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.     

Anthropogenic impact on fish parasite fauna in lakes

Anthropogenic influence on the fish parasite fauna in lakes is studied. Three types of the influence are considered, namely pollution by industrial effluent, anthropogenic eutrophication, and development of aquaculture. Their effects on the fish parasite fauna were found to be different.     

The parasite fauna of the big and little Baikal oil fishes

The parasite fauna of two endemic fish species of the genus Comephorus (Cottoidei: Comephoridae) includes 11 species. Six species were found in Comephorus baicalensis and 9--in C. dybowskii. Two species only are endemic for Baikal: Myxidium perniciosum and Gyrodactylus comephori. Other 9 species are distributed throughout Palaearctic region. Ecology of parasites and their hosts is briefly discussed.     

Patterns of host specificity among the helminth parasite fauna of freshwater siluriforms: testing the biogeographical core parasite fauna hypothesis

Host specificity plays an essential role in shaping the evolutionary history of host-parasite associations. In this study, an index of host specificity recently proposed was used to test, quantitatively, the hypothesis that some groups of parasites are characteristics of some host fish families along their distribution range. A database with all published records on the helminth parasites of freshwater siluriforms of Mexico was used. The host specificity index was used considering its advantage to measure the taxonomic heterogeneity of the host assemblages and its appropriateness for unequal sampling data. The helminth parasite fauna of freshwater siluriforms in Mexico seems to be specific for different host taxonomic categories. However, a relatively high number of species (47% of the total helminth fauna) is specific to their respective host family. This result provides further corroboration for the biogeographic hypothesis of the core helminth fauna proposed previously. The statistical values for host specificity obtained herein seem to be independent of host range. However, the accurate taxonomic identification of the parasites is fundamental for the evaluation of host specificity and the accurate evolutionary interpretation of this phenomenon.     

Some observations on the distribution and life history of Caenis robusta Eaton (Ephemeroptera) in Cheshire and North Shropshire,England

Caenis robusta Etn. was found in only 8 of 107 water bodies sampled. All the habitats from which it was recorded contained plant debris; the waters were still or slow-flowing and had conductivities ranging from 120–687 µmhos cm^–1 at 25°C.In North Shropshire, England, C. robusta had one generation per year. Newly hatched nymphs were abundant in August and growth occurred rapidly until September. No growth took place from October until March but was again rapid from April until June. Emergence took place at dusk in late June and July.     

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.     

The phytoplankton of Crose Mere,Shropshire

The succession of phytoplankton in a small lowland eutrophic lake (mere) over six years is described, with particular reference to the annual occurrence of the dominant forms. Integrated data reveal a seasonal pattern in both the quality and quantity of populations, which typifies the periodicity of the meres in the region but differs in detail from those of temperate eutrophic lakes elsewhere.     

台湾海峡鱼类组成及其生态区系

本文依据台湾海峡鱼类物种的相关历史调查资料和文献, 分析了台湾海峡鱼类物种组成及其生态类型和区系特征, 探讨全球变化背景下台湾海峡鱼类物种组成变化。结果显示, 台湾海峡共有鱼类1,697种, 分隶40目206科740属, 其中, 目级分类阶元种类数最多的为鲈形目, 科级分类阶元种类数最多的为鰕虎科; 从适温性上看, 暖水性鱼类最多, 有1,560种, 其次为暖温性鱼类(128种)和冷温性鱼类(9种); 栖息地生态类型则以大陆架砂泥质底层鱼类和岩礁性鱼类种类数最多, 各有596种, 其后依次是大陆架近底层鱼类(249种)、大陆架中上层鱼类(158种)和大洋性鱼类(98种), 洄游性鱼类181种, 经济性鱼类735种; 海区间鱼类种类数对比显示, 台湾海峡鱼类与南海鱼类共有种最多, 共有种比例高达91.9%, 其次为东海(69.3%)和黄海(19.4%), 多为印度—西太平洋海区分布种, 仅288种广泛分布于中国各海区。由此, 台湾海峡鱼类区系特征兼有热带和亚热带海区鱼类区系特点, 属于印度—西太平洋暖水区系中—日亚区和印度—马来亚区的过渡海区, 其分界区域在台湾浅滩东部外缘至澎湖列岛偏北海域。     

The fish fauna changes and the place of clupeids in Lake Kainji,Nigeria

The fish fauna changes and the place of the clupeids was examined. It was found that the conditions in the lake since impoundment have favoured the growth and development of these little sardines. The studies undertaken prior to impoundment and their continuation right from the time of the closure of Kainji Dam in August 1968 has made it possible for these changes to be followed sequentially.     

The fish fauna of mountain streams in the Guanshan National Nature Reserve, Jiangxi, China

Guanshan National Nature Reserve (GNNR) is located in the middle reach of the Jiuling Mountain Range in the southern China and the first national nature reserve within Jiangxi Province. The fish fauna of mountain streams in the GNNR was investigated from September 2006 to August 2007. A total of 379 fish were collected and classified into two families and seven species. Acrossocheilus parallens [relative abundance (RA) 44.3%] was the most abundant fish species. Subdominant species were Onychostoma barbata (RA, 20.3%), Zacco platypus (RA, 14.2%) and Opsariichthys bidens (RA, 12.4%).A greater number of species (7 vs. 2) and individuals (295 vs. 84) were collected from the West Stream compared to the East Stream. Among the seven fish species collected in the GNNR, Acrossocheilus parallens, Onychostoma barbata and Vanmanenia stenosoma are endemic to the Chinese mountain streams. This study suggests that mountain streams in the nation reserves including GNNR are very important for freshwater fish diversity and conservation in Jiangxi Province.     

The parasite fauna of cod (Gadus morhua L.) in Balsfjord,North Norway

Summary Samples of cod from Balsfjord, a subarctic fjord in North Norway, were collected and the fauna of macro-parasites was classified zoogeographically. The results revealed an impoverished and to a large extent boreal parasite fauna compared with that of cod from the Barents Sea. Because of the last glaciation Balsfjord is a relatively young ecosystem, and the silled entrance surrounded by an archipelago also makes the fjord a rather isolated system. This together with its small size may be important factors in explaining the character of its parasite fauna. The colonization by boreal parasites of both the Barents Sea and Balsfjord probably reflects the direction of the main currents.     

Post-impoundment changes in the fish fauna of Lake Itezhi-tezhi, Zambia

The fish fauna of the newly inundated Lake Itezhi-tezhi, Zambia was observed between 1980 and 1985. Marked changes in the community structure were identified. The most obvious were a decline in species diversity and a shift in species composition from acommunity with a preponderance of Alesles lateralis (Boulenger) (Characidae), to one dominated by cichlids. These changes were primarily due to members of the families Cyprinidae, Mormyridae and Schilbeidae being unable to adapt to the new environmental conditions, such as spawning and feeding grounds, and their inability to cope with fluctuating water levels in the lake. It was suggested that a sound fishery data collection system be implemented to provide reliable information on which to base management policy.     

The structure and organization of an eelgrass fish fauna

Summary Ten species of fish made up more than 95 percent of the standing crop of the total fish assemblage of a shallow-water eelgrass meadow in southeastern Australia. The relative abundance of each species remained fairly constant from year to year during a four and a half year period. Four species were permanent residents, three moved over the meadow at high tide, and the juveniles of three species changed residence status as they grew. Most species exhibited distinct diel patterns of activity, four species were diurnal and five were nocturnal. Species foraged in different microhabitats and dietary overlap was very low amongst all but two species which had overlapping habitat, prey and prey size preferences, but had different diel activity periods. Data on production by prey and consumption of prey by these two fish species indicated that competition for food was probably responsible for the temporal separation of feeding niches. Predation by birds and fish appeared to be the major influence on the diel activity period of one fish species. The maintenance of the patterns of resource allocation among the remaining species is discussed and the organization of different seagrass fish faunas is compared.This is publication number 265 in the Ministry for Conservation, Victoria publication series. — Present address: Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada     

The status of the Irish freshwater fish fauna: a review

The status of the Irish freshwater fish fauna is reviewed. Of the 25 Irish species, 11 are introduced and five are considered as endangered or vulnerable. Agriculture through eutrophication, farm wastes and overgrazing, and afforestation and introductions are the main threats to the native fauna.     

Characteristics of the introduced fish fauna of Israel

Fishes have been introduced worldwide with deleterious effects on various native ecosystems. To gain insight into this phenomenon in Israel, we studied the introduced ichthyofauna. There are 27 species of introduced fishes in the freshwater habitats of Israel, a large number for a nation this size. Ten of these species reproduce in the wild. Most of these fishes were introduced for aquaculture; some are constantly restocked. The proportion of restocked versus established species in Israel is high compared to other regions. New fish introductions continue in recent decades, unlike the global trend. In Israel these species are found in the Jordan Basin, Lake Kinneret (Sea of Galilee), and the coastal plain rivers. A few species are widespread, and most are found in Lake Kinneret. Harmful effects of introduced fishes have been suspected and in several cases demonstrated. We encourage further caution when new introductions are contemplated; in some regions eradication should be attempted.     

The dominant fish fauna in the North Sea and its determination

The 224 species of fish reported from the North Sea are regarded as being composed of elements of three faunas—Boreal, Lusitanian and Atlantic, and they can be grouped accordingly on both a number of species and a biomass basis. The estimation of biomass of more than 10 important species is based on stock estimates obtained from population data. For 65 non-standard species the estimate is based on a comparison of catch rates for 'standard'and non-standard species from groundfish survey data. This involves assumption about the relative catchability of different sets of species. For the other species the biomass are computed in different ways. An analysis of the dominant fish fauna in the North Sea is attempted. The fish fauna in the area is analysed in two ways: by the conventional total number of species from each zoogeographic area, and by the biomass of the representatives of each fauna. It is concluded that for establishing the dominant faunal element of fish, biomass is a better index than is the number of species. The dominant faunal element of fish in the North Sea is Boreal.     

The Tortonian fish fauna of Gavdos Island (Greece)

Although the occurrence of fossil fishes is known since more than one century in the Neogene of Gavdos Island (Greece), its composition remained hitherto unknown. The present study demonstrates that, in the Tortonian of Gavdos, the most abundant species is Bregmaceros albyi (Sauvage), which constitutes two thirds of the collected material. This fish fauna is indicative of an environment of moderate depth, probably corresponding to the external edge of the neritic zone, or possibly to the upper part of the continental slope. To cite this article: J. Gaudant et al., C. R. Palevol 4 (2005).     

The fish fauna of the Jordan reservoir, one of the oldest man-made lakes in central Europe

The Jordan reservoir, Czechoslovakia, was constructed in 1492 and the last full drainage and fish removal was in 1830. In this 'mature' fish community of 20 species (plus three hybrids), the roach, Rutilus rutilus (L.) (1446 fish ha^–1) and beam, Abramis brama (L.) (1074 fish ha^–1) dominated the fish stock (total of all species = 3628 fish ha^–1). Predatory species made a small contribution to the total (maximum 7.7%, obligatory predators 2%). The contribution (12%) by perch, Perca fluviatilis L., was also low, and its numbers in successive age-groups showed a steady decrease. The high variability and time-synchronization in the year-class strengths of the principal cyprinid species may indicate unstable environmental conditions or intra-community cycles. The growth rates of non-predatory species were low. There was a high fishing rate on predatory species but there was little impact by fishery management on the whole 'mature' community. Intensive eutrophication from both communal waters and agriculture probably caused the high biomass level (all species) and the low abundance of zander, Stizostedion lucioperca (L.).     

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.