The morphology of seven specimens of Chrysaora chinensis (Scyphomedusae, Semaestomae) obtained from four sites off the coast of Peninsular Malaysia was examined. Morphological characteristics of C. chinensis that encompasses structures such as the bell, tentacles, oral arms, stomach, manubrium, radial canals and gonads were described in detail. A total of 107 specimens that represented C. chinensis populations of four coastal areas of Peninsular Malaysia (East-Central, East-North, West-Central, and West-North) were also analysed for shape variation using geometric morphometric analysis. Procrustes superimposition, Principal Component Analysis (PCA) and Canonical Variate Analysis (CVA) were applied to the images of gastrovascular pouches of C. chinensis to extract the shape information. Independent contrasts were used for comparisons between shapes. There were no significant differences in shape variation between all the specimens based on the PCA results. However, CVA results showed shape variations between specimens taken from the four areas of Peninsular Malaysia, especially with higher magnitudes of Mahalanobis distances between the east and west coast areas, including between East-Central and East-North, but lower magnitudes were detected between the West-Central and West-North.

Scyphozoan jellyfish outbreak events are drawing increasing attentions during the past decade. Elemental compositions of statoliths are helpful to understand jellyfish life history and blooming mechanisms, but very rare endeavor has been focused on the Scyphozoan class. In this work, we explored the feasibility of element analysis of Aurelia aurita (a representative Scyphozoan jellyfish outbreak species in China) which may be used as proxies of environment parameters during jellyfish living and moving. Statolith crystals of Aurelia aurita were found to be a gathering of hexahedron type trigonal needle with size of 10−50 μm long, and 5−10 μm in diameter. By using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) downhole profiling method, elements such as Ca, Sr, Mg, Na and P were found to be above the limit of detection and limit of quantification. The epidermis of statocyst could significantly impact the element analyses, so the real statolith element signal section needs to be selected based on elements and Ca profiles together with care. By laser ablated a signal spot repeatedly, the analytical uncertainty was about 3%−4% for Sr/Ca content ratio and Mg/Ca content ratio, but above 10% for other element/Ca content ratios (n=3). Based on the analysis of statolith from temperature-control cultured jellyfish, Sr/Ca content ratios among different statoliths of the same jellyfish were about 6% (n=14), demonstrating biological processes/vital effects causing small variations compared with analytical uncertainties. Therefore, Sr/Ca content ratios may be used as a potential proxy to reveal the living environment variations the Scyphozoan jellyfish has experienced, such as temperature history, which is helpful to understand jellyfish bloom mechanisms.