Marine fungus <Emphasis Type="Italic">Stilbella aciculosa</Emphasis> as a potential producer of prostaglandins

The amount and composition of fatty acids in the fungus Stilbella aciculosa associated with the marine macroorganism Apostichopus japonica (trepang) were determined by gas-liquid chromatography and gas chromatography-mass spectrometry. In the culture liquid of S. aciculosa, prostaglandins (PG) of groups E and F were revealed by UV spectroscopy. This finding was confirmed by the presence of direct precursors of PG, polyunsaturated eicosapentaenoic and docosahexaenoic acids, in the culture liquid. The biomass of this fungus contained PG of group B.     

Seasonal changes in the content of lipids and photosynthetic pigments in a brown alga Saccharina cichorioides

Seasonal changes in the contents of lipids and photosynthetic pigments (PSP) were investigated in a brown alga Saccharina cichorioides Miyabe (Phaeophyceae, the family Laminariaceae). The content of lipids varied from 0.27 to 0.60% of the algal fresh weight. The content of glyceroglycolipids (GL) was much greater in the time of spore formation (June–July and September–October), phospholipids — in the spring and in September–October, and the content of neutral lipids — in the spring and in November. In the period of spore release (August and October), the level of GL and polyunsaturated fatty acids (PUFA) sharply decreased. A high level of PUFA was observed from March to July and in November. In August and October, the same as in the spring, the proportion of saturated fatty acids (FA) was great. The content of chlorophylls from March to November varied from 20.3 to 26.9%, and the level of carotenoids — from 10.7 to 16.1%. Total content of PSP was relatively high in March and in August–September. Free sterols accounted for 3.4–7.3% of total lipids; their proportion was greater in spring than in summer and autumn.     

Diversity of nosed charrs <Emphasis Type="Italic">Salvelinus malma</Emphasis> (Salmonidae) of Lake Kronotskoe (Kamchatka)

The littoral benthivorous charrs Salvelinus malma with subterminal mouth distributed in Lake Kronotskoe basin are separated into three distinct morphs. These morphs significantly differ in head proportions, jaws' length, skull structure, and degree of gill rakers' reduction. The morphs spawn in distant lake tributaries at the spawning grounds of various types. Joint spawning has never been observed for these morphs in any type of spawning grounds. The differences in the external morphology and growth rate of the morphs become evident during the riverine life stage. The adult charrs inhabit the same sites of the littoral zone. No reliable difference is found in the diet among morphs, since all nosed charrs dominantly feed on amphipods with the exception of a few individuals that fed on chironomid larvae.     

New endemic deepwater charr morphs of the genus <Emphasis Type="Italic">Salvelinus</Emphasis> (Salmoniformes: Salmonidae) from Lake Kronotskoe,Kamchatka

Two previously unknown profundal dwelling charr morphs of the genus Salvelinus from Lake Kronotskoe are described in this article. According to their lifestyle peculiarities, these morphs were named the “bigmouth charr” and “smallmouth charr.” The former group is near-bottom benthivorous, while the latter one inhabits the water column and occupies the omnivorous niche. Bigmouth and smallmouth charrs are distinguished from the rest of the sympatric charr morphs by their smaller size, shorter snout, larger eyes, as well as by several craniological traits and lower parasite abundance. Spawning of both morphs takes place directly in the profundal zone and lasts from late October to February. Additional studies are required to determine the systematic status of the new morphs.     

Ecological differentiation of resident Dolly Varden <Emphasis Type="Italic">Salvelinus malma</Emphasis> (Salmonidae) from Lake Dal’nee,Kamchatka

Resident Dolly Varden Salvelinus malma of Lake Dal’nee (Paratunka River basin) is represented by two stable trophic groups: one group feeds on mainly amphipods while another on gastropods. The former group is dominantly infected by Cyathocephalus truncatus and Crepidostomum metoecus, whereas the latter group is infected with Crepidostomum farionis, Ichthyocotylurus erraticus, and Diplostomum spp. The fishes of the former group grow faster and defined by higher fat content of muscular tissue. In addition, they accumulate monoenic fatty acids in the muscles. The fishes of the latter group differ in a high content of omega-3 and omega-6 fatty acids in the muscles. The amphipod foragers are characterized by a larger head with elongated upper jaw and comparatively short fins. A similar ecological differentiation is observed in the littoral benthivorous charrs from Lake Kronotskoe. The group feeding on amphipods was found in both lakes. In Lake Kronotskoe, the second group consumes the most abundant sedentary benthos, mollusks and chironomids.