Monthly Archives: April 2015

See our last paper!!! Pallarés et al. 2015

The comparative osmoregulatory ability of two water beetle genera whose species span the fresh-hypersaline gradient in inland waters (Coleoptera: Dytiscidae, Hydrophilidae)

Pallarés S, Arribas P, Bilton DT, Millán A, Velasco J (2015)
PLoS ONE 10(4): e0124299.

A better knowledge of the physiological basis of salinity tolerance is Nebrioporus baeticus (2)essential to understanding the ecology and evolutionary history of organisms that have colonized inland saline waters. Coleoptera are amongst the most diverse macroinvertebrates in inland waters, including saline habitats; however, the osmoregulatory strategies they employ to deal with osmotic stress remain unexplored. Survival and haemolymph osmotic concentration at different salinities were examined in adults of eight aquatic beetle species which inhabit different parts of the fresh—hypersaline gradient. Studied species belong to two unrelated genera which have invaded saline waters independently from freshwater ancestors; Nebrioporus (Dytiscidae) and Enochrus (Hydrophilidae). Their osmoregulatory strategy (osmoconformity or osmoregulation) was identified and osmotic capacity (the osmotic gradient between the animal’s haemolymph and the external medium) was compared between species pairs co-habiting similar salinities in nature. We show that osmoregulatory capacity, rather than osmoconformity, has evolved independently in these different lineages. All species hyperegulated their haemolymph osmotic concentration in diluted waters; those living in fresh or low-salinity waters were unable to hyporegulate and survive in hyperosmotic media (> 340 mosmol kg-1). In contrast, the species which inhabit the hypo-hypersaline habitats were effective hyporegulators, maintaining their haemolymph osmolality within narrow limits (ca. 300 mosmol kg-1) across a wide range of external concentrations. The hypersaline species N. ceresyi and E. jesusarribasi tolerated conductivities up to 140 and 180 mS cm-1, respectively, and maintained osmotic gradients over 3500 mosmol kg-1, comparable to those of the most effective insect osmoregulators known to date. Syntopic species of both genera showed similar osmotic capacities and in general, osmotic responses correlated well with upper salinity levels occupied by individual species in nature. Therefore, osmoregulatory capacity may mediate habitat segregation amongst congeners across the salinity gradient.

Download Pallarés et al. 2015

Winner of the EFFS PhD Dissertation Award (2013-2014)

Resolution of EFFS Award for the best PhD Dissertation in Freshwater Sciences (2013-2014)

EFFSThe European Federation for Freshwater Sciences (EFFS) Board of Representatives is proud to announce the successful applicants for the first EFFS Award for the best PhD Dissertation in Freshwater Sciences (2013-2014). An international jury, composed of five members of the International Representatives of EFFS, have evaluated the pre-selected dissertations, which had been transmitted by the National Societies. Three candidates have been selected for the prizes.

Main prize and winner of the EFFS Award for the best PhD Dissertation in Freshwater Sciences:
French National Institute for Agronomic Research (INRA), UMR CARRTEL, Thonon-les-Bains, France
for the doctoral thesis entitled
“Freshwater dsDNA viral diversity: A special emphasis on viruses infecting phytoplankton (cyanophages and phycodnaviruses) and T4-like myophages in peri-alpine lakes”

The two subsidiary prizes go to:
Department of Ecology and Hydrology – University of Murcia, Spain.
for the doctoral thesis entitled
“Evolutionary ecology, biogeography and conservation of water beetles in Mediterranean saline ecosystems”
and to:
Dr. Arunava PRADHAN
University of Minho, Portugal
for the doctoral thesis entitled
“Impacts of nanoparticles to microbes and invertebrates: from community responses to cellular targets”