Question

Portuguese man of war is
A. Obelia
B. Physalia
C. Aurelia
D. Branchiostoma
E. Platypus

Answer 1

Hint: The Portuguese man of war is a hydrozoan marine predatory organism. It is found in the Indian ocean and the Atlantic ocean. It has numerous venoms producing microscopic structures that kill fish and even humans.

Complete answer:
The Portuguese man of war is a common name for Physalia physalis. It is an aquatic hydrozoan found in the Indian ocean and the Atlantic ocean. It resembles jelly-fish in its shape but is very different from it. Physalia are siphonophores which is a class of Hydrozoans and is a colonial organism. It is made of many specialized parts called zooids that are genetically distinct. These zooids cannot survive independently and thus are attached to each other. Each individual zooid works together to function as an individual Physalia.
Portugues man of war is the only known species in the genus Physalia. The characteristic feature of these organisms is the presence of microscopic structures called nematocysts. Nematocysts produce a venomous secretion that enters the prey’s body by the sting and paralyzes it till death. This venomous secretion is also sometimes known to harm humans. It is a very painful venom that directly kills the fish. The nematocysts lie on the tentacle of Physalia and tentacles sting the prey’s body. In humans, the sting is characterized by a whip-like red welt that lasts for two to three days. The venom reaches the lymph nodes and mimics an allergic reaction which causes swelling of the larynx and consequently airway blockage. Cardiac distress, fever, shocks, and inability to breathe are common symptoms of the sting from the Portuguese man of war.
So, from the above discussion, we can conclude that the right answer is option B.

Note: Stings from Portuguese man of war can cause long, thin exposed wounds. Acetic acid or vinegar is believed to deactivate the venom. Ammonia soak is also used to treat the sting as it provides pain relief and removes remaining nematocysts.