Carybdeida

Carybdeida is an order of box jellyfish within the class Cubozoa, phylum Cnidaria. It comprises several families, including Carybdeidae, and contains genera such as Carybdea. Members of this order are distinguished from the related Chirodropida by the arrangement of their tentacles: Carybdeida medusae typically bear a single tentacle (or one per corner) at each corner of the cube-shaped bell, whereas Chirodropida have multiple tentacles per corner. The bells are usually transparent and square or cube-like, and the animals possess well-developed sensory organs.

Morphology and biology: Like other cubozoans, Carybdeida have complex eyes formed by rhopalia, which give them advanced light detection and, in some species, image-forming capabilities. They are heterotrophic predators that use their tentacles to capture small prey such as crustaceans and fish. The life cycle follows the cubozoan pattern, with a planula larva developing into a sessile polyp (scyphistoma) that can reproduce asexually to produce free-swimming medusae (ephyrae), which then grow into adults.

Distribution and ecology: Carybdeida jellyfish are found in tropical and subtropical seas worldwide, frequently inhabiting coastal and nearshore environments, including when estuarine and reef-associated habitats. They are active swimmers and rely on their mobility and sensory capabilities to hunt.

Venom and human interactions: Members of this order produce potent venom, and stings can cause severe pain and potentially serious cardiovascular or dermatological effects. First aid typically includes safe removal of tentacles with tweezers, rinsing with vinegar to inactivate undischarged nematocysts, and seeking prompt medical care. In some regions, antivenoms or region-specific treatments are used for cubozoan envenomation. The group is of medical interest due to the potency of its venom and its presence in popular tourist areas.