Morphological variation and taxonomic status of Altai osmans, Oreoleuciscus, from the upper reaches of the Ob River system

The morphology of the endemic Altai osmans Oreoleuciscus spp. (Cyprinidae), from headwaters of the Ob tributaries in the Altai Republic (Russia), Terekhol Lake in the Tuva Republic (Russia), and the Chovd Gol River drainage and related bodies of water (Mongolia), where they are one of only four fish species occurring in most bodies of water were examined. Their high degree of morphological variation makes species determination problematical. Analysis of six meristic counts and principal component analysis (PCA) of 21 morphological measurements discriminated two species, Oreoleuciscus potanini and O. humilis . The results suggest that only O. potanini occurs in the upper reaches of the Ob system. The systematics and biogeography of Oreoleuciscus are discussed.     

On estimation of phenetic relationships of Altai Osmans (<Emphasis Type="Italic">Oreoleuciscus</Emphasis>, Cyprinidae) from three lakes in Mongolia by skull characters

By four meristic and 14 morphometric characters of the skull the phenetic relationships of Altai Osmans of the genus Oreoleuciscus from lakes Ust-Nur (the Selenga Basin), Sangiyn-Dalai-Nur (the Khangai Highland), and Orog-Nur (Lake Valley) are estimated. Principal components analysis is performed. No interpopulational differences by the set of meristic characters are found. By the set of morphometric characters the specimens from Lake Ust-Nur in the space of principal components are separated from specimens from two other lakes while the distributions of specimens from Lake Sangiyn-Dalai-Nur and Orog-Nur overlap. With consideration of estimates of similarity in the structure of interpopulational differences it is assumed that separation of the phyletic line common for populations of lakes Ust-Nur and Orog-Nur from the phyletic line of population of Lake Sangiyn-Dalai-Nur preceded separation of phyletic lines of populations from lakes Ust-Nur and Orog-Nur.     

New host species and new distribution areas of <Emphasis Type="Italic">Salmincola lavaretus</Emphasis> (Copepoda: Lernaeopodidae): A parasite of coregonid fishes of Siberia

Data on the infestation of certain fish species by the parasitic copepod Salmincola lavaretus are presented for the first time. The infested fish species included Bauntovsky whitefish (Coregonus baunti), an endemic species from the Maloye and Bolshoye Kapylyushi lakes; Siberian whitefish (C. pidschian) and Siberian cisco (C. sardinella) from Bolshoye Kapylyushi Lake and Baunt Lake, which belong to the Tsypo-Tsypikan lake system (the Lena River basin, Transbaikalia); and Teletsky whitefish (C. lavaretus natio smitti) from Teletskoe Lake (the Ob River basin). Previously, S. lavaretus had been described as a parasite of Baikal omul (C. migratorius) and Baikal whitefish (C. baicalensis) from Baikal. The taxons of S. longimanus complex (S. longimanus, S. l. sibirica, S. svetlanovi, and S. lavaretus)—parasites of nasal fossae of grayling and coregonid fishes—were registered in the lakes of the Lake Baikal basin (Lake Baikal and Khovsgol Lake), the Lena River, the Yenisei and the Ob rivers (the largest rivers of the Arctic zoogeographic province), and the Kobdo River (the Western Mongolian province). It was assumed that S. longimanus complex is more widely distributed in the water bodies of the Arctic zoogeographic province of the Palearctic.     

The parasite fauna of characids' (Osteichthyes: Characidae) Anambra River, Nigeria

Baseline information on the parasites of frequently caught species of the characids namely Hydrocynus vittatus , Alestes baremoze , Brycinus macrolepidotus and Brycinus leuciscus was investigated in Anambra River from August 2004 to July 2005. The parasites recovered were the Myxosporid, Myxobolus sp (Protozoa), Polyopistocotylids, Diplozoon ghanense and Neodipolzoon polycotyleus (Monogeneans), the Caryophyllid Caryophylleus sp (Cestoda) and Rhabdochona sp (Nematoda). The prevalence of Caryophylleus sp in B. macrolepidotus (14.2%) and A. baremoze (8.1%) as well as Rhabdochon sp and Myxobolus sp in H . vittatus (9.6% and 7.8% respectively) was relatively high (>7.0%); while the other parasite species Myxobolus sp in B. leuciscus (2%), D. ghanense in B. macrolepidotus (1.9%) and N. polycotyleus in A. baremoze (1.9%) had a much lower prevalence (2.7%). Distribution of parasites was clearly seasonal. Dissolved oxygen (8.0–14.0) mg l⁻¹ and pH (5.5–7.0) influenced the occurrence of the parasites whereas temperature (20.1–27.5 DC) showed no much effect.     

Phylogeography of Altai osmans (Oreoleuciscus sp., Cyprinidae, Pisces) based on sequence variation of the mitochondrial DNA cytochrome b gene

Representatives of the genus Oreoleuciscus (Altai osmans) from the water bodies of Western Mongolia were examined for sequence polymorphism of the mitochondrial DNA fragment containing the cytochrome b (Cyt-b) gene. A total of 17 sequence variants (haplotypes) were discovered, which formed two clusters, A and B, with nonoverlapping geographic localization. Cluster A included haplotypes of Altai osmans from the Valley of Lakes water bodies. Cluster B consisted of two subclusters, the first of which (B1) united sequence variants of the populations from Hollow of the Great Lakes and the lakes of the Great Altai Range. The second subcluster (B2) was formed by the haplotypes originating from the Hollow of the Lake Uvs, some isolated lakes of the Northwestern Khangay region, and the water bodies of the Arctic Ocean Basin (basins of Selenga and Orchon rivers). Based on the genetic divergence estimates and the radiation time of genetic geographic groups identified, the existence of three allopatric species of Altaic osmans in the genus Oreoleuciscus was substantiated.     

Morphological Differentiation of Altai Osman Oreoleuciscus humilis (Cyprinidae) in the Tuin-Gol River,Lake Valley,Mongolia

Journal of Ichthyology - Variability of osteological characters of Altai osmans of the genus Oreoleuciscus in the Tuin River is studied. Two morphological forms are discerned on the basis of...     

Gastrointestinal parasites of critically endangered primates endemic to Tana River, Kenya: Tana River red colobus (Procolobus rufomitratus) and crested mangabey (Cercocebus galeritus)

We conducted fecal egg counts of gastrointestinal parasites of 2 critically endangered primates endemic to the forest of Tana River, Kenya. We aimed to use the fecal egg counts as proxies to quantify the prevalence of gastrointestinal parasites between the 2 primates. The Tana River red colobus (Procolobus rufomitratus) and crested mangabey (Cercocebus galeritus) are of similar body size, but their behavioral ecology is very different. We predicted that mangabeys would have a higher prevalence of parasites because they are mostly terrestrial omnivores, live in larger social groups, and therefore range widely. We detected 10 nematodes and 3 protozoans in mangabeys and 7 nematodes and 2 protozoans in colobus. We detected a higher number of different parasite species in individual mangabeys, and 4 of the 5 nematodes requiring intermediate hosts were found in mangabeys. The overall prevalence of parasites was higher for mangabeys, but this difference was not statistically significant. For colobus, we found a trend whereby the number of different parasite species in individual monkeys was higher in males and in lactating females. However, there was no difference in the prevalence of parasites between the sexes or between lactating and nonlactating females.     

The parasite fauna of the fish of the Shropshire Union Canal, Cheshire

A survey was made of the parasites of 603 roach Rutilus rutilus (L.), 15 bream Abramis brama (L.), 201 perch Perca fluviatilis L., 30 pike Esox lucius L. and four eels Anguilla anguilla (L.) caught in the Shropshire Union Canal at Backford, Cheshire from December 1964 to August 1966. Twenty-seven species of parasites were found, 17 in roach, seven in bream, ten in perch, ten in pike and two in the eel. Two species of Protozoa, seven species of Monogenea, five species of Digenea, six species of Cestoda, two species of Nematoda, one species of Acanthocephala, two species of Hirudinea, one species of Crustacea and mollusc glochidia were recorded. The following parasites are believed to be new records for the British Isles: Henneguya oviperda (Cohn, 1895), Dactylogyrus suecicus Nybelin, 1936, D. wunderi Bykhovskii, 1931, Asymphylodora kubanicum (Isaichikov, 1923), and Philometra rischta Skryabin, 1917.
One table shows the species of parasites found, together with data on the site of occurrence in the host, and the percentage and intensity of infection of the fish. A second table compares the occurrence of the parasites in four other localities in the British Isles, Loch Lomond Scotland, Llyn Tegid (Bala Lake), Merionethshire, Rostherne Mere, Cheshire and the River Lugg, Herefordshire. A further column gives the normal hosts in the U.S.S.R.
A limited comparison is made of the numerical occurrence of six species of parasites in the canal, Llyn Tegid and Druzno Lake, Poland. It is concluded that unless relatively large samples of fish of all length groups are collected on a regular basis throughout the year such comparisons will have little meaning.
The concept of the characterization of parasite faunas is briefly noted. It is suggested that the high degree of host specificity shown by many of the species of parasites is evidence in support of the concept.     

Metazoan parasite communities of wild Leporinus friderici (Characiformes: Anostomidae) from Amazon River system in Brazil

This study compared the structure of metazoan parasite communities in two populations of Leporinus friderici from two rivers of the Amazon River system in Brazil. Jainus leporini, Urocleidoides paradoxus, Urocleidoides sp., Tereancistrum parvus, Tereancistrum sp., Clinostomum marginatum, Procamallanus (Spirocamallanus) inopinatus, Contracaecum sp., Octospiniferoides incognita and Ergasilus sp. were found in both hosts. There were differences in species richness of parasites, Shannon index and the evenness between both host populations, because the parasite community showed a similarity of only 33%. Parasites of both host populations had an aggregated dispersion. Host size also contributes to the differences between the populations of hosts investigated, and the feeding habit contributes to the occurrence of endoparasites in L. friderici, an intermediate host for these parasites. The existence of variation in infracommunity and community of parasites for the same host species from different localities indicates the presence of an uneven distribution in terms of species and density of parasites, which are intermediate hosts, and some of them constitute food items for L. friderici in the localities surveyed.     

Fish parasite communities in tropical reservoirs along the Perak River, Malaysia

The parasite communities of fish in three reservoirs (Temengor, Kenering and Cenderuh) along the Perak River, as well as in the lower Perak, are compared. A total of 36 species, 51 species, 61 species and 58 species of metazoan parasites from six types of fishes common in all studied locations, were obtained in Temengor, Kenering, Cenderuh Reservoirs, and downstream Perak River, respectively. The various criteria (prevalence, mean intensity, diversity index, similarity index and evenness) of the parasite community were highest at the Cenderuh Reservoir, followed by the downstream river, Kenering, and Temengor Reservoirs. Monogeneans were the most common parasites in all species of fish examined from all study sites. Fish of the same species showed a high degree of similarity of its parasite fauna regardless of study site, but different hosts had a low similarity of their parasite fauna, even within the same study site. This revised version was published online in August 2006 with corrections to the Cover Date.     

Phylogenetic analysis of Altai osmans of the genus Oreoleuciscus (Pisces, Cyprinidae, Leuciscinae), based on the analysis of the cytochrome oxidase 1 gene (Co-1) sequence

Molecular genetic analysis of Altai osmans of the genus Oreoleuciscus from two different parts of the range was carried out. In this study, based on the mitochondrial Co-1 gene sequence, a total of 25 fish specimens belonging to four genera were examined: (1) O. humilis, 2 specimens; O. potanini, 13 specimens; (2) Pseudaspius leptocephalus, 1 specimen; (3) Tribolodon brandtii, T. hakonensis, and T. sachalinensis from the GenBank database, 8 speciens; and (4) Leuciscus waleckii, 1 specimen (used as an outgroup). The p-distances were very low both within and between the species: (1) 0.20 +/- 0.03%; (2) 0.40 +/- 0.12%; and (1-2) 0.80 +/- 0.04%. To visualize the relationships among all of the species examined, the neighbor joining (NJ), maximum parsimony (MP), Bayesian (BA), and maximum likelihood (ML) trees were constructed. The results obtained using these methods were very similar. It was demonstrated that species assignment of the individuals (barcoding) with the help Co-1 gene was effective, despite of very low divergence of the two osman taxa, which was comparable with typical intraspecific values in other animal groups. Taxonomic status of O. potanini and O. humilis requires further investigation with paying attention to low genetic distances between these species along with the lack of material from sympatric parts of the ranges.     

The occurrence of Eubothrium crassum (Cestoda: Pseudophyllidea) in salmon Salmo salar and trout S. trutta of the River Exe

The occurrence, size and maturity changes of Eubothrium crassum (Bloch) have been studied in smolts and adult Salmo salar L. and S. trutta L. of the River Exe and other Devon rivers. Adult parasites are found only in salmon and sea trout migrating up river to spawn, and range in size from small and immature to large and mature, though rarely gravid, worms. It is concluded that they are acquired and only become fully mature in the sea and gravid worms are lost on or before arrival in the rivers. During the upstream migration of salmon there is a selective loss of larger and more mature parasites and the survivors do not increase in length or mature, due to the intestine becoming a progressively more unfavourable habitat as the period of fasting continues. As few salmon return to the sea, most parasites in fresh-water die before breeding. In sea trout, which feed in fresh-water, parasites continue to grow and probably mature on return to the sea. It is suggested that parasites found in adult Atlantic and Pacific salmon in rivers are rarely, if ever, the same worms that are carried to sea by smolts but are of marine origin and are residues of a marine life cycle, and that two biological races of E. crassum exist, a marine and a fresh-water one.     

Fluctuations in densities of the invasive gill parasite Centrocestus formosanus (Trematoda: Heterophyidae) in the Comal River, Comal County, Texas, U.S.A

Centrocestus formosanus (Trematoda: Heterophyidae) is an invasive fish parasite in the Comal River, Texas, and is considered a threat to the federally endangered fountain darter, Etheostoma fonticola . Monitoring densities of C. formosanus cercariae is crucial to determining levels of infection pressure. We sampled 3 sites in the Comal River during 2 sampling periods, the first during 2006-2007, and again during 2009-2010. Two of the sites were located in the upstream reach of Landa Lake, sites HS and LA, and the third site was located downstream of Landa Lake in the old channel of the river. Cercariae densities were highest at the downstream most site (EA), followed by sites LA and HS, during both sampling periods, but a significant decline in cercariae density was observed between the first and second sampling periods. Several abiotic factors were monitored, including total stream discharge, wading discharge, temperature, and dissolved oxygen, but no river-wide trends were observed. Therefore, we speculate that these factors do not adequately explain the observed long-term decline in cercariae density. We propose that the decline is simply a reflection of a typical pattern followed by most invasive species as they gradually become integrated into the local community following an initial explosive growth in population size. Although cercariae densities may be abating, fountain darters in the Comal River are still threatened by the parasite, and conservation efforts must focus on reducing levels of infection pressure from the parasite whenever possible.     

Length–weight relationships of eight freshwater (Cypriniformes) fish species from Turkey

The length–weight relationships for eight freshwater fish species collected from Bey?ehir Lake, E?irdir Lake, Aksu River, Alara River, Göksu River and Menzelet Reservoir, were analysed. This paper represents the first LWR references for four of these species and also four of these species are endemic to Turkey.     

Seasonal dynamics of the population structure of Sphaerostomum globiporum (Trematoda: Opecoelidae) maritae in Ladoga Lake

Data on the seasonal dynamics of population structure is obtained for the first time for the Trematode species Sphaerostomum globiporum from roach Rutilus rutilus (L) in Ladoga Lake, which situates in the northern limit of the distribution range of this species. The parasites infest the host in October and leave it from the end of July to the beginning of August. The maximum of the magnitude of the Trematode population falls on spring, and the minimum is observed in summer. In August and September roach is free of the parasites. It is established that the period of maturing occupies 10 months for S. globiporum from roach in Ladoga Lake. The prereproductive period takes 5 months and comes to the end in February. The reproductive period occupies 5 months too. Although these two periods of the parasite's life cycle do not separated from each other clearly, an overlapping of two generations was not observed, unlike the case of more southern water bodies.     

Altered trophic pathway and parasitism in a native predator (Lepomis gibbosus) feeding on introduced prey (Dreissena polymorpha)

Populations of invasive species tend to have fewer parasites in their introduced ranges than in their native ranges and are also thought to have fewer parasites than native prey. This ‘release’ from parasites has unstudied implications for native predators feeding on exotic prey. In particular, shifts from native to exotic prey should reduce levels of trophically transmitted parasites. We tested this hypothesis in native populations of pumpkinseed sunfish (Lepomis gibbosus) in Lake Opinicon, where fish stomach contents were studied intensively in the 1970s, prior to the appearance of exotic zebra mussels (Dreissena polymorpha) in the mid-1990s. Zebra mussels were common in stomachs of present-day pumpkinseeds, and stable isotopes of carbon and nitrogen confirmed their importance in long-term diets. Because historical parasite data were not available in Lake Opinicon, we also surveyed stomach contents and parasites in pumpkinseed in both Lake Opinicon and an ecologically similar, neighboring lake where zebra mussels were absent. Stomach contents of pumpkinseed in the companion lake did not differ from those of pre-invasion fish from Lake Opinicon. The companion lake, therefore, served as a surrogate “pre-invasion” reference to assess effects of zebra mussel consumption on parasites in pumpkinseed. Trophically transmitted parasites were less species-rich and abundant in Lake Opinicon, where fish fed on zebra mussels, although factors other than zebra mussel consumption may contribute to these differences. Predation on zebra mussels has clearly contributed to a novel trophic coupling between littoral and pelagic food webs in Lake Opinicon.     

Demonstration of migration of juvenile cyprinid fish using parasite biomarkers

Migration of juvenile (0+) cyprinid fish from the Kiso River to experimental streams in the Aqua Restoration Research Center was demonstrated by the presence of parasites on fish. The experimental streams were located a minimum of 0.7 km from the main reach of the Kiso River, and they were connected via a tributary (Shinsakai River). The experimental streams were used as a spawning site and a nursery for juveniles, similar to the use of a temporary water body such as a paddy field. A digenean trematode (Centrocestus spp.) and the glochidia of unionid bivalves, both of which did not infect fish in the experimental streams or in the Shinsakai River, were used as marker parasites. Their presence indicated that the fish moved in the experimental streams from the Kiso River. For both fish species (Gnathopogon elongatus and Zacco platypus) assessed in this study, juveniles greater than 20–30 mm standard length could migrate from the Kiso River. This study showed that temporary waters are important as a nursery for juvenile fish, for whether or not a species spawns there. For the conservation of fish populations, it is important that temporary waters that are used as a nursery are connected with a permanent water area by a channel, through which not only adults, but also juvenile fish can migrate.     

Chironomids fauna (Diptera, Chironomidae) in some waterbodies and watercourses of Mongolia

An annotated list of chironomid species from some waterbodies and watercourses of Mongolia identified by an imaginal developmental stage is presented. The list includes 97 species of 39 genera and 5 subfamilies: Tanypodinae (6 species), Diamesinae (1), Prodiamesinae (2), Orthocladiinae (33), and Chironominae (55). Of all found chironomid imagos, 11 species have been earlier identified for the Mongolian fauna, the other 86 species have been registered for the first time. The largest number of species has been recorded in Lake Sangiyn-Dalai—28; in Lake Ugiy and River Ider—19 species. In the rest of the lakes, the number of recorded species varies from 18 to 10 species, and in rivers, from 13 to 2. Most of the species are boreal and widespread. The number of Paleoarctic species amounts to 44 and Holarctic species amounts to 49.     

The history of the formation of fish parasite fauna in lake Baikal

The fauna of fish parasites in Lake Baikal is represented by 5 faunistic complexes, namely the boreal plain, boreal submountain, arctic freshwater, Baikal, and Sino-Indian ones. The parasites of the boreal plain complex are dominant by the number of species (43 %). Hypotheses on the origin of the recent fish and parasite faunas of Lake Baikal were advanced on the base of the data on the parasite species composition and their distribution among hosts, as well as on the base of paleontological data. It is shown that invasion of new fish species and their parasites to Baikal led to the change of the composition of natural faunistic fish complexes and parasite systems. Invading fishes play the roles of intermediate and definitive hosts in parasite systems of Baikal, that led to the change of the initial structure of these systems.     

Determinants of the parasite community of clariid fishes from Lake Victoria, Tanzania

The factors that determine parasite assemblages among the clariid fishes of Lake Victoria, Tanzania were studied between August 2003 and February 2005. Six hundred and fifty-six fish belonging to seven species were necropsied and examined for parasites, from which 31 species of metazoan parasites were recorded. The community was dominated by the nematodes both in species and numbers. Most species were generalists with only two trematodes, Diplostomum mashonense and Tylodelphys species, being specialists of Clarias gariepinus. Ten species were considered core and predictable. Parasite species richness, number of individuals per host and Shannon-Wiener diversity indices were generally high. At the compound community level, a mean number of 7.8 parasites were shared among different species of fish and the maximum number of parasites species per fish at the infracommunity level was seven. Levels of similarity in parasite species richness at the component community level ranged from 29.6 to 61.5%. The study concludes that parasite communities in clariid fishes of Lake Victoria are structured by ecological factors. At the infracommunity level, host size, diet and vagility promoted a richer parasite community. At the compound level, two factors were crucial, namely the intermixing of the waters in the lake and the predominant and mobile C. gariepinus.