Abstract
Few studies of the ecology of Mediterranean saline streams exist. The strong selective pressure exerted by salinity greatly limits the presence of many taxa, Plecoptera (stoneflies) among them. However, a few species of stoneflies have been reported inhabiting saline streams, particularly components of the thermophilous biocoenosis seemed to have adapted to salinity pulses caused by fluctuations in annual rainfall. For two years, three sites within a saline stream, Arroyo Salado in southern Iberian Peninsula, were sampled to determine the stonefly species composition. Conductivity at the three sites ranged from 2290 to 87792, 2550 to 90824, and 206 to 2818 μS/cm, respectively. A total of seven different stonefly taxa were identified at the three sites: Brachyptera auberti Consiglio, Nemoura lacustris Pictet, Capnioneura libera (Navás), Tyrrhenoleuctra sp., Hemimelaena flaviventris (Pictet), Protonemura alcazaba Aubert, and Perla marginata (Panzer), the latter two only at the site where the stream flowed continuously and conductivity was lower. The possible strategies enabling these stonefly species to surviving in Arroyo Salado are discussed.