Earl James S. Arlos, Janelle Margaret H. Sentina, Leo Emmanuel O. Sombiro (March 2014)
Philippine Science High School Western Visayas Campus – Department of Science and Technology (DOST-PSHS WVC), Brgy. Bito-on, Jaro, Iloilo City 5000, Philippines
ABSTRACT
Jellyfish blooms interfere with fisheries and tourism. Swimmers are often caught by surprise when they get stung. The severity of stings varies from redness to death. The effect of the structural properties of the nematocysts in the stinging process is not fully understood. The main objective of this study is to establish a possible relation between the nematocyst types of different jellyfish species and their dermatological effects. The jellyfish species gathered are Aurelia aurita, Cassiopeia xamachana, and Rhizostome sp. Jellyfish tentacles were observed from using a light microscope and scanning electron microscope. Identification of the nematocysts was done by comparing the morphology of a cnidome with given diagrams and descriptions Motionless jellyfish tentacles were placed in contact with a standardized area of pig skin approximately 2 in x 2 in for more than 15 seconds. the degree of inflammation on the pig skin were observed at the initial four minutes after the tentacle exposure, and then at thirty minute intervals for four hours. Dermatological effects were classified as no skin manifestation, slight color changes, pronounced color changes, structural changes or vesicles. All observations were done visually and descriptively. All samples of pig skin did not exhibit any dermatological effect after exposure to the tentacles of the three different jellyfish species. LM observations of the tentacles did not show any diagnostic features. Isorhizas, a type of nematocyst without a well-defined shaft, were identified in the Rhizostome sp. under SEM. The structure of the nematocysts could possibly contribute to the severity of the sting.