Wouldn’t you think that an animal that lives within a poisonous environment (such as Man-of-War fish living within the tentacles of the Portuguese Man-o-War) would develop a better system to avoid being stung than being “agile and extra bendy?”
PORTUGUESE MAN OF WAR & MAN OF WAR FISH
Physalia physalis & Nomeus gronovii
© Seth Patterson
The Portuguese Man o’ War is not one animal, but is actually comprised of colonies of invertebrate, jelly-like marine animals of the family: Physaliidae glomming together. These pelagic hydroids (or hydrozoans) colonize and are infamous for their very painful, powerful sting.
It would seem wise for marine life to steer clear of the Man of War’s stinging tentacles however it shares an interdependence with a variety of transient marine fish, including shepherd fish, clownfish, yellow jack and one fish specialized to live within its tentacles—the man of war fish.
The man-of-war fish is generally found in open sea or close to the Portuguese man of war, after which it is named. It is found in all tropical and subtropical oceans.
The fish is striped with blackish-blue blemishes covering its body, and the caudal fin is extremely forked. It grows to a length is up to 15.5 inches (39 cm).
As unlikely as it seems, this fish, rather than using mucus (like the clownfish) to prevent stings, appears to uses highly agile swimming to physically avoid tentacles. The fish has a very high number of vertebrate (41), which adds to its agility and uses its pectoral fins for swimming — a feature common in fish who specialize in maneuvering in tight spaces. It also has a complex skin design containing at least one antigen to the man-of-war’s stinging toxin. The fish seems to be ten times more resistant to the toxin than other fish.
Fact Source: http://en.wikipedia.org/wiki/Man-of-war_fish
Portuguese Man of War
Flower Hat Jellyfish