Mangrove Jellyfish

Mangrove jelly fish (Cassiopea xamachana) is so called because it is mostly found in the roots of mangroves in the southern Gulf of Mexico, Caribbean, and other tropical waters. They are also called the Upside Down jellyfish because they tend to settle upside down in muddy and shallow waters. On first sight, they do not really resemble a jellyfish, instead looking more like a sea anemone, or a bluish green flower on the waterbed. However, this appearance also provides the jellyfish with very effective camouflage and protects it from likely predators.

The reason a mangrove jellyfish is always upside down and lives in shallow waters which are saturated with sunlight, is to allow give these algae, which reside in its body, access to ample sunlight, so that photosynthesis of food becomes possible.

Jellyfish : A clever hunter for a creature with no brain

 Although they look harmless, jellyfish are remarkably efficient predators, able to stun and kill their prey with stinging cells (nematocysts). Each cell contains a tiny harpoon which, when triggered by touch or movement, shoots into the prey and delivers a debilitating toxin.
The potency of this toxin varies among jellyfish, causing reactions in humans ranging from mild rashes to death. Some, like the sea nettle, are simply an annoyance to those who are stung, while others, like the box jellyfish (see A God of Love—Creator of a Killer Jellyfish?) are very dangerous and sometimes cause death.

Of course, jellyfish don’t set out to hurt humans—their preferred food ranges from microscopic animals and fish larvae to other jellyfish. Usually people are stung when jellyfish are carried close to shore, where swimmers inadvertently brush against them.

Floating along in the water, jellyfish can be both predator and prey. Because most jellyfish are almost transparent, they are able to camouflage themselves quite well against their watery background, which is important because, while they can use jet propulsion to move about in the water, they are also at the mercy of the current, and in the open sea, there is nowhere to hide.