''Carukia barnesi'' is an extremely

venom Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

ous

box jellyfish Box jellyfish (class Cubozoa) are cnidarian invertebrates distinguished by their box-like (i.e., cube-shaped) body. Some species of box jellyfish produce potent venom delivered by contact with their tentacles. Stings from some species, including ' ...

found near

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. Stings can result in

Irukandji syndrome Irukandji syndrome is a condition that results from envenomation by certain box jellyfish. In rare instances the sting may result in cardiac arrest and death. The most common jellyfish involved is the '' Carukia barnesi'', a species of Irukand ...

, and this species is commonly known as Irukandji jellyfish, although this name does not distinguish it from other

Irukandji jellyfish The Irukandji jellyfish ( ) are any of several similar, extremely venomous species of rare box jellyfish. With a very small adult size of about a cubic centimetre (1 cm3 or 0.061 in3), they are both one of the smallest and one of the ...

such as '' Malo kingi''. A mature ''C. barnesi's'' bell is only in height. It has four contractile

tentacles In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...

, one extending from each bottom "corner" of its bell, ranging in length from . The species was discovered by Jack Barnes of

Cairns Cairns (; ) is a city in the Cairns Region, Queensland, Australia, on the tropical north east coast of Far North Queensland. In the , Cairns had a population of 153,181 people. The city was founded in 1876 and named after William Cairns, Sir W ...

, Australia. While on an exploration mission aimed at determining the reason for

, Barnes allowed himself, a lifeguard, and his 9-year-old son to be stung by the jellyfish. ''Carukia barnesi'' is a soft-bodied marine organism. This species falls within the

Medusozoa Medusozoa is a clade in the phylum Cnidaria, and is often considered a subphylum. It includes the classes Hydrozoa, Scyphozoa, Staurozoa and Box jellyfish, Cubozoa, and possibly the parasitic Polypodium (animal), Polypodiozoa. Medusozoans are dis ...

subphylum In zoological nomenclature, a subphylum is a taxonomic rank below the rank of phylum. The taxonomic rank of " subdivision" in fungi and plant taxonomy is equivalent to "subphylum" in zoological taxonomy. Some plant taxonomists have also used th ...

and the Cubozoa class. It is a type of "

" that is known for producing potent venom and is known for inflicting the Irukandji syndrome.

Threat to humans

The Irukandji syndrome was first discovered after a group of swimmers were stung in the open water near

North Queensland North Queensland or the Northern Region is the northern part of the Australian state of Queensland that lies just south of Far North Queensland. Queensland is a massive state, larger than many countries, and its Tropical North Queensland, trop ...

, Australia. Victims of the sting reported severe symptoms of muscle aches, back pain, nausea, headaches, chest and abdominal pains, sweating, high blood pressure and difficulty breathing. Intravenous administration of

morphine Morphine, formerly also called morphia, is an opiate that is found naturally in opium, a dark brown resin produced by drying the latex of opium poppies (''Papaver somniferum''). It is mainly used as an analgesic (pain medication). There are ...

hydromorphone Hydromorphone, also known as dihydromorphinone, and sold under the brand name Dilaudid among others, is a morphinan opioid used to treat moderate to severe pain. Typically, long-term use is only recommended for pain due to cancer. It may b ...

fentanyl Fentanyl is a highly potent synthetic piperidine opioid primarily used as an analgesic (pain medication). It is 30 to 50 times more Potency (pharmacology), potent than heroin and 50 to 100 times more potent than morphine. Its primary Medici ...

is used to treat patients with this syndrome.

Pethidine Pethidine, also known as meperidine and sold under the brand name Demerol among others, is a fully synthetic opioid pain medication of the phenylpiperidine class. Synthesized in 1938 as a potential anticholinergic agent by the German chemist Ot ...

is avoided due to the toxic metabolite

norpethidine Norpethidine (normeperidine, pethidine intermediate B) is a 4-phenylpiperidine derivative that is both a precursor to, and the toxic metabolite of, pethidine (meperidine). It is scheduled by UN Single Convention on Narcotic Drugs. It is a Sch ...

because of the high amounts needed to achieve pain relief. Most reported incidents have been localized to Australia during the warm summer season. Due to the small size of ''C. barnesi'' (approximately 20 mm in diameter and 25 mm in depth of the bell), they often go undetected in the open water.

Description

The structure of ''C. barnesi'' follows that of a

- it has a square-shaped bell structure and long tentacles that extend out of the four corners of its base. The tentacles house the nematocysts which are stinging cells.Type I nematocysts (homotrichous microbasic rhopaloids) and Type II nematocysts (homotrichous haplonemes) are both found on the tentacles and bells of the species.

Muscle cell A muscle cell, also known as a myocyte, is a mature contractile Cell (biology), cell in the muscle of an animal. In humans and other vertebrates there are three types: skeletal muscle, skeletal, smooth muscle, smooth, and Cardiac muscle, cardiac ...

s in the tentacles bring food to its mouth, where it then enters a gastric cavity and is digested. The nematocysts are capable of producing venom that changes composition as ''C. barnesi'' matures to adulthood and prey changes from invertebrates (

zooplankton Zooplankton are the heterotrophic component of the planktonic community (the " zoo-" prefix comes from ), having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequent ...

and

crustaceans Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of Arthropod, arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquat ...

) to vertebrates.

Life cycle

Cubozoans follow a life cycle that alternates between young benthic sessile polyps and adult motile pelagic

medusae Jellyfish, also known as sea jellies or simply jellies, are the medusa-phase of certain gelatinous members of the subphylum Medusozoa, which is a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals, althoug ...

. The cycle begins with a planula larvae. This planula will continue to swim until it finds a substrate that it can use as support. Once the planula attaches to a substrate like a

coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in group ...

or rock, the organism will morph into a polyp. This polyp can remain asexual for extended periods of time. Eventually, the polyp will begin to clone and form a polyp colony. As it continues to acquire nutrients, the colony will develop into an adult medusa.

References

External links

{{Taxonbar, from=Q135000 Carukiidae Cnidarians of Australia Animals described in 1967