''Malo maxima'' is a small, and extremely dangerous

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 ...

that is known to cause

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 ...

. It is one of the four species of '' Malo'', along with ''Malo bella'', '' Malo filipina'', and '' Malo kingi''. The ''Malo maxima'' was first described in 2005 by Lisa-ann Gershwin, who also described the Malo bella and ''Malo kingi'' jellyfish along with over 200 other species of jellyfish. ''Malo maxima'' differs from other species of jellyfish in many ways but the most confusing one is that they swim more like fish than jellyfish, however the reason for this is still unknown.

Phylogeny

The ''Malo maxima'' has a tall, narrow, robust body with a flattened apex and measures to about 5 cm. Even though it is very small, ''Malo maxima'' is the largest member of its genus. The individuals are also translucent, making them very difficult for the human eye to see easily. Research from the scientific paper “Early Life History and Metamorphosis in ''Malo maxima''” showed that the metamorphosis of ''Malo maxima'' from a sessile (immobile) polyp into a free-swimming medusa took 111 days following fertilization.

Distribution

Irukandji Jellyfish can be found in oceans all around the world, however ''Malo maxima'' can only be found in the tropical

western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

n waters, specifically the Broome region. It is believed that ''Malo maxima'' have specific habitat preferences considering they tend to live in similar regions. However, there is currently no solid evidence to back up this theory because scientists have still not identified their polyp states. The Irukandji Jellyfish does not tend to be close to shore but every now and then they wander into a close proximity to shore. This tends to be the only time humans come into contact with Irukandji Jellyfish unless it is bloom season. The sign that Irukandji Jellyfish are in the area includes sea lice felt in the water and clusters of

salp A salp (: salps, also known colloquially as “sea grape”) or salpa (: salpae or salpas) is a barrel-shaped, Plankton, planktonic tunicate in the family Salpidae. The salp moves by contracting its gelatinous body in order to pump water thro ...

Irukandji-jellyfish-queensland-australia

The sting and venom

The sting of all Irukandji Jellyfish is believed to cause Irukandji Syndrome and can be potentially fatal, however the sting of the ''Malo maxima'' is the most dangerous of the Malo species. Only two types of species have the venom to cause Irukandji syndrome, the Irukandji Jellyfish and the Box Jelly. The Box Jelly is extremely more venomous than the Irukandji Jellyfish. Stings from a Box Jelly are much more fatal than those of an Irukandji Jellyfish, however that does not make Irukandji stings any less dangerous and painful. Irukandji syndrome can cause sweating, anxiety, muscle spasm, severe

hypertension Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms i ...

and potentially late

hypotension Hypotension, also known as low blood pressure, is a cardiovascular condition characterized by abnormally reduced blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood and is ...

and cardiac failure. The sting site has minimal local reaction and does not take effect right away and becomes worse as time goes on. Scientists have just recently figured out how the venom of the ''Malo maxima'' affects the heart. The venom causes a concentration-dependent

inotropic An inotrope or inotropic is a drug or any substance that alters the force or energy of muscular contractions. Negatively inotropic agents weaken the force of muscular contractions. Positively inotropic agents increase the strength of muscular co ...

responses in the left atria of the heart, however it has no effect on the right atria. It appears that the venom does not activate the

parasympathetic nervous system The parasympathetic nervous system (PSNS) is one of the three divisions of the autonomic nervous system, the others being the sympathetic nervous system and the enteric nervous system. The autonomic nervous system is responsible for regulat ...

, but the

sympathetic nervous system The sympathetic nervous system (SNS or SANS, sympathetic autonomic nervous system, to differentiate it from the somatic nervous system) is one of the three divisions of the autonomic nervous system, the others being the parasympathetic nervous sy ...

. The venom also stimulates the sensory nerve CGRP to release in only the left atria and the resistance arteries. The most effective therapy for Irukandji syndrome seems to be an intravenous infusion of

magnesium Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 ...

Blooms

Australia experiences extreme jellyfish blooms, specifically Irukandji Jellyfish blooms. The Irukandji Jellyfish blooms include ''Malo maxima'' as well as the other types of Irukandji. Human activity such as catching fish and pollution are making them a more common occurrence. These blooms take a toll on the ecosystems around them. They also make it difficult for ships to get through and make the water extremely dangerous for divers.

References

* Straehler-Pohl, I., Carrette, T., Sleeman, J., Seymour, J., Underwood, A., Carrette, T., & Seymour, J. (2018). ''Early life history and metamorphosis in Malo maxima Gershwin'', 2005 (Carukiidae, Cubozoa, Cnidaria). Plankton and Benthos Research, 13(4), 143–153.

External links

{{Taxonbar, from=Q2140482 Cnidarians of Australia Carukiidae Animals described in 2005