To understand the possible effects of changes in ambient temperature on spatialdistribution and ecology of ostracods, samples were randomly collected from 70aquatic sites with 12 different habitat types from Hatay (Turkey) province duringthe summer season of 2012. 14 of 19 ostracod species were newly reported forthe province. The first two axes of CCA explained 79.7% of the cumulativevariance of the relationship between the 12 most common species and fiveenvironmental variables. Accordingly, water temperature and electricalconductivity were the most effective factors on species occurrences (p<0.05).Estimating ecological optimum and tolerance values of species revealed thatHerpetocypris chevreuxi and Cypridopsis vidua displayed the lowest and highesttolerance values for water temperature, respectively. TWINSPAN resultsillustrated that ostracod species can be used to determine characteristics of habitatconditions. Indeed, the co-occurrence of H. chevreuxi with one or morecosmopolitan species is the indication of an increase in salinity and temperaturevalues. Results suggested that temperature changes can cause critical alteration inshallow water bodies where species with lower ecological tolerances willeventually be negatively affected. Therefore, such species, which may be called“potential candidate species for local extinction” will either be eliminated fromthe habitats in short term or become extinct in long term.