Female amphipods carry their eggs and offspring in a ventral brood pouch. Previous research has demonstrated that females of species inhabiting harsh environmental conditions expend additional energy in active parental care such as ventilating eggs by beating their pleopods. This study investigated whether similar forms of care could be detected in amphipods collected from spring fed ponds and streams. Two behaviors reported to function in parental care in other species were observed in ovigerous females, but were absent in nonovigerous females and males. Ovigerous females were also shown to beat their pleopods significantly longer than males or nonovigerous females, suggesting that this is another form of active parental care. The duration of pleopod beating varied considerably depending on both the season and the habitat from which the amphipods were collected. Differences were most pronounced for ovigerous females. Similarly, the duration of pleopod beating was significantly longer, especially for ovigerous females, when amphipods were placed in water with experimentally reduced levels of oxygen. These results suggest that even in habitats with high water quality, amphipods can show active parental care and that females have a phenotypically plastic response to environmental conditions in determining the amount of care provided. The potential fitness effect of such response may have important implications for water quality management.