# Malo (jellyfish)

Malo is one of a genus of box jellies in the family Carybdeida in the Phylum Cnidaria. It has four known species, three of which were described by the Australian marine biologist Lisa-Ann Gershwin. The genus was discovered in 2005. Many of the species are known for their paralytic and deadly affect. Many species in the Malo genus are very small and hard to capture and study. Many species of Malo have been captured on the Western and Eastern cost of Australia. Malo appear to be solidarity jellies.

## Etymology

The name Malo is derived by the first two letters of the name of Mark Longhurst, who survived a severe sting by a jellyfish apparently from the genus shortly before the publication of its discovery. The author, Gershwin, also noted the "interesting coincidence that the word “malo” is Spanish for “bad”, as this species is presumed to be capable of lethal envenomation. Gender masculine."

## Taxonomy

* Family: Carukiidae
* Genus: Malo
** Malo bella Gershwin, 2014
** Malo filipina Bentlage & Lewis, 2012
** Malo kingi Gershwin, 2007
** Malo maxima Gershwin, 2005

## Irukandji Syndrome

The "Irukandji" jellyfish are known for their deadly and fast acting toxins. Irukandji stings are the highest occupational safety hazard for Marine industries in Australia and the Indo-Pacific Ocean. The known "Irukandji" jellies include species: Malo maxima, Malo kingi, Carukia shinju, Carybdea xaymacana, Alatina mordens, Gerongia rikinae, and Morbakka fenneri. Malo jellies release venom from the tips of the nematocyst. The venom from a single sting can take 20–60 minutes to induce "Irukandji syndrome". When stung the pain is mild with minor inflammation at the sting location. The symptoms progressively get more severe as time goes. Symptoms include: muscle cramps, vomiting, sweating, agitation, vasoconstriction, prostration, hypertension, and severe envenomation, and acute heart failure. The toxins induce modulation of neuronal sodium channels leading to massive release of endogenous catecholamine (dopamine, epinephrine, and norepinephrine) and stress-induced cardiomyopathy. Causing membrane leakage of troponin, cerebral edema, priapism, and death in some cases.

### Treatment

The only uniform treatment for Irukandji Syndrome is Nitroglycerin; recommended by the Queensland Government Irukandji Taskforce. Nitroglycerin is given to the patient for hypertension associated with the sting. Nitroglycerin is a vasodilator to counteract the vasoconstriction from the venom. Nitroglycerin delays and manages the onset of symptoms by slowing down the overdrive of the sympathetic system. The most common Non-uniform treatment consist of heat packs and domestic vinegar. For alleviating localized pain heat applications have shown more promising than ice packs. Domestic vinegar has shown to inactivate undischarged nematocysts. For clinical treatment pain is managed with various analgesic and medication to prevent cardiac failure in severe cases.

## Geographic range

Species such as Malo Maxima and Malo Kingi have been found in the Northern and the Western territories of Australia. Malo Filipina and Malo Bella have been found in the Indo-Pacific Ocean waters, mostly off the coast of the Philippines. Reports of other possible locations of the Malo genus of Jellies have been in Hawaii, Florida, Papua New Guinea, French West Indies, Bon Air, and Caribbean. There is an undescribed species of Malo that is indigenous only to the island of Exmouth. One valuable tool to help learn more about the geographic range of harder species to study is eDNA. Edna (environmental DNA) is extra-organismal genetic material that is shed by the organism. The technique uses species-specific DNA identifiers in collected samples to gain insight on rare and mysterious animals.

## Anatomy and morphology

The Malo genus of jellies are incredibly small and translucent making identification hard. Malo are in the family Carukiidae and are distinguishable from other box jellies by their size and location of nematocysts. Malo also have a lack of cirri clumps (gastric phacellae) in the stomach. The Malo genus of jellyfish has a cubic medusa bell with a tentacle at each corner. The maximum bell height is 2–5 cm with a taller flat apex. The tentacles are round in cross-section and are very fine. The medusa bell is tall and narrow with an unbranched muscular basa at the corners. The total of four corners of the bell are referred to as pedalium. The pedalial shape is narrow with a knee-shaped canal bend. The Exumbrellar warts are purple freckles.
Malo contain a frown shaped rhopalial niche openings where they are undivided on the upper and lower covering. There are 2 median eyes that are lensed per rhopalium and lack laterals. Laterals are thought to aid in peripheral filtering. It is unknown if Malo has less visual ability or have evolved to no longer need lateral eyes. Malo jellies have rhopaliar horns above the rhopalial niches that are nonvenomous. The horns are broad curved, and short with their function unknown.
The Malo genus are box jellies and are extremely toxic. The nematocysts that release the toxins are segmented on the pedalium. The tentacular nematocysts are often adhered to the skin after they are expelled. The species Malo kingi has mammillation which are a collection of stinging cells on the apex and walls of the bell.

## Further research and pharmacology

With climate change there have been an increase in blooms of Irukandji jellies. Further research is being conducted on an anti-venom and medical research. As stings have become more pervasive on the coast of Australia there has been an increase in funding for research. The venom from the species Malo maxima have been successfully studied in the cardiovascular tissue of rats. The venom puts the sympathetic and nervous system into overdrive. Stimulating the sensory nerve CGRP into the left atria and resistance arteries. Malo maxima have provided evidence of the biochemical effects of Irukandji venom.