Antarctic anemones of the genus Halcampoides inhabit low intertidal and shallow subtidal zones. They readily burrow into soft sediments following disturbance. The process of re-burying was recorded using time-lapse video in the aquarium of the British Antarctic Survey with specimens of a species collected from the shallow sublittoral (<1 m depth) at Signy Island. Penetration of the sediment tak...

the influence of the herbivorous snail (physa sp.) on the algal periphyton community from thegamasiyab river, kermanshah province in western iran was examined by establishing a gradient of physa sp.density in artificial streams. the impact of physa grazing was evaluated by measuring dry mass, ash-free drymass (afdm) and chlorophyll a in the periphyton community. snails significantly depressed p...

Deciphering evolutionary processes occurring within contaminated populations is important for the ecological risk assessment of toxic chemicals. Whereas increased tolerance to contaminants is well documented in aquatic animal populations, whether such phenotypic changes occur through genetic adaptation is still debated. In that sense, several studies with the freshwater crustacean Gammarus conc...

Ovaries were taken from five sexually mature amphipods: Gammarus fossarum, Gammarus pulex, Gammarus roeseli, Hyallela azteca and Parhyale hawaiensis. The soluble proteome extracted from individual pair of ovaries from five biological replicates was trypsin digested and the resulting peptides were analyzed by high resolution tandem mass spectrometry. The spectra were assigned with four protein s...

Physa acuta Draparnaud, 1805 is an invasive gastropod that can affect local species. In Argentina, it is widespread and abundant, even in environments inhabited by the native species Stenophysa marmorata Guilding, 1828. Its predominance raises the question whether this could be explained by a more successful energy allocation in functional requirements (growth, reproduction and survival) compar...

در این مقاله حل دقیق ارتعاش برون صفحه‌ای نانو ورق‌های مستطیلی نسبتاً ضخیم براساس تئوری غیر‌محلی تغییر شکل برشی سینوسی اصلاح شده با نظر گرفتن شرایط مرزی لوی ارائه است. هدف اصلی تحقیق بررسی اثر مقیاس کوچک بر پارامترهای فرکانسی می‌باشد. برای توصیف تأثیرات خارج از صفحه‌ی ورق غیر محلی ارینگن استفاده شده. مشتمل شش حالت مختلف شامل دو ضلع موازی دارای تکیه‌گاه ‌ساده و اضلاع دیگر ترکیبی ساده، گیردار آزاد ...

Aquatic molluscs of three extensive nature reserves (Žabakor, Podtrosecká údolí, Údolí Plakánek) in the Český ráj Protected Landscape Area (northern Bohemia) were studied 2019. Altogether 33 mollusc species found at 40 sites including streams, fishponds, pools, and wetlands. Results compared with previous research. The occurrence endangered bivalves Sphaerium nucleus Pisidium amnicum was confir...

Room-temperature ionic liquids (ILs) are being promoted as environmentally friendly alternatives to volatile organic solvents currently used by industry. Because ILs are novel and not yet in widespread use, their potential impact on aquatic organisms is unclear. We studied the effects of several ILs on the survivorship and behavior (movement and feeding rates) of the freshwater pulmonate snail,...

concentration of heavy metals in aquatic ecosystems is considered as an important environmantal issue. in this study, the namrood river located in firoozkooh (tehran province, iran) was assessed for the existence of heavy metals. the namrood river is situated by the main road being by pollutants from tourism and recreational centers, gas stations, sewage of villages, agricultural wastewater and...