02438nas a2200157   4500008004100000245018500041210006900226300001300295490000800308520178000316653000902096100001702105700001602122700001402138856012802152       1997                        eng d00aField distribution and sulphide tolerance of <i>Capitella capitata </i>(Annelida: Polychaeta) around shallow water hydrothermal vents off Milos (Aegean Sea): A new sibling species?0 aField distribution and sulphide tolerance of iCapitella capitata  a447-453.0 v1303 a The cosmopolitan polychaete Capitella capitata, known as a complex of opportunistic sibling species, usually dominates the acrobenthos of polluted or unpredictable environments. A population of C. capitata, termed Capitella sp. M, was found in a shallow water hydrothermal vent area south of Milos  (Greece). Here, this population occurs close to vent outlets (termed the "transition zone"), an environment with steep gradients of temperature, salinity and pH and increased sulphide concentrations of up to 710 mu-M. The  field distribution of C. capitata in relation to sulphide concentrations around the vent outlets was investigated and sulphide tolerance experiments  were conducted on laboratory-cultured worms to elucidate possible adaptations of Capitella sp. M to these extreme environmental conditions. In order to investigate whether the population from the Milos hydrothermal vent area can  be considered a distinct sibling species within the C. capitata complex,  crossbreeding experiments and analysis of general protein patterns were  conducted with Capitella sp. M and three other C. capitata populations of different ecological ranges. Capitella sp. M showed high resistance (median  survival time: 107 +- 38 h) to anoxia plus high sulphide concentrations of 740 mu-M. It seems that the ability to survive high-sulphide conditions in  combination with reduced interspecific competition enables the olychaete to  maintain a continuous population in this rigorous habitat. From the extremely  high tolerance to anoxia and sulphide, shown in both the crossbreeding experiments and the analysis of total proteins, it can be concluded that Capitella sp. M from the Milos hydrothermal vent area represents a separate sibling species within the C. capitala complex.10aKAPE1 aGamenick, I.1 aAbbiati, M.1 aGiere, O.  uhttps://icgf.myspecies.info/content/field-distribution-and-sulphide-tolerance-capitella-capitata-annelida-polychaeta-around