Classification and identification of a freshwater jellyfish, Craspedacusta sowerbyi,found in Fuzhou

Craspedacusta species was a precious freshwater jellyfish, and was found sporadically in the world. As the parameters of morphological characteristic were always uncertain, the classification of the freshwater jellyfish had been still confused. A lot of freshwater jellyfish were found in a reservoir from a goldfish aquacultural farm in Fuzhou, Fujian Province, during September in 2013. Because the 18S rDNA molecular marker was important for the biological identification of freshwater jellyfish, morphological characteristic as well as 18S rDNA sequence analysis were used for the classification and identification. Results showed that the samples were with tubular statocyst, relatively long per-radial tentacle and nipple-like stenotele of bostrychoid or annular arrangement together with the same morphological characteristic as C.sowerbyi and its subspecies; The density of tentacles was 11.06±0.71, and the density of statocysts was 5.66±0.43, which were also consistent with the C.sowerbyi; The consensus sequence of 18S rDNA gene of samples and C.sowerbyi in GenBank revealed 99 % of identity. Therefore, the freshwater jellyfish isolated in Fuzhou was identified as C.sowerbyi Lankester, 1880.