Analysis of microsatellite variation in the rainbow trout <Emphasis Type="Italic">Parasalmo (Oncorhynchus) mykiss</Emphasis> from Kamchatka

Genetic variation of Kamchatka rainbow trout Parasalmo (O.) mykiss was examined using 10 microsatellite DNA loci, and phylogeographic comparison with other representatives of the species across the distribution range was performed. It was demonstrated that Kamchatka populations differed from other geographic groups of rainbow trout in a number of microsatellite loci. These populations also displayed distinct clustering and were characterized by lower genetic diversity. Analysis of a set of 26 different microsatellite loci (personal and literature data) demonstrated that most of the populations within the Kamchatka region were separated from one another, characterized by marked geographic differentiation, and affiliation to certain river basins. In Kamchatka rainbow trout, with high degree of probability, three geographic clusters (northwestern, southwestern, and eastern) were identified. In general, analysis of microsatellite DNA supported the data on low genetic diversity of the Kamchatka group Parasalmo (O.) mykiss, based on the variation estimates for a number of genes of nuclear and mitochondrial DNA, and allozyme loci.     

Fungi are involved in the effects of litter mixtures on consumption by shredders

1. Decomposition of litter mixtures in both terrestrial and aquatic ecosystems often shows non‐additive diversity effects on decomposition rate, generally interpreted in streams as a result of the feeding activity of macroinvertebrates. The extent to which fungal assemblages on mixed litter may influence consumption by macroinvertebrates remains unknown. 2. We assessed the effect of litter mixing on all possible three‐species combinations drawn from four tree species (Alnus glutinosa, Betula pendula, Juglans regia and Quercus robur) on both fungal assemblages and the rate of litter consumption by a common shredder, Gammarus fossarum. After a 9‐week inoculation in a stream, batches of leaf discs were taken from all leaf species within litter mixture combinations. Ergosterol, an indicator of fungal biomass, and the composition of fungal assemblages, assessed from the conidia released, were determined, and incubated litter offered to G. fossarum in a laboratory‐feeding experiment. 3. Mixing leaf litter species enhanced both the Simpson’s index of the fungal assemblage and the consumption of litter by G. fossarum, but had no clear effect on mycelial biomass. Specifically, consumption rates of J. regia were consistently higher for mixed‐species litter packs than for single‐species litter. In contrast, the consumption rates of B. pendula were not affected by litter mixing, because of the occurrence of both positive and negative litter‐mixing effects in different litter species combinations that counteracted each other. 4. In some litter combinations, the greater development of some fungal species (e.g. Clavariopsis aquatica) as shown by higher sporulation rates coincided with increased leaf consumption, which may have resulted from feeding preferences by G. fossarum for these fungi. 5. Where litter mixture effects on decomposition rate are mediated via shredder feeding, this could be due to indirect effects of the fungal assemblage.     

An Analysis of Microsatellite Polymorphism in the Population of the Arctic Rainbow Smelt Osmerus dentex from Eastern and Western Kamchatka

Russian Journal of Genetics - The genetic diversity of ten microsatellite loci is examined in samples of Arctic rainbow smelt. The expected heterozygosity estimates vary in the range of...     

Clusters of Repetitive DNA Sequences in Chromosomes of Voles of the Subgenus Microtus (Microtus,Arvicolidae)

Russian Journal of Genetics - The study is focused on the analysis of the mechanisms underlying the formation and distribution of repeat clusters in mammalian chromosomes, as exemplified by a group...     

Ligophorus pilengas Sarabeev & Balbuena, 2004 (Monogenea: Ancyrocephalidae) is proposed as the senior synonym of L. gussevi Miroshnichenko & Maltsev, 2004

Ligophorus pilengas Sarabeev & Balbuena, 2004 and L. gussevi Miroshnichenko & Maltsev, 2004, both recently described as new species from the so-iuy mullet Mugil soiuy in the Sea of Azov and Black Sea, were compared. A morphometric analysis of both forms strongly suggests that they represent the same species. According to the 'Principle of priority', L. pilengas is proposed as a senior synonym of L. gussevi.