Field Guide to Venomous and Medically Important Invertebrates ...

Carukia barnesi is a small box jellyfish widely distributed in the southern Pacific and it is
commonly known in Australia as Irukandji, the name of an Aboriginal tribe. This species is
commonly found in both open and coastal waters. The bell of this diminutive species is only
about 0.78 inch (20 mm) in diameter and there are four long tentacles. The clinical presentation
of their stings is characteristic and is known as the Irukandji syndrome. An initial stinging
sensation that diminishes after a few minutes may remain unnoticed by the victim but on other
occasions may be quite severe. The subsequent development of local pain in the affected limb is
also variable. The area around the sting site becomes reddened with small lesions appearing like
gooseflesh. There may be an associated reaction where the skin is dry initially followed by
excessive localized sweating. Systemic symptoms usually commence about 30-40 min after the
initial sting, but they may last from 4-96 hours although around 12 hours is more typical.
Widespread pain is predominant, especially in the abdomen, large muscle groups in the back,
and joints. Headache is often severe. Other symptoms may develop including high blood
pressure, rapid and irregular heartbeat, sweating, agitation, nausea and vomiting. In severe
cases, the symptoms may progress to low blood pressure, pulmonary edema, shock and heart
failure. Heart attacks may occur, even in the absence of recognized risk factors. Although no
deaths have been conclusively attributed to this jellyfish, Irukandji syndrome can be severe and it
is quite possible deaths have occurred historically. Other box jellyfish belonging to the same
family as Carukia also can inflict envenomations with similar symptoms. They include several
species box jellyfish in the genus Carybdea that are widely distributed in the southern Pacific
Ocean.
Figure 233. Irukandji (Carukia barnesi). Photo: Lisa Ann Gershwin.
Figure 234. Box jellyfish (Carybdea sp.). Photo: Lisa Ann Gershwin.