for comparison of the food value of four different epecies of aquatic weeds: potamogeton pectinatus , potamogeton lucens, potamogeton perfoliatus, najas minor and two species of terrestrial grass: medicago sativa and cynodon dactylon by grass carp (ctenopharyngodon ideda), was studied in the shahicl rejai fishfarm in sari (province of mazandaran). totally 6 concrete ponds with 30 cubic meter vo...

Invasive plant species are among the major threats to freshwater biodiversity. Few experimental studies have investigated whether native plant diversity can provide biotic resistance to invaders in freshwater ecosystems. At small spatial scales, invasion resistance may increase with plant species richness due to a better use of available resources, leaving less available for a potential invader...

A hydroponic experiment was performed to investigate the stress responses and biochemical adaptations of four submerged macrophytes, Potamogeton crispus, Myriophyllum spicatum, Egeria densa, and Potamogeton oxyphyllus, to the combined exposure of hypoxia and hydrogen sulfide (H2S, provided by NaHS). The investigated plants were subjected to a control, hypoxia, 0.1mM NaHS, 0.5 mM NaHS, 0.1 mM Na...

Acoustic telemetry was utilized to track 49 brown trout (Salmo trutta) and 37 Arctic charr (Salvelinus alpinus) first-time migrants of wild origin [post-smolts; mean LF (fork length): 169 172 mm] in a large fjord northern Norway. The S. trutta were registered at sea for more than twice the time alpinus (medians 54 22 days, respectively). Both species mostly detected near river mouths (>80% dete...

In closed aquatic environments like ponds or lakes, water bloom caused by eutrophication has severely damaged aquatic ecosystems. Some previous studies suggested that submerged macrophytes contribute to the development of aquatic ecosystems and water purification. Although water purification and lake ecosystem restoration using submerged macrophytes have been greatly studied, their specific mec...