Box jellyfish
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Box jellyfish, also known as sea wasps, are creatures found in Australia and the Philippines that can be extremely deadly, with venom in their tentacles. They are of the class Cubozoa and are similar to 'regular' jellyfish, Scyphozoa. Cubozoa are square or rectangular shaped when viewed from above.
In summer, it becomes impossible for people to swim in northern Queensland since these jellyfish, which can kill, become very numerous in the warmer seasons.
The largest of the box jellyfish, Chironex fleckeri has venom which is very different from that of other kinds of jellyfish. It has been conjectured that the extremely deadly venom enables them to catch their prey of fish and other small invertebrates. The younger box jellyfish's venom is different since they do not need to feed on large prey.
Australian researchers have used ultrasonic tagging to learn that these creatures sleep on the ocean floor between 3pm and dawn. It is believed that they sleep to conserve energy and to avoid predators.
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Vision
There has been some theory in that these jellyfish actively hunt their prey—for effective hunting they move extremely fast (moving at speeds up to 3-3 1/2 knots (1.5 to 1.8 m/s)), and have an active visual system of 48 eyes located on the center of each side of the cubozoan's bell.
Within each set of eyes are two complex lens eyes. The lenses on these eyes have been analyzed and could form distortion free images. Despite the perfection of the lenses, the retinas of the eyes lie closer to the lens than the optimum focal distance resulting in a blurred image. One of these eyes in each set has an iris that contracts in bright light. Four of the eyes can only make out simple light levels.
It is not currently known how this visual information is processed by Cubozoa, as they lack a central nervous system.
Classification
There are two main groups of Cubozoa, Chirodropidae and Carybdeidae containing 20 species between them. A phylogenic analysis of their relationships is yet to be published.
- Taxon Chirodropidae
- Taxon Carybdeidae
Medical Advice
It has been anecdotally reported that pantyhose is worn by Australian lifeguards to prevent stings.
If swimming at a beach where box jellyfish are known to be present, a bottle of vinegar is an extremely useful addition to the first aid kit. For some as yet unknown reason, acetic acid, found in vinegar, disables the box jellyfish's nematocysts, or stinging cells. If stung, bathe the affected area with liberal amounts of vinegar, but immediately seek medical attention also. Vinegar has helped save dozens of lives on Australian beaches.
Warning: this advice is only intended to be a stopgap until the patient can be taken to a doctor. This advice is not intended to be a substitute for advice from a qualified doctor.
References
External link
- Cubozoa classification (http://www.ucmp.berkeley.edu/cnidaria/cubozoasy.html)