Nematocyst Types and Characteristics in the Tentacles of Gershwinia thailandensis and Morbakka sp. (Cubozoa: Carybdeida) from the Gulf of Thailand

Abstract

This study investigated the nematocyst types found in the tentacles of box jellyfish Gershwinia thailandensis and Morbakka sp. in Thai waters, providing detailed taxonomic insights into these toxic stinging cells. Three nematocyst types were identified in both species: club-shaped microbasic p-mastigophores (Type 4), oval isorhizas, and oval microbasic p-rhopaloids. While the sizes of nematocyst capsules varied between species, the spination pattern of discharge tubules was consistent. These differences in nematocyst types, population densities, and morphologies may indicate evolutionary adaptations and functional specialization. Understanding these distinctions could aid in developing species-specific envenomation treatments and deepen our knowledge of the ecological and toxicological roles of these nematocysts. Further research on the molecular composition and venom release mechanisms will offer valuable biological insights.