The taxonomic diversity of the parasites of fishes in the Volga basin. III. Aspidogastrea and Trematoda

A checklist of Aspidogastrea and Trematoda parasitizing fishes in the Volga basin is given. The checklist includes host species names for the each parasite and data on the occurrence of parasites in different parts of the Volga basin. The data on trematodes from 69 fish species are presented. The list containes 107 species and 1 subspecies names of trematodes, and 1 species of Aspidogastrea. The family Diplostomidae is represented by the most number of species (22). Six species of trematodes (Amurotrema dombrovskajae, Sanguinicola skrjabini, Nicolla skrjabini, Plagioporus skrjabini, Apophallus muehlingi, Rossikotrema donicum) have been introduced into Volga River along with aclimatizated fishes or penetrated into its basin by self-migration to new water bodies.     

Distribution of trematodes of the family Prosthogonimidae in river and lake ecological systems in the south of the Western Siberia

The results of long-term investigations (1994-2003) of an infection rate of trematodes of the family Prosthogonimidae in the first intermediate hosts (snails of the family Bithyniidae) and in the final hosts (birds) from a basin of the Chany Lake (Western Siberia) are discussed. A total of 1824 specimens of Bithynia tentaculata (L., 1758) and 7166 specimens of Opisthorchophorus troscheli (Paasch, 1842) have been collected from eight rivers and two lakes in the south of the Western Siberia. Data of incomplete helminthological dissection of 225 young water-fowl of 18 species were analyzed. Birds were obtained in July, August and September, 1996-2003 from the Chany lake basin. Maritas of the trematode family Prosthogonimidae were revealed in bursa Fabricii (26.12%) of seven bird species of two orders (Anseriformes and Gruiformes): Grey Lag-Goose Anser anser (L.) (Infection rate-28.6% +/- 12.1), Mallard Anas platyrhynchos L. (27.5% +/- 6.2), Shoveler--A. clypeata L. (22.2% +/- 13.9), Pochard Aythya ferina (L.) (51.7% +/- 9.3), Coot Fulica atra L. (28.6% +/- 5.6), Tufted Duck A. fuligula (L.) (1 case), Wigeon A. penelope L. (1 case). Average intensity of invasion is 5.8 marita specimens per infected bird. The maximal number of parasites (37 maritas), and also the highest average intensity of invasion are recorded for the Coot. The 342 maritas of the family Prosthogonimidae belong to three species: Prosthogonimus ovatus (Rud., 1803) (49.7%), P. cuneatus (Rud., 1809) (32.8%) and Schistogonimus rarus (Braun, 1901) (14.6%); these trematode species have been recorded in 35, 12 and 8 bird species, respectively. Grey Lag-Goose, Shoveler, Pochard and Tufted Duck are new host records for P. cuneatus in for Western Siberia. Parthenitae of trematodes (Prosthogonimidae) were revealed from eight populations of bithyniid snails. The infection rate of the trematodes (parthenitae and cercariae) in population of bithyniid snails from lake ecological system varied 6.55-54.4%, and in river ecological systems in was 0.6-4.2 %. The infection rate of trematodes (parthenitae and cercariae) of the first intermediate hosts was 2.64% that is significantly lower than that of the final hosts from the Chany Lake basin. Both O. troscheli and B. tentaculata were noted as the first intermediate hosts of prosthogonimid trematodes of three species: P. ovatus, P. cuneatus and S. rarus. All three species of trematode were found in three water reservoirs: Ob River (B. tentaculata), Kargat River (O. troscheli) and Chany Lake (O. troscheli). Thus it is found out that 39 bird species can be the final hosts of prosthogonimid trematodes. About a quarter of nestlings is infected with these trematodes. The infection rate of parthenitae in snails from the lake ecosystems is significantly higher than in the river ecosystems.     

Nonindigenous invertebrates in the periphyton and benthos of upper Volga reservoirs: A review

The mechanisms, ways, and traits of acclimatization of aquatic animals within and outside their historical ranges are reviewed. It is shown on the example of the upper Volga basin that formation still continues of the fauna in reservoirs that began after their impoundment during 1930s–1950s. It is also shown that Ponto-Caspian invaders and intentionally introduced Baikal amphipods play a great role in this process. The data on the traits of biological cycles of mass nonindigenous invertebrates in upper Volga reservoirs are presented. The main ecological factors facilitating expansion of new species in reservoirs are demonstrated. It is shown that the assessment of the functional role of dreissena in waterbodies should include determination of the abundance of the larvae of this species in plankton.     

Occurrence and parasite fauna of Dressena bugensis in the Rybinsk reservoir

The zebra mussel Dreissena bugensis (Andrusov), a representative of mollusc fauna in the Dnieper-Bug estuary, have been found for the first time in the Rybinsk reservoir (the Volga reach, Shumorovka River). In pericardial and mantle cavities and inner organs of molluscs the following parsites have been found: Aspidogaster limacoides, Caspiobdella fadejevi, Helobdella stagnalis, eggs of the water mites of the genus Unionicola, and representatives of nonspecific saprotrophic fungi of the genus Acremonium. It is shown that composition of parasites and free-living organisms in D. bugensis is similar to that in D. polymorpha.     

Invasion of fish with leeches (Fam. Piscicolidae) in reservoirs of the Volga river

It is shown for the first time that during 50 years of the Rybinsk reservoir's existence the abundance of parasite leeches (Piscicolidae) has increased, and the species composition has become richer. In 70 the leech Caspiobdella fadejewi (Epstein) was registered here as a mass species. This species became a real competitor to Piscicola geometra (L.) inhabiting the Volga river in all times. In early '90s the leech Acipenserobdella volgensis (Zykoff) appeared in the Rybinsk reservoir. Till 1987 this species was not found to the north from the Kuibyschev reservoir. An increase in number of fish leeches and an extension of their specific composition occurred not only in the Rybinsk reservoir but in the other reservoirs of the Volga cascade as well.     

History of fish parasitic fauna formation in water reservoirs of European North

The fauna of fish parasites in water bodies of the European North was formed in the Holocene by species immigrated from adjacent regions. The Volga River basin played a very important role in the history of the formation of fauna in water bodies of the European North (North Dvina and Onega river basins, Onega and Ladoga lakes), because there were wide connections between them in the postglacial period.     

Taxonomic diversity of parasites from agnathans and fishes in the Volga basin. II. Parasitic Coelenterata and Monogenea

A checklist of the Monogeneans and Coelenterates parasitizing fishes in the Volga River basin is given. The list of hosts with the data on their occurrence in different areas of the Volga River basin is provided for each parasite species. The data on the parasites from 46 fish species are presented. The checklist includes 139 species and 6 taxa of subspecific rank. 9 species (Dactylogyrus aristichthys, D. ctenopharyngodonis, D. hypophthalmichthys, D. lamellatus, D. nobilis, D. suchengtaii, Pseudodactylogyrus bini, P. microrchis, and Eudiplozoon nipponicum) were introduced into the Volga River basin accidentally together with the Far Eastern fish species during the process of their naturalization.     

Helminth parasites of the western willet, Tringa semipalmata inornata, from Montana and Texas with a checklist of helminth parasites

In total, 26 western willets, Tringa semipalmata inornata , were examined for helminth parasites, including 8 spring migrating hosts from the Chihuahua Desert, Rio Grande Valley, Texas, and 18 post-breeding hosts from east central Montana. Sixteen species of helminth parasites were present in component communities for both spring migrants and post-breeding birds. There were 9 species of trematodes, 2 cestodes, and 5 of nematodes, with a total of 1,593 individual specimens (X = 99.6, ±SE = 57.9, M = 9) present in migrating willets, and 5 species of trematodes, 8 cestodes, and 3 nematodes for a total of 1,148 individual specimens (X = 71.8, ±SE = 34.4, M = 12) present in post-breeding hosts. Species richness in infracommunities ranged from 2 to 10 (X = 5.1, ±SE = 0.95, M = 5.3) for spring migrants, and from 1 to 4 (X = 2.8, ±SE = 0.26, M = 3) for post-breeding birds. Diversity and evenness were 0.72 and 0.23 for spring migrants and. 0.62 and 0.17 for post-breeding hosts. Trematodes were the dominant taxa in spring migrants and cestode taxa in post-breeding hosts. Helminths with marine-associated life cycles were present in larger numbers in spring migrants from the Rio Grande Valley (11 of 16 species) than in post-breeding hosts from Montana hosts (4 of 16 species). The higher number of marine species in spring migrants was probably related to their more recent association with a marine habitat. Several species of Anomotaenia were major contributors to the component communities in both localities. Four species of nematodes with large prevalence, i.e., Schistorophus skrjabini, Sciadiocara umbellifera, Skrjabinoclava inornatae, and Sobolivicephalus lichtensfelsi, observed in spring migrants from the Rio Grande Valley were absent from Montana hosts. There was only a 2% similarity between the Rio Grande Valley and Montana. All helminth species, except for the possibility of Anomotaenia spp., were generalists. A checklist of helminth parasites of the willet is included.     

闽江流域生态安全格局及其生态保护修复措施

流域及其生态环境问题受到国内外的广泛关注,我国面临的流域生态环境问题突出亟待解决,体现流域生态系统完整性的山水林田湖草生命共同体理念对我国流域生态保护修复工作具有重要意义。以福建省山水林田湖草生态保护修复试点的工程区——闽江流域为例,在介绍其生态环境特征的基础上,通过梳理分析,根据区域生态功能的重要性构建“一江一带一区一屏”的闽江流域总体生态安全格局,面临的主要生态环境问题包括闽江水环境污染、流域岸带水土流失、矿区生态破坏、森林屏障和生物多样性退化等一系列威胁;分析提出了闽江水环境综合治理、干支流沿岸带水土流失防治、矿区废弃土地修复、武夷山地等重要生态屏障森林和生物多样性保护等主要任务及相应工程措施,体现了流域整体性、系统性的保护修复需求和内在逻辑;讨论了监测、评价等保障措施,为改善闽江流域生态系统和开展山水林田湖草生态保护修复工程提供科学依据和实践经验。     

The distribution and incidence of larval trematodes in the freshwater fauna of the Wentloog level, South Wales

The Wentloog level, in South Wales, is a low-lying coastal plain dissected by a network of drainage channels. The latter contain a rich aquatic invertebrate fauna which harbour a wide range of larval digenetic trematodes. Few of the host species examined were not infected with larval trematodes. Miracidia together with their associated sporocysts, rediae and cercariae were more host specific than metacercariae but many of the miracidia which developed in pulmonate molluscs could do so in more than one genus. Metacercarial host specificity is less rigid, and usually species are only restricted to members of one phylum although several were found which could develop in two or more phyla. Most larval stages showed some host preference when they occurred in several host species and this was attributed to ecological or physiological factors or to mechanical barriers. Seasonal variation of infection rate occurs in all larval stages: infection with developing cercariae showed peaks during June and August, but metacercarial infection rates varied according to the host. In molluscs there may be two peaks of infection with metacercariae (as in the cercarial stages), but for many arthropods infections show a gradual increase through the year. The factors mainly responsible for these seasonal changes are considered to be the life-cycle of the intermediate hosts and the environmental temperature, the latter acting on the rate of development of the trematodes. Rainfall, and patterns of egg production of adult trematodes in the definitive hosts are also important.     

Golden algae (Chrysophyta) in plankton of the Volga River reservoirs: Taxonomic structure,dynamics of diversity,and abundance

Long-term (1953–2004) published and original data on the taxonomic composition and ecological and geographical characteristics of planktonic crysophytes have been systematized and the degree of similarity of the crysophyte flora in nine reservoirs of the Volga River basin has been assessed. Patterns of changes in the specific species richness and biomass of golden algae along the longitudinal profile of the Volga River reservoirs are identified. The relationship between species richness and some abiotic and biolimnological parameters has been analyzed. The decline in diversity and biomass of golden algae in direction from the Upper to the Lower Volga in accordance with the geographical zoning is revealed. The long-term dynamics (1954–2011) of the species richness, abundance, and biomass of golden algae has been analyzed. A positive correlation between the diversity and biomass of golden algae and the amount of precipitation and water temperature is demonstrated.     

The taxonomic diversity of the parasites of agnathans and fishes in the Volga basin. I. Parasitic protozoa (Protozoa)

A checklist of protozoa parasitizing fishes in the Volga basin is given. The checklist includes host species names for the each parasite and data on the occurrence of parasites in different parts of the Volga basin. The data on parasitic protozoa from 52 fish species are presented. The list containes 224 species and 10 subspecies names of the parasites. 9 species (Trypanosoma gracilis, Eimeria cheni, E. sinensis, Zschokkella striata, Chloromyxum cyprini, Myxobolus amurensis, M. driagini, M. pavlovskii, and Balantidium ctenopharyngodoni) were introduced into the Volga basin from the Amur basin along with acclimatizated fishes.     

Comparative study of helminth parasites of fishes from the Mogi Guassu river, collected during expeditions between 1927 and 1985

This paper concerns the parasitism of Nematoda, Trematoda, Acanthocephala and Cestoda from 1027 fishes of 45 species from Mogi Guassu river, examined in the years 1927, 1946, 1947, 1962, 1983 and 1985 as a contribution to the knowledge of the parasitological fauna in 58 years. Thirty two species of nematodes, 21 of trematodes, 3 of acanthocephalans and 2 of cestodes are reported. New hosts are presented for the nematodes Cucullanus pinnai, Spirocamallanus inopinatus and Travnema travnema, for the trematode Pararhipidocotyle jeffersoni and for the acanthocephalan Gorytocephalus spectabilis. New measurements for the trematode Creptotrema lynchy, tables, graphics and a list of the examined hosts with their parasites are presented.     

The results of a study of the species composition of fish parasites in the river basins of northeastern European Russia. Leeches (Hirudinea), mollusks (Mollusca), crayfish (Crustacea) and arachnids (Arachnida)

The report contains the results of faunistic study of parasitic Hirudinea, Mollusca, Crustacea and Arachnida occurring on fishes in the region of the S. Dvina, Mezen' and Pechora river basins. The parasite fauna in the first basin is represented by 3 species of leeches, 4 species of molluscs, 13 species of crustaceans and 1 species of water mites, in the second basin--4, 1, 11, 0; in the third basin--2, 7, 7, 1 species respectively. Total number of parasites in the region investigated: 4 leech species, 5 molluscs species, 16 crustacean species and 1 water mite species.     

Macroinvertebrates: Caspian invaders in the reservoirs and rivers of the Kama River basin

The character of the distribution of Caspian invaders in the Kama River basin and the current state of their development in the Kama water reservoirs were studied. The role of invaders in the structure and functioning of bottom communities is reviewed.     

The use of fluorescent fatty acid analogs as labels in trematode experimental infections

We examined the utility of fluorescent fatty acid analog dyes for labeling larval trematodes to use in experimental infections. Our goals were to identify two dyes that label larval trematodes belonging to the species Maritrema novaezealandensis and Coitocaecum parvum, determine if the dyes influence survival and infectivity of larval trematodes and/or host mortality, and if larval trematodes labeled with alternative dyes could be distinguished post-infection. The two dyes tested, BODIPY FL C₁₂ and BODIPY 558/568 C₁₂, successfully labeled all treated larval trematodes, did not influence cercariae survival or infectivity, and did not influence host mortality in either host-parasite system. All larval parasites were fluorescent and distinguishable after 5 days in amphipod intermediate hosts. In addition, larval Acanthoparyphium sp. were strongly fluorescent with both dyes after 5 weeks within cockle hosts. This method should be extremely useful for experimental studies using trematode-host systems as models for addressing a range of ecological and evolutionary questions.     

First Finding of Ornithodiplostomum scardinii (Schulman, 1952) Sudarikov et Kurotschkin, 1968 (Trematoda,Diplostomidae) in Rybinsk Reservoir

During a parasitological survey of nonnative fish species—rudd Scardinius erythrophthalmus—in the Rybinsk Reservoir, the metacercariae Ornithodiplostomum scardinii were found in its brain. This is the first find of this helminth in the Upper Volga basin. The rudd was infected with the prevalence 31.3%, with an intensity of 1–12 parasites per fish. Data on the current distribution of the trematode O. scardinii in the Volga River basin are provided.     

Taxonomic diversity of parasites in agnathans and fishes from the Volga River basin. VI. Acanthocephala, Hirudinea and Bivalvia

The checklist of Acanthocephala, Hirudinea, and Bivalvia parasitizing agnathans and fishes in the Volga River basin is presented. Hosts and areas of distribution are indicated for each parasites species. The checklist includes 10 species of acanthocephalans, 7 species of leeches, and 9 species of Bivalvia (at the glochidium stage) from 45 fish species. None of the given parasite species is alien for the Volga River basin.     

Fish parasites as bioindicators of the pollution of bodies of water]

The paper presents the results of studies on the effect of wastes of the Cherepovets iron-and-steel works containing phenol, naphthaline and oil products on fish parasites of the Sheksna part of the Rybinsk water reservoir (the Volga river system). It has been shown that the number of highly sensitive ectoparasites of Abramis brama (Protozoa, Dactylogyrus monogeneans, Ergasilus sieboldi crustaceans and Caspiobdella fadejewi leeches) considerably decreases in the zone of pollution. It has been first suggested to use Diplozoon paradoxum and Caryophyllaeus laticeps, parasites of bream highly resistant to toxic effect, the number of which considerably increases in the zone of pollution, as indicators of anthropogenic pollution and ecological state of a water body. Among diplozoons there have been first discovered individuals having structural anomalies (reduction of the attachment organs, violation in the symmetry of arrangement and number of valves) that serves as evidence of mutagenic effect of toxic substances of polluted waters on morphogenesis of the parasite.     

Biomonitoring Heavy Metal Pollution Using an Aquatic Apex Predator,the American Alligator,and Its Parasites

Monitoring the bioaccumulation of chemical elements within various organismal tissues has become a useful tool to survey current or chronic levels of heavy metal exposure within an environment. In this study, we compared the bioaccumulations of As, Cd, Cu, Fe, Pb, Se, and Zn between the American alligator, Alligator mississippiensis, and its parasites in order to establish their use as bioindicators of heavy metal pollution. Concomitant with these results, we were interested to determine if parasites were more sensitive bioindicators of heavy metals relative to alligators. We found parasites collectively accumulated higher levels of As, Cu, Se, and Zn in comparison to their alligator hosts, whereas Fe, Cd, and Pb concentrations were higher in alligators. Interestingly, Fe levels were significantly greater in intestinal trematodes than their alligator hosts when analyzed independently from other parasitic taxa. Further analyses showed alligator intestinal trematodes concentrated As, Cu, Fe, Se, and Zn at significantly higher levels than intestinal nematodes and parasites from other organs. However, pentastomids also employed the role as a good biomagnifier of As. Interestingly, parasitic abundance decreased as levels of As increased. Stomach and intestinal nematodes were the poorest bioaccumulators of metals, yet stomach nematodes showed their ability to concentrate Pb at orders of magnitude higher in comparison to other parasites. Conclusively, we suggest that parasites, particularly intestinal trematodes, are superior biomagnifiers of As, Cu, Se, and Zn, whereas alligators are likely good biological indicators of Fe, Cd, and Pb levels within the environment.