Behavioral response is commonly affected by heavy metal toxicity, and behavioral reaction can be measured as sensitive endpoint for sublethal toxicity test and obtained easily and quickly. Also behavioral endpoints may serve as an insightful evaluation tool of the ecological effects of toxic chemicals. In this study, Heterocypris incongruens (Crustacea: Ostracoda) was selected, which is usually used as an indicater species for water quality. H. incongruens was exposed to copper and arsenic for 5 minute and total distance, velocity, turn angle, and angle velocity were measured for 30 minute using video analysis system in laboratory condition. Each endpoints reflected the effects of copper and Arsenic toxicity appropriately. These endpoint have possibility that can be used to identify characteristic behavioral responses to metal toxicity.

We evaluated the effect of water pH (6, 7, 8 and 9) and hardness (40mg/L and 160mg/L as CaCO3) on the growth of H. incongruens. Both water pH and hardness affected the growth parameter of H. incongruens such as head capsule width and maturity time. The head capsule width of the adults in the highest ph condition was 9.7% increased compared to the lowest ph condition. The maximum difference of the maturity time was 192 hours among the test conditions. Overall, as water ph level increase makes head capsule size of the test animal large, the inter-molt period and maturity time become shorter significantly. The effect of water hardness increasing showed a similar tendency with ph level. Especially, the difference of the growth parameter among the test conditions was increased by growing test animal. There are strong correlation between available amount of intake calcium and growth parameters of test animal. These results indicate that because of calcium demand for growth, water pH level and hardness are the important effect factor in life-cycle of the H. incongruens..

Proteomics may help to detect subtle pollution-related changes, such as responses to mixture pollution at low concentrations, where clear signs of toxicity are absent. Also proteomics provide potential in the discovery of new sensitive biomarkers for environmental pollution. We utilized SELDI-TOF MS (surface enhanced laser desorption. / ionization time-of-flight mass spectrometry) to analyze the proteomic profile of Heterocypris incongruens exposed to several heavy metals (lead, mercury, copper, cadmium and chromium) and pesticides (emamectin benzoate, endosulfan, cypermethrin, mancozeb and paraquat dichloride). Several highly significant biomarkers were selected to make a model of classification analysis. data sets obtained from H. incongruens exposed to pollutants were investigated for differential protein expression by SELDI-TOF MS and decision tree classification. Decision tree model was developed with training set, and then validated with test set from profiling data of H. incongruens. Machine learning techniques provide a promising approach to process the information from mass spectrometry data. Even thought the identification of protein would be ideal, class discrimination does not need it. In the future, this decision tree model would be validated with various levels of pollutants to apply field samples.

Soil contamination can be one path for stream and groundwater contamination. In this study, the toxicity of soils sampled in the vicinity of the abandoned mine located in the Gyeonggi province was evaluated using freshwater organisms Heterocypris incongruens. Two different exposure scenarios, one is in the aqueous only exposure, and the other is in the aqueous + soil exposure. The seven different soil samples were tested depending on the contamination level; reference (1 soil), moderately contaminated (4 soils) and highly contaminated (2 soils). In the toxicity tests, H. incongruens were exposed to water extracts (aqueous only exposure) and soils (aqueous + soil exposure) which were serially two-fold diluted with either EPA moderate hardwater or clean sand, respectively. After 6 days of exposure, no significant impact on the survival was found in the both systems for reference soil, while only significant impact was found in the aqueous + soil system for moderately contaminated soil. And the survival of H. incongruens was dramatically decreased with decreasing dilution series for highly contaminated soils. Interestingly, the toxicity of aqueous + soil system was higher than that of aqueous only system, implying the exposure of chemicals to H. incongruens may be a consequence of its foraging behavior onto the surface of sediment. From the results of this study, the freshwater organism H. incongruens can be used as surrogate test species to assess the soil contamination.

Male cicadas produced species-specific calling songs to attract conspecific receptive females. Male cicadas typically occupy tree trunks or tree branches during calling song production. We studied calling site preference in four species of cicada: Cryptotympana dubia, Meimuna opalifera, Oncotympana fuscata, and Meimuna mongolica. Several males were observed to sing together in a tree in C. dubia, but males of other species tended to sing singly in trees. There were also cases in which two or three individuals of different species sang together in a tree. Species differed significantly in height of and distance to trunk from calling site. Both tree height and tree crown were significant factors for calling site preference. The height of calling site was the highest in C. dubia, followed by M. opalifera, M. mongolica, and O. fuscata. The distance to trunk from calling site in M. opalifera was the farthest and was significantly different from those of other species. Males of other species tended to sing close to tree trunks. Males of M. opalifera were mobile when they produced calling songs, whereas males of other species were stationary. That is, males of M. opalifera sang only for short periods of time and moved around adjacent trees. Segregation of calling sites suggests that these four cicada species occupy different sections of trees, thereby avoiding competition for calling sites.

Traditionally oxygen demands and concentrations of variable pollutant have been used for the assessment of lentic or lotic water quality. But there is a high probability that newly synthesized chemicals flow into the aquatic ecosystem, and it is very hard to investigate that many kinds of chemicals interact even though they exit at lower level than legal standards. As a consequence of limitation of chemical assessment for media, biological assessment techniques for accepters which are affected by pollutants or physicochemical properties have been developed. However, it still has several weak points because it does not have the ecological relevances using the internationally standard test species which do not inhabit Korea. Besides, the assessment using just one or two species may have a possibility of overestimation or underestimation because a certain species can be extremely sensitive or insensitive to a certain chemical or physicochemical property. Therefore, we used four kinds of indigenous aquatic invertebrates to assess the local stream quality and integrated their responses into a new index which ranges from 0(bad) to 1(good). We assessed four streams throughout Ansan and one stream in Gapyeong, and index values of two streams near residential and industrial area in Ansan were under 0.9 and the others were over 0.9.