Influence of temperature and salinity on the survival of some benthic invertebrates in laboratory conditions

Separating sea bays create a complex habitat forcing its denizens to quickly adapt to changing conditions different from those in the sea: salinity, temperature, chemical composition etc. Animals vary in tolerance of changing life conditions. Thus, investigating the borders of adaptive abilities in the animals living in these waters is extremely interesting and allows us to better understand the functioning of both marine and continental water ecosystems.
In this study, we have chosen several marine, brackish and freshwater inhabitants in order to study their adaptation potentials under laboratory conditions. The animals were kept in water mixtures with a salinity range of 0-24 psu and at different temperatures. Three Gammaridae species showed different salinity preferences: G. lacustris only survived in fresh and slightly brackish water, M. obtusatus did not tolerate any freshening, while G. oceanicus showed a wide range of salinity tolerance.
Chironomus salinarius showed high mortality in the laboratory. Coleopterans demonstrated no preferences in salinity. Amphipods survived better at low temperatures, chironomides and beetles at room temperature. High temperatures (30 degree C) are detrimental to all subjects regardless of salinity. At low temperatures, (0...4 degree C), amphipods stand a greater range of salinities than at higher temperatures.