The Effect of Fish Introductions on the Diatom and Cladoceran Communities of Lake Opeongo,Ontario, Canada

Fish introductions are one of the most widespread anthropogenic perturbations to aquatic ecosystems. Paradoxically, the effects of these introductions on aquatic ecosystems are typically poorly documented. This project studied the effect of fish introductions on Lake Opeongo, an oligotrophic lake in Algonquin Provincial Park, Ontario, Canada (45° 42′ N, 78° 22′ W), using the remains of algae (diatoms) and zooplankton (cladocerans) preserved in the sediments. It was hypothesized that the introduction of cisco or lake herring (Coregonus artedii Lesueur) in 1948, which filled the underutilized pelagic forage fish niche, should have altered nutrient availability for phytoplankton. Prior to cisco introduction, the diatom community of Lake Opeongo reflected a relatively stable oligotrophic state established before European settlement, and consisted of the Cyclotella stelligera complex with subdominants Tabellaria flocculosa IIIp and the Aulacoseira distans complex. No marked changes occurred until ca. 1962 when the diatom community shifted to an assemblage with increased total phosphorus preferences, consisting of Asterionella formosa and lesser amounts of Cyclotella bodanica var lemanica, the C. stelligera complex, Fragilaria crotonensis and T. flocculosa IIIp. The dominant cladoceran Bosmina longirostris increased significantly in relative abundance since the introduction of cisco. The most likely cause of this shift was increased nutrient recycling and/or trophic level changes caused by human manipulation of the fish community of the lake.     

Habitat coupling in a large lake system: delivery of an energy subsidy by an offshore planktivore to the nearshore zone of Lake Superior

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How important are trophic state,macrophyte and fish population effects on cladoceran community? A study in Lake Erhai

Environmental controls on cladoceran community structure in lake ecosystems are complex and may involve many environmental parameters including trophic state and fish populations. In Lake Erhai, a plateau lake located in southwest China, it was hypothesized that a combination of lake eutrophication and planktivorous fish introduction would increase the abundance of cladoceran, while also decreasing cladoceran size. To test this hypothesis, we examined temporal changes in cladoceran microfossils in the sediments of Lake Erhai over the past century. The influence of changing macrophyte coverage within the littoral region of the lake was also considered. Results demonstrated that cladoceran abundance (measured as flux of cladoceran fossils in the sediments) increased markedly accompanying eutrophication of the lake. In addition, there was a shift in the dominant cladoceran species from those species that prefer oligotrophic conditions to those that prefer mesotrophic and eutrophic conditions. A reduction in the ephippium length of Daphnia spp. was observed and attributed to the introduction of the planktivorous fish Neosalanx taihuensis. Our findings indicated that eutrophication and fish introduction were the main controls affecting cladoceran community structure during the recent decades, and predation by planktivorous fish had an important impact on Daphnia body size.     

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.     

<Emphasis Type="Italic">Coregonus peled</Emphasis> (Gmelin) transplanted into Ulaagchny Khar lake (western mongolia) showed no evidence of hybridization with other introduced <Emphasis Type="Italic">Coregonus</Emphasis> species

Coregonus peled (Gmelin) (Teleostei: Salmoniformes: Coregonidae), which is considered an important object of coldwater aquaculture, had been successfully introduced into an enclosed Western Mongolian lake Ulaagchny Khar in the early 1980s. At the same time larvae of two other Coregonus species—Baikal omul C. migratorius (Georgi) and least cisco C. sardinella Valenciennes—had also been released into the lake. Baikal omul was then reported as a naturalized species. This might have caused interspecific hybridization and gene introgression. Identification of coregonids by morphology can be problematic, so to determine which species was dominant in the lake (we presumed it was peled) and if its gene pool was affected by other introduced Coregonus species we sampled 40 individuals and analyzed them by sequencing a fragment of mtDNA cyt b and by allozyme electrophoresis. The analysis showed that all the fish belonged to C. peled with no evidence of admixture from other coregonid species. Taking into account mass release of both species in 1980s, it is evident that naturalization of peled in the lake was much more successful than that of Baikal omul.     

Genetic differentiation of coregonid fishes in pechora river

A population–genetic study of five coregonid fish species has been carried out using 30 enzyme loci. The species under study included whitefish, a natural hybrid of vendace and least cisco, inconnu, peled, and Arctic cisco. The investigation revealed a low intraspecific genetic differentiation of the abovementioned species from Lower Pechora River and Usa River, which is the main tributary in the Pechora River basin, where coregonid fishes migrate to spawn. Presumably, whitefish, vendace, and inconnu inhabiting the main channels of Lower Pechora and Usa rivers are represented here by introgressive populations of species formed by a mix of discrete evolutionary lineages originating from geographically separated Late Quaternary refugia. Some lineages of whitefish, vendace, and inconnu from the West Siberian periglacial lake came to Eastern Europe together with the last migration wave of Siberian species to the west, including peled, broad whitefish, and Arctic cisco, during the Middle Weichselian glaciation (60000–50000 years ago), while in the Eastern European Periglacial refugium (Lake Komi), local lineages of these species had survived. The periglacial Lake Komi has probably been located on the Pechora Plain since early Weichselian glaciation (90000–80000 years ago), and the studied whitefish specimens from Upper Pechora River are probably the purest descendants of the periglacial race of whitefish from Lake Komi. This assumption is supported by the data on the high level of genetic differentiation between the whitefish of Upper Pechora and Lower Pechora (D _N = 0.005), as well as by the pattern of allele distribution in some polymorphic loci. In our opinion, the ecologic and genetic differentiation of vendace in the Pechora River basin is also connected with the interaction between two evolutionary lineages that originated from independent periglacial refugia.     

Modification of the diel vertical migration of Bythotrephes longimanus by the cold-water planktivore, Coregonus artedi

1. The weak diel vertical migration observed in the large cladoceran Bythotrephes longimanus seems contradictory to the predator‐avoidance hypothesis that predicts large zooplankton should have long migration amplitudes. However, cold‐water planktivores, especially Coregonus spp., are a main source of mortality for Bythotrephes and hence a deeper migration would result in a greater overlap with these hypolimnetic planktivores. We hypothesized that Coregonus artedi (cisco) modifies the normal vertical migration pattern of Bythotrephes, such that the latter stays higher in the water column during the day and thus migrates less extremely at night. 2. The vertical distribution of Bythotrephes during the day was determined from single visits to six lakes in Ontario, Canada, all of which contain warm‐water, epilimnetic planktivores but differing in whether they contain cisco. One lake of each fish type was sampled day and night every 2–3 weeks over the ice‐free season to examine daytime depths and migration amplitude. 3. The vertical migration of Bythotrephes differed in the presence and absence of cisco. In the lakes with cisco, there were significantly fewer Bythotrephes in the hypolimnion and they were higher in the water column during the day. Migration amplitude was smaller in the cisco than in the non‐cisco lake. These observations were not attributable to differences in physical factors, and, although not conclusively attributable to cisco, are consistent with an effect of cisco. 4. We suggest that diurnal depth selection by Bythotrephes in lakes containing cisco is a trade‐off between the risk of predation by warm‐ versus cold‐water predators, balanced by the benefits of increased temperature and feeding rates near the surface. Even in lakes without cisco, however, the vertical migration of Bythotrephes was less than expected, suggesting that diurnal depth selection is a balance between the risk from warm‐water planktivores and access to sufficient light to feed effectively.     

Invasive Crayfish Threaten the Development of Submerged Macrophytes in Lake Restoration

Submerged macrophytes enhance water transparency and aquatic biodiversity in shallow water ecosystems. Therefore, the return of submerged macrophytes is the target of many lake restoration projects. However, at present, north-western European aquatic ecosystems are increasingly invaded by omnivorous exotic crayfish. We hypothesize that invasive crayfish pose a novel constraint on the regeneration of submerged macrophytes in restored lakes and may jeopardize restoration efforts. We experimentally investigated whether the invasive crayfish (Procambarus clarkii Girard) affects submerged macrophyte development in a Dutch peat lake where these crayfish are expanding rapidly. Seemingly favourable abiotic conditions for macrophyte growth existed in two 0.5 ha lake enclosures, which provided shelter and reduced turbidity, and in one lake enclosure iron was added to reduce internal nutrient loading, but macrophytes did not emerge. We transplanted three submerged macrophyte species in a full factorial exclosure experiment, where we separated the effect of crayfish from large vertebrates using different mesh sizes combined with a caging treatment stocked with crayfish only. The three transplanted macrophytes grew rapidly when protected from grazing in both lake enclosures, demonstrating that abiotic conditions for growth were suitable. Crayfish strongly reduced biomass and survival of all three macrophyte species while waterfowl and fish had no additive effects. Gut contents showed that crayfish were mostly carnivorous, but also consumed macrophytes. We show that P. clarkii strongly inhibit macrophyte development once favourable abiotic conditions for macrophyte growth are restored. Therefore, expansion of invasive crayfish poses a novel threat to the restoration of shallow water bodies in north-western Europe. Prevention of introduction and spread of crayfish is urgent, as management of invasive crayfish populations is very difficult.     

First attempt to apply whole-lake food-web manipulation on a large scale in The Netherlands

Lake Breukeleveen (180 ha, mean depth 1.45 m), a compartment of the eutrophic Loosdrecht lakes system, was selected to study the effects of whole-lake foodweb manipulation on a large scale. In Lake Loosdrecht (dominated by filamentous cyanobacteria), due to water management measures taken from 1970–1984 (sewerage systems, dephosphorization) the external P load has been reduced from 1.2 g m⁻² y⁻¹ to 0.35 g m⁻² y⁻¹. The water transparency (Secchi-depthca. 30 cm), however, has not improved. The aim of the food-web manipulation in Lake Breukeleveen was not only to improve the light climate of the lake, but also to study if the successfull effects observed in small lakes (a few ha) can be upscaled. In March 1989 the standing crop of planktivorous and bentivorous fish populations was reduced by intensive fishery, fromca. 150 kg ha⁻¹ toca. 57 kg ha⁻¹. The lake was made unaccessible to fish migrating from the other lakes and it was stocked with large-sized daphnids and 0⁺ pike. However, water transparency did not increase in the following summer and autumn 1989, which is in contrast with great improvement in the light conditions previously observed in smaller lakes. The main explanations for the negative outcome in Lake Breukeleveen are: 1) the rapid increase of the planktivorous fish biomass and carnivorous cladocerans, predating on the zooplankton community; 2) suppression of the large daphnids by the high concentrations of filamentous cyanobacteria; 3) high turbidity of the lake due to resuspension of bottom material induced by wind, unlike in smaller lakes, and thus inability of submerged macrophytes to develop and to stabilize the ecosystem.     

Prey preferences in captivity of the freshwater crab Potamonautes lirrangensis from Lake Malawi with special emphasis on molluscivory

Freshwater crabs play an important role for the diversification of shell morphologies in freshwater gastropods. For example, the radiation of the freshwater crab genus Platythelphusa in Lake Tanganyika is thought to have driven shell diversification of the lake’s snail fauna, promoting the evolution of thalassoid shells. No comparable thalassoid snails are known from Lake Malawi. Accordingly, it was hypothesized that the lake’s only freshwater crab, Potamonautes lirrangensis, is not a snail predator. We tested this hypothesis using feeding experiments with specimens caught in the southern part of Lake Malawi. Individual crabs were held in experimental containers offshore and were presented with various food items overnight, after which ingestion frequency was recorded. Potamonautes lirrangensis can be characterized as a scavenger that is opportunistically carnivorous. A preference for fish and snail flesh could be observed, indicating a bias toward carnivory. We observed occasional cracking of the shell in different snail species, with frequent ingestion of artificially crushed specimens, suggesting that crabs do attempt to feed on snails. However, the investigated Lake Malawi gastropods appear to be partly protected against crab predation through thick-walled and low-spired shells (especially Lanistes and Bellamya), obviating the evolution of thalassoid shells carrying rims, ridges, or spines.     

Genetic comparisons of New and Old World coregonid fishes*

The genetic relationships among New and Old World coregonid fishes were studied by electrophoresis. The genetic composition of 60 populations, representing perhaps nine commonly recognized species of Coregonus and Stenodus from Europe and North America was determined for 37 genetic loci. Six distinct genetic groups were evident. The first contained only populations of the inconnu, Stenodus leucichthys (Güldenstadt). The Nei genetic distance between Stenodus and Coregonus was 0.305, a relatively small value as compared to other salmonid inter-generic comparisons. The second genetic grouping contained the Arctic cisco, C. autumnalis (Pallas), the N. American lake cisco, C. artedii Lesueur, and the Irish pollan, C. autumnalis pollan Thompson. These three taxa appear to be conspecific on the basis of genetic distances. The third genetic grouping contained the European whitefish, C. lavaretus (L.), and the N. American lake whitefish, C. clupeaformis (Mitchill). European and lake whitefish may be conspecific. Lake whitefish from northwestern N. America were more closely related to European whitefish (genetic distance 0.038) than to lake whitefish from central N. America (genetic distance 0.098). The fourth group contained the broad whitefish, C. nasus (Pallas), which is perhaps more closely related to the European/lake whitefish groups than other coregonids. The fifth genetic grouping contained only the Asian endemic, C. peled (Gmelin), and the sixth contained the least cisco, C. sardinella Valenciennes, and vendace, C. albula (L.), which also appear to be conspecific. The widespread genetic groupings obtained for ciscoes indicate that they do not constitute a single closely related group within the genus Coregonus.     

The Radiation of Hydrobioid Gastropods (Caenogastropoda, Rissooidea) in Ancient Lake Poso, Sulawesi

A survey of the fauna of hydrobioid gastropods living in ancient Lake Poso in Sulawesi revealed a total of 16 species, 14 of them new, belonging to two genera, Sulawesidrobia and Keindahan gen. nov. Most species occurred on hard substrates, water plants or rootlets of trees. Since only the upper 0.5 m of the lake have been sampled, many more species probably remain to be discovered. Already, Lake Posoȁ9s fauna ranks among the four most diverse hydrobioid lake faunas worldwide. The Sulawesi lakes including Lake Poso and the Malili Lakes are the only lakes where sizeable radiations of hydrobioid and cerithioid gastropods coexist. Outside Lake Poso, hydrobioid gastropods have not been investigated so far apart from a single species reported from Lake Lindoe similar to or identical with S. bonnei [Abbott, 1945. Occasional Papers on Mollusks 1: 1–4], which has its type locality in Lake Poso and may in fact be a complex of species. Therefore endemicity in Lake Poso cannot be estimated nor is it possible to say, whether the radiation is of lacustrine origin. The introduction of alien fish has had a severe impact on the native fish fauna. The impact on the invertebrate fauna is not known but chances are that this survey based on collections from 1991 no longer reflects the original assemblage in the lake.     

Food and food selection of cisco (Coregonus albula L.) in a dysoligotrophic lake

With minor exceptions, cisco (C. albula) in Lake Suomunjärvi fed on cladocerans and copepods. The food habits were different among two size classes of fish. The composition of cisco diet changed at different depths and times of the day, but the distribution of zooplankton was usually very similar in each period irrespective of the depth or diel period. Daphnia, Bosmina, Cyclops scutifer and Heterocope appendiculata were the main diet of cisco. Calculations of fish electivity indices showed that cisco selected usually large species of cladocerans and copepods and a small cladoceran, Bosmina coregoni. Body-size selection was clear for Daphnia and Bosmina.     

On the origin of Solovetskaya vendace <Emphasis Type="Italic">Coregonus albula</Emphasis> and of the syamozero smelt <Emphasis Type="Italic">Osmerus eperlanus</Emphasis>

The genetic analysis is made on the population of the European smelt Osmerus eperlanus occasionally introduced to Lake Syamozero (Karelia) and of the vendace Coregous albula supposedly acclimatized in Solovetskie Islands as a result of fish cultural activities of the Solovetskii Monastery. They are compared with several natural populations—possible donors for both introductions. Genetic variation in a sample of smelt was estimated by means of restrictase analysis of mtDNA (fragment ND1/ND2) in samples of vendace—by means of allozyme analysis of six isoenzyme systems. The probable population for the Syamozero smelt is the population of Onega Lake in spite of the previously noted greater morphological similarity of colonizers with the smelt of Ladoga Lake. A high level of genetic variation in the Syamozero smelt in comparison with native populations indicates that, beside the introduction from Onega Lake, there were repeated introductions from neighboring water bodies. The genetic analysis of the Solovetskaya vendace does not prove that the vendace appeared on islands due to acclimatization. Frequencies of alleles of allozyme loci in the Solovetskaya population significantly differ from frequencies in continental populations. Still, it is compared with some populations of the Arkhangelsk oblast. Estimations of genetic diversity of the Solovetskaya vendace turned out to be comparable with those in native populations.     

Metal Levels in the Liver,Muscle, Gill,Intestine, and Gonad of Lake Van Fish (Chalcalburnus tarichi) with Abnormal Gonad

Recently, an increasing number of studies have shown that Lake Van—the biggest soda lake in the world—is polluted due to an increasing population. Studies have shown abnormalities in the Lake Van fish (Chalcalburnus tarichi), the sole fish species that inhabits the lake. Unlike the vitellogenic and mature oocytes in normal gonads, abnormal gonads show large amounts of connective tissue and young oocytes. In this study, metal levels (nickel [Ni], copper [Cu], cobalt [Co], iron [Fe], zinc [Zn], cadmium [Cd], lead [Pb], and manganese [Mn]) in the muscle, liver, gill, intestine, and gonad of Lake Van fish with normal and abnormal gonads were assessed. Further, the metal contents in the wastewater from the wastewater treatment facility situated near Lake Van in Van City were assessed. All the metal levels, except that of Zn, were high in the Lake Van environment (P?<?0.05). The highest metal content in the tissues was for Fe, while the lowest level was for Co. The Pb level was found to be very high in both fish groups. Cd was not found in the tissues of both fish groups. The levels of Fe, Cu, Pb, and Mn were not significant in the tissues of both normal and abnormal fish groups. Zn level was significantly high in the livers and gonads of fish with abnormal gonads, and Co level was significantly high only in the livers (P?<?0.05). Consequently, high levels of Zn in the liver and gonads and high levels of Co in the liver may be factors causing the abnormal gonads in the Lake Van fish.     

长江中游典型草型湖泊与藻型湖泊鲫种群结构和生长比较(英文)

浅水湖泊牛山湖和月湖均位于长江中游武汉市境内,前者水质清澈、沉水植物茂盛,属典型的草型湖泊;后者长期受生活污水和工业废水排放的影响,水质恶劣、沉水植物稀少,属典型的藻型湖泊。文章选择这两个湖泊的共同优势鱼类——鲫(Carassius auratus)作为研究对象,通过比较两类不同湖泊环境条件下鲫种群结构和生长上的差异,评估人类活动引起的水环境改变对鱼类种群生存状况的影响。2006年春季(3—5月),于牛山湖和月湖各采集鲫种群样本713尾和641尾,研究结果表明:(1)牛山湖和月湖鲫种群的全长频数分布经kolmogorov-Smirnov检验均符合正态分布,但前者的分布范围(63—271 mm)大于后者(72—191 mm),前者的全长峰值(190 mm)亦大于后者(110 mm);(2)牛山湖鲫种群的年龄组成(6个年龄组)较月湖(仅3个年龄组)完整,但月湖各龄鲫的全长均显著大于牛山湖(P<0.05);(3)两个湖泊性成熟鲫的雌、雄鱼比均随全长的增长而增加,即小个体性成熟鲫以雄鱼为主,大个体性成熟鲫以雌鱼为主,该现象在月湖更为明显;(4)牛山湖和月湖鲫全长–体重回归关系(W=a Lb)分别为W=0.00001 L3.060(R2=0.989)和W=0.000006 L3.246(R2=0.971),协方差分析表明两个湖泊鲫种群的b值差异极显著(P<0.01);另一方面,月湖鲫种群各全长组雌、雄鱼的肥满度均显著大于牛山湖(P<0.05)。作者认为影响牛山湖和月湖鲫生长和种群结构的主要因素是两个湖泊饵料组成和捕捞压力等方面的差异。     

Food resource effects on diel movements and body size of cisco in north-temperate lakes

The movement patterns and body size of fishes are influenced by a host of physical and biological conditions, including temperature and oxygen, prey densities and foraging potential, growth optimization, and predation risk. Our objectives were to (1) investigate variability in vertical movement patterns of cisco (Coregonus artedi) in a variety of inland lakes using hydroacoustics, (2) explore the causal mechanisms influencing movements through the use of temperature/oxygen, foraging, growth, and predation risk models, and (3) examine factors that may contribute to variations in cisco body size by considering all available information. Our results show that cisco vertical movements vary substantially, with different populations performing normal diel vertical migrations (DVM), no DVM, and reverse DVM in lakes throughout Minnesota and northern Wisconsin, USA. Cisco populations with the smallest body size were found in lakes with lower zooplankton densities. These smaller fish showed movements to areas of highest foraging or growth potential during the day and night, despite moving out of preferred temperature and oxygen conditions and into areas of highest predation risk. In lakes with higher zooplankton densities, cisco grew larger and had movements more consistent with behavioral thermoregulation and predator avoidance, while remaining in areas with less than maximum foraging and growth potential. Furthermore, the composition of potential prey items present in each lake was also important. Cisco that performed reverse DVM consumed mostly copepods and cladocerans, while cisco that exhibited normal DVM or no migration consumed proportionally more macro-zooplankton species. Overall, our results show previously undocumented variation in migration patterns of a fish species, the mechanisms underlying those movements, and the potential impact on their growth potential.     

Phenotypic plasticity of a transplanted population of dwarf cisco,Coregonus artedii

Synopsis A population of dwarf cisco in Minnesota was studied in native and transplant environments. Life history characters were recorded and the stability of meristics and morphometrics of the population over a two year period in three different environments was assessed with univariate and multivariate statistics. Transplanted cisco lived longer and grew larger than they did in their native lake, yet retained distinctive pigmentation patterns and an unusually early spawning season. Meristic characters of dwarf fish remained within ranges reported forCoregonus artedii during the lifetimes of individuals in their new environments, but morphometric measures underwent significant size- and shape-related changes. Incubation and rearing studies show egg incubation time and behavior of larvae were identical of those of non-dwarf cisco. Comparisons with non-dwarf cisco populations illustrate the ecophenotypic plasticity of adult fish of this population of North American cisco. Present address: Fish Division, Museum of Zoology, University of Michigan, Ann Arbor, MI 48109, U.S.A.     

Repeated Lake-Stream Divergence in Stickleback Life History within a Central European Lake Basin

Life history divergence between populations inhabiting ecologically distinct habitats might be a potent source of reproductive isolation, but has received little attention in the context of speciation. We here test for life history divergence between threespine stickleback inhabiting Lake Constance (Central Europe) and multiple tributary streams. Otolith analysis shows that lake fish generally reproduce at two years of age, while their conspecifics in all streams have shifted to a primarily annual life cycle. This divergence is paralleled by a striking and consistent reduction in body size and fecundity in stream fish relative to lake fish. Stomach content analysis suggests that life history divergence might reflect a genetic or plastic response to pelagic versus benthic foraging modes in the lake and the streams. Microsatellite and mitochondrial markers further reveal that life history shifts in the different streams have occurred independently following the colonization by Lake Constance stickleback, and indicate the presence of strong barriers to gene flow across at least some of the lake-stream habitat transitions. Given that body size is known to strongly influence stickleback mating behavior, these barriers might well be related to life history divergence.     

Case study of microsatellite polymorphism of European perch in selected commercially important lakes of Latvia

Polymorphism of selected microsatellite markers was described for European perch populations of inland Lake Kala and costal Lake Babites in Latvia. The data consisted of ten microsatellite loci analysed for 90 individuals from the Lake Babites (n?=?45) and the Lake Kala (n?=?45). Both lakes differ in water area, connection with the Gulf of Riga (Baltic Sea), lake type, and fish species. In the Lake Kala population, the average number of alleles per locus varied from 4 to 15 and in the population of Lake Babites from 4 to 12. Low but significant genetic differentiation was detected between populations (F_ST?=?0.046). Observed and expected heterozygosity in both lakes was similar (Kala: H_o?=?0.680 and H_e?=?0.816; Babites: H_o?=?0.693 and H_e?=?0.815). The number of unique alleles per locus was 2.3 in Lake Kala and 0.6 in Lake Babites. The present study showed relatively high polymorphism of analysed microsatellite markers.