005, 2008), and oil results in the change of dominant parasite species of the minnow, alteration of the sum of errors in the regression equation characterizing the spread of biomass values of the species forming the parasite community, changes in the «graphic» structure of the community, and alteration of the index DE'. It is proved, that the high concentration of nutrients has a destructive effect on natural systems, and, at the same time, causes the process of self-organizing, leading to the alteration of the community structure. As soon as even a small part of nutrients is stopped to come into the reservoir, and the quality of environment is restored, the community restores its structure.
Helminth fauna of wild boars (Sus scrofa L. 1758) in Azerbaijan. P. 428-432.
A total of 41 wild boar specimens, including 19, 10, 10, and 2 specimens from the Lesser Caucasus, the Greater Caucasus, the Kura-Araks lowland, and Lankaran natural region were studied. On the whole, 16 helminth species were revealed, including 2, 2, 1, and 11 species of trematodes, cestodes, acanthocephalans, and nematodes. The distribution of helminths in landscape-ecological zones of Azerbaijan is analyzed.
Relationships in the "northern fulmar (Fulmarus glacialis) - Tetrabothrius minor (Cestoda: Tetrabothriidae)" system: physiological aspects. P. 433-443.
Relationships between the northern fulmar (Fulmarus glacialis L., 1761) and cestodes Tetrabothrius minor Loennberg, 1893 (Cestoda: Tetrabothriidae) were studied. The results of calculation of the number of tapeworms in different parts (proximal, medial and distal) of bird intestines are represented. Parameters of protein metabolism in the northern fulmar and cestodes T. minor were investigated. Activity of proteases in different parts of northern fulmar intestine and in the strobila of T. minor was determined. Digestion processes occurring on digestive-absorptive surfaces of the intestine of the northern fulmar and of cestodes were studied. Biochemical indices of blood plasma of the northern fulmar were analyzed in relation to the intensity of invasion and the stage parasite maturation. The highest indices of the invasion of the northern fulmar with T. minor were recorded in the proximal part if the intestine. It was shown that the preferred localization of tapeworms in the proximal department of the intestine was determined by abundance of food and high activity of digestive enzymes in this place. Active hydrolysis of proteins in the intestine of the northern fulmar and on tegument surfaces of T. minor occurred mainly during the process of cavernous digestion. To a greater extent, the physiological state of the northern fulmar depended on the intensity of invasion and on the maturation stage of tapeworms.
Distribution of nadph-diaphorase activity in trematode cercariae. P. 444-452.
The presence and distribution of nitric oxide sinthase was studied in cercariae of trematodes from seven families using the nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemical method. The positive NADPH-d staining has been observed in nerve fibers in main nerve chords and in fibers running to eyespots (pigmented eyes) as well as in muscles of the oral and ventral suckers. The obtained data support an important role of the NO-signalling in the physiology of trematode cercariae.
Morphological diversity of fleas’ structures (Siphonaptera). Part 3: General characteristics and features of thoracic setation. P. 453-464.
The paper continues a series of publications (Medvedev, 2015a, b) devoted to the analysis of flea structural features. In the present publication, structural features of flea thoracic setation are analyzed for the first time. Six characters with 53 states in the structure of the chaetom of the pronotum, meso-, and metathoracic segments are distinguished. The author analyzes the cases of the formation of similar states stipulated by processes of reduction or, by contrast, by strengthening of the chaetom in fleas of separate genera belonging to different superfamilies in relation to the type or peculiarities of parasitism in different flea species. In spite of the presence of strong variability in arrangement and number of thoracic setae, some examples of marking of groups in the range families and superfamilies by certain states of the chaetotaxy of the pronotum and metepimera are revealed.
Index. P. 465-468.