What’s the most venomous marine animal?

photo of box jellyfish

Carybdea branchi, pictured right here, is a relative of the Australian field jellyfish (Chironex fleckeri), which is taken into account probably the most venomous marine animal. (Picture courtesy of Brent Viljoen)


They might not look harmful, however the sting from a field jellyfish might be sufficient to ship you to Davy Jones’s locker-a watery grave, that’s.

Field jellyfish, named for his or her physique form, have tentacles lined in organic booby traps referred to as nematocysts – tiny darts loaded with poison. Folks and animals unlucky sufficient to be injected with this poison could expertise paralysis, cardiac arrest, and even dying, all inside a couple of minutes of being stung. However don’t select the mountains over the ocean simply but. Of the 50 or so species of field jellyfish, additionally known as sea wasps, only some have venom that may be deadly to people.

Whereas field jellyfish are present in heat coastal waters world wide, the deadly varieties are discovered primarily within the Indo-Pacific area and northern Australia. This consists of the Australian field jellyfish (Chironex fleckeri), thought of probably the most venomous marine animal. Chironex fleckeri is the biggest of the field jellyfish, with physique sizes reaching as much as one foot in diameter and thick, bootlace-like tentacles as much as 10 ft lengthy.

Field jellyfish have traits that set them other than different jellyfish. Most notably, field jellyfish can swim—at most speeds approaching 4 knots—whereas most species of jellyfish float wherever the present takes them, with little management over their path. Field jellyfish may also see. They’ve clusters of eyes on both sides of the field. A few of these eyes are surprisingly subtle, with a lens and cornea, an iris that may contract in brilliant gentle, and a retina.

Their pace and imaginative and prescient leads some researchers to imagine that field jellyfish actively hunt their prey, primarily shrimp and small fish.

What’s a Portuguese Man o’ Conflict?

The Portuguese man o’ war is recognized by its balloon-like float.

The Portuguese man o’ battle is acknowledged by its balloon-like float, which can be blue, violet, or pink and rises as much as six inches above the water line. Picture credit score: Elizabeth Condon, Nationwide Science Basis

The Portuguese man o’ battle, (Physalia physalis) is typically referred to as a jellyfish, however is definitely a species of siphonophore, a bunch of animals which can be intently associated to jellyfish. A siphonophore is uncommon in that it’s comprised of a colony of specialised, genetically similar people referred to as zooids — clones — with varied types and capabilities, all working collectively as one. Every of the 4 specialised elements of a person o’ battle is chargeable for a particular job, corresponding to floating, capturing prey, feeding, and copy. Discovered largely in tropical and subtropical seas, males o’ battle are propelled by winds and ocean currents alone, and generally float in legions of 1,000 or extra!

Resembling an 18th-century Portuguese warship below full sail, the person o’ battle is acknowledged by its balloon-like float, which can be blue, violet, or pink and rises as much as six inches above the waterline. Lurking under the float are lengthy strands of tentacles and polyps that develop to a mean of 10 meters (about 30 toes) and will prolong by as a lot as 30 meters (about 100 toes). The tentacles include stinging nematocysts, microscopic capsules loaded with coiled, barbed tubes that ship venom able to paralyzing and killing small fish and crustaceans. Whereas the person o’ battle’s sting isn’t lethal to individuals, it packs a painful punch and causes welts on uncovered pores and skin.

Beachcombers be warned: The stalwart man o’ battle should sting you even weeks after having washed ashore.