Charrs of the genus Salvelinus form distinct trophic morphs living in sympatry in numerous postglacial lakes. Here we demonstrate that charrs can diversify into amphipod foraging specialists and sedentary macrobenthos consumers in the shallow-water ecosystems. This pattern was revealed in three out of six lakes under exploration supported by differences in stomach content, trophic-transmitted parasite, and stable isotope ratio analyzes. The body shape and growth rate comparison indicates that this kind of trophic-based diversification emerges at a juvenile stage and is maintained throughout the whole life. The restriction in gene flow found between the morphs allows to propose the possibility for the hereditable-based specialization to evolve. We found that those diversification phenomena are possible only in the lakes situated in vicinity of the ocean coastline, while no evidence of this split was found for inland mountain lakes. We suggest that the trophic-based diversification in the littoral ecosystems is accounted for the heterogeneity in the ecological conditions and food resources’ distribution linked to coastal wind action. This phenomenon was previously reported for the charr in Lake Fjellfrosvatn, Scandinavia, so it seems to be some universal yet poorly described kind of disruptive selection pressure for northern latitude fishes.
Biology Bulletin - The content of nonspecific immune complexes, products of lipid peroxidation, and antioxidant activity in the liver, kidney, and spleen were studied in Salvelinus schmidti, S.... 相似文献
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. 相似文献
We compared the content of total lipids, particular lipid classes, fatty acids (FAs), and pigments in the brown alga Costaria costata [Turn.] Saund (Laminariaceae) in different seasons: during algal active life (April–June) and in the beginning of their degradation
(the end of July). Lipids comprised only a small part of algal extractable compounds (10.9–13.4%). Their higher content was
observed in May, in the period of alga preparation to sporogenesis. Polar lipids, glyceroglycolipids (GL) and phospholipids
(PL), comprised a great part of total lipids in spring months and June, whereas neutral lipids, in July. GL predominated in
polar lipids in spring and summer. The highest content of GL was observed in May and PL in April. Storage lipids comprised
a great part of lipids in July. The content of sterols was the highest in April and May. In summer months, the content of
sterols decreased and remained on unchanged level until thallus degradation. Polyunsaturated FAs (PUFAs) comprised the most
part of FAs. Their highest content was observed in April. The main part of PUFAs were those of ω-3 series. In July, the level
of these PUFA decreased substantially. The levels of ω-6 PUFAs were approximately similar in spring and summer months. The
lowest content of monounsaturated FAs was detected in April; in May and July; the relative content of these FAs increased
sharply. We also detected seasonal changes in the content of pigments and the ratios between them. 相似文献
Seasonal changes in the contents of lipids and photosynthetic pigments (PSP) in the brown alga Undaria pinnatifida (Harvey) Suringar (Phaeophyceae, Alariaceae) on different stages of its growth were studied. Lipids of all plant growth group
comprised glyceroglycolipids (GL), phospholipids, and neutral lipids (NL). The ratio between these lipid groups and the content
of particular lipids depended on the season and algal growth stage: NL predominated in seedlings; juvenile algae comprised
approximately similar amounts of NL and GL; and in adult algae, GL predominated. In winter and spring, algal tissues contained
relatively more free sterols than in summer. Total lipid content in seedlings and juvenile algae was higher then in adult
plants. Lipid fatty acid (FA) composition was similar on all growth stages, but the content of major components differed;
this is mainly related to 18:4 n-3, 20:4 n-6, and 20:5 n-3 acids. The predominant FAs in seedling lipids were saturated FAs,
whereas in the lipids of juvenile and adult algae, polyunsaturated FAs predominated. 相似文献
The biological activity of lipids and photosynthetic pigments of the kelp Sargassum pallidum (Turner) C. Agardh has been studied. Free fatty acids and their esters demonstrated considerable antimicrobial activity against bacteria (Staphylococcus aureus and Escherichia coli), yeast-like fungi (Candida albicans), and opportunistic pathogenic (Aspergilius niger) and phytopathogenic (Fusarium oxysporum, and Septoria glycines) fungi. Glyceroglycolipids and neutral lipids demonstrated moderate activity. Fucoxanthin and chlorophylls weakly suppressed the growth of microorganisms. None of the studied substances demonstrated activity against Ehrlich’s carcinoma. It was shown that the season of weed harvesting affected both antimicrobial and hemolytic activities of different lipids due to changes in their fatty acid composition. 相似文献
The liver, gonads, gills, and muscles of five trophically distant charr morphs from Lake Kronotskoe, as well as silty sediments of the lake, were tested for trace-element contents. Concentrations of Mn, Fe, Ni, Cu, Zn, Rb, Sr, As, and Se were detectable in the fish tissues, while the xenobiotics Hg, Cd, and Pb were not determined. The current data indicate a strong correlation between trace-element content and the ecology of each morph and no relationship to the fish length. In the majority, the Ni, Cu, and Zn levels were strongly dependent on trophic biology. The contents of Rb, Mn, and Se were dependent on the distribution of the charr morphs along the depth gradient and correlated with the accumulation of these elements in the bottom sediments. 相似文献
Antimicrobial and hemolytic activity of ethanol extract of brown seaweed Laminaria cichorioides (Miyabe), its lipophilic fractions, various classes of substances of lipophilic fraction, such as chlorophylls, fucoxanthin,
monogalactosyldiacylglycerols, digalactosyldiacylglycerols, sulfoquinovosyldiacylglycerols, and fatty acids were investigated.
The antimicrobial activity was studied by means of yeast cells Safale S-04 and Candida albicans KMM 455, fungi Aspergillus niger KMM 4634 and Fusarium oxysporum KMM 4639, bacteria Staphylococcus aureus ATCC 21027 (gram-positive) and Escherichia coli ATCC 15034 (gram-negative) which demonstrated selective sensitivity to the studied substances. Hemolytic activity was investigated
at concentrations of substances in the range of 0.2–200 μg/ml at different pH of erythrocyte suspension. All investigated
substances caused hemolysis. The dependence of hemolytic activity of substances on pH of media was determined. 相似文献
Biological (antimicrobial, cytotoxic, embryotoxic, and hemolytic) activity of total lipids, individual fractions and classes of lipids, and photosynthetic pigments of Saccharina cichorioides (Miyabe) were studied, together with the effect of season of the alga harvesting and changes in fatty acid composition of lipids on their activity. Antimicrobial activity was more pronounced in total lipids, individual fractions of lipids, and photosynthetic pigments of S. cichorioides collected in March. High antimicrobial activity was also demonstrated by total lipids of alga samples collected in September and November and hemolytic activity, in those collected in March and November. Pronounced hemolytic activity was demonstrated by some classes of glyceroglycolipids of laminaria samples collected in November. Cytotoxic activity toward mouse splenocytes was demonstrated only by total lipids of alga collected in March. Toxic effects toward embryos of sea urchin were demonstrated by lipids of S. cichorioides collected in June and September. None of the lipids or pigments was active against Ehrlich ascites carcinoma. 相似文献
The contents of lipids and pigments were compared in juvenile and adult algae Costaria costata [Turn.] Saund (Laminariaceae) collected in April. The total content of lipids and that of particular lipid classes increased
markedly with age. In adult algae, the contents of total lipids, glyceroglycolipids, and neutral lipids doubled as compared
with juvenile algae and was equal to 5.70, 1.78, and 0.81 mg/g fr wt, respectively. The content of free sterols increased
with age by three times; it was equal to 0.11 mg/g fr wt in juvenile algae and 0.38 mg/g fr wt in adult algae. Total content
of phospholipids changed with age to a lesser extent: 0.72 mg/g fr wt in juvenile vs. 0.92 mg/g fr wt in adult algae. Substantial
changes were observed in the content of particular polar lipids. The absolute amounts of monogalactosyldiacylglycerols, sulfoquinovosyldiacylglycerols,
digalactosyldiacylglycerols, phosphatidylcholines, phosphatidylglycerols, and phosphatidylinosites increased markedly with
age, whereas the amount of phosphatidyl-O[N-(2-hydroxyethyl)glycines] declined. The amount of phosphatidylethanolamines did not depend on algal age. A small amount of
diphosphatidylglycerols was detected only in juvenile algae. The content of photosynthetic pigments (carotenoids and chlorophylls)
approximately doubled with age and, in adult algae, was equal to 0.57 and 1.23 mg/g fr wt, respectively. Total lipids of juvenile
and adult algae did not differ in fatty acid composition. At all developmental stages, polyunsaturated fatty acids predominated
early in spring and comprised about 80% of fatty acids. The acids of ω-3-series predominated among them. 相似文献