Taxonomical Study on Freshwater Copepods and Morphological Abnormalities

Abstract

Morphological feature is one of most important information in biology. This study focuses on the taxonomy and morphological abnormalities of copepod. Morphological feature and habitat information of 21 species were studied. 8 new species were descripted and morphological key of Palaearctic copepods were provided. Additionally, DNA sequence extraxted from 2 species were provided. Abnormalities, typically in swimming appendages and caudal rami, was observed in natural conditions and induced toxicities. The patterns of abnormalities were diverse, with the reduction, addition, or modification of seta and the fusion or transform segment. Abnormalities were shown in specific types and percentages relative to their stress level. The rate and pattern of deformities were also variable and it showed even low concentration of toxicity. As these traits are clearly distinguishable, I suggest its possible application in ecotoxicological monitoring.