Skull Morphology Variation as Related to Trophic Specialization in Three Forms of Salvelinus malma (Salmonidae) from the Kamchatka River Basin.

New data on the correlation between morphology and trophic specialization of three riverine charr forms from the Kamchatka River basin (stone charr, white charr, and Dolly Varden) are presented. The paper analyzes the food preferences of the fishes according to their stomach contents and retrospectively assesses their nutrition according to the ratio of stable nitrogen isotopes. The three charr forms are compared in terms of the head shape and structure of the cartilaginous skull for the first time. The correlation between the type of their nutrition and structural features of their skull is shown. Both general and specific adaptive features of the morphology of piscivorous stone and white charrs are revealed in comparison with benthivorous Dolly Varden.

Occurrence of sympatric charr groups, Salvelinus, Salmonidae, in the lakes of Kamchatka: a legacy of the last glaciations.

Six postglacial lakes were studied along both sides of the Kamchatka central mountain range, Russia. Pairs of local morphotypes of species of Arctic charrs, Salvelinus spp., have previously been described from the southernmost lakes while the fish fauna of the four northernmost lakes was studied here for the first time. Phenotypic data support the division of Kamchatkan lacustrine charrs into two groups according to the number of gill rakers and pyloric caeca, as well as snout-dorsal and snout-ventral distances (MANOVA, P < 0·001). These groups respectively correspond to phenotypes commonly referred to as Salvelinus malma and Salvelinus taranetzi. To clarify the identity of these groups, D-loop and cytochrome b (cytb) region sequences were analysed. Haplotype network analysis of mtDNA shows the salmonids inhabiting four lakes on the south and north are phylogenetically close to either Beringian S. malma or to S. taranetzi from the Chukotka and Kolyma River basins (the mean ± s.e. pairwise per cent sequence divergence is 0·006 ± 0·001). Phenotype-genotype discordance suggests that mitochondrial introgression between species has occurred in the two smallest lakes (<0·5 km2 ) in the central part of the peninsula. Identical haplotypes of D-loop and cytb regions were found for the populations of S. taranetzi from the most distant southern and northern lakes, indicating all lakes were colonized by both species simultaneously after the last glacial maximum. Salvelinus taranetzi may have colonized the Kamchatka peninsula from one or both of two different source regions: the Arctic Beringia and the northern coast of the Okhotsk Sea.

Clinical, laboratory and ultrasound thanges in early manifestations of rheumatoid arthritis.

Complex analysis of changes in clinical, laboratory and ultrasound manifestations in rheumatoid arthritis revealed relationships between the pathologic process activity, the disease duration, its X-ray stage and ultrasound signs. Manifestation of rheumatoid arthritis is characterized by predominant proliferation and exudation in soft tissues inside joints, tendopathies, chondral plate alterations as hyaline destruction. Articular cartilage erosions can be seen even in 2.8 months after destructive arthritis manifestation. Diagnostic criteria of early rheumatoid arthritis are: articular disorders location, articular syndrome variant (mono-, oligo- and polyarthritic; seropositiveness on rheumatoid factor andACCP), chondral plate state according to ultrasound examination.

Structure of "species flocks" in fishes: Channels of the splanchnocranium divergence in endemic lacustrine benthivorous charrs (Salvelinus, Salmonidae, Teleostei) in Lake Kronotskoye, Kamchatka.

The structure of splanchnocranium bones has been studied in four endemic benthivorous charrs (the genus Salvelinus) from Lake Kronotskoe (Kamchatka). It has been found that, according to the whole set of characters of the splanchnocranium structure, the most expressed differences are observed between specialized forms, nosed and largemouth charrs, inhabiting different biotopes of the lake. Differences between small-mouth and white charrs are less pronounced, and the species are characterized by generalized features of the structure of jaws. It can be suggested that, in addition to diverse feeding preferences within a feeding niche, an extremely high diversity of charrs in Lake Kronotskoe is due to a complex geomorphological structure of the water system. Thus, the "species flock" comprising a complex set of diverse benthivorous morphotypes has been formed and exists in Lake Kronotskoe. Charrs from Lake Kronotskoe are a representative example of sympatric speciation by way of formation of new forms differing from each other in morphological, ecological, and trophic features.

[Developmental abnormalities in salmonids (Salmonidae) under the conditions of large-scale volcanic pollution of their spawning ground (using dolly varden Salvelinus malma as an example)].

Rivers originating from the areas of active volcanism in Kamchatka serve a spawning ground for anadromous and resident populations of dolly varden (Salvelinus malma). In some cases, watercourses with a long-term continuous spawning of S. malma are subjected to chronic pollution with dissolved toxicants and suspended mineral particles. The revealed development conditions range from background ("clean" rivers) to critical (most "polluted" rivers). Medium pollution leads to the development of hatchlings with abnormalities in the ethmoidal head segment, lower jaw, operculum, lobes of the paired fins, and axial skeleton (up to 40% of all specimens). Delayed ossification of skeletal elements takes place. Abnormalities in the development of spinous processes occur more often (up to 49-55% compared to 25-30% in the background areas). The average number of asymmetries per specimen.(in four bilateral structures) increases from 1.1-1.4 to 1.7- 2.5. Similar developmental abnormalities have been registered in underyearlings, both anadromous and resident, influenced by various pollutant combinations. While fish continue to grow, some of them die because of abnormalities; thus, their frequency in 3-year-old specimens nears the background one. Upon extreme pollution, deviant specimens are sampled at earlier developmental stages and characterized by a lower frequency of morphological abnormalities.