From OpenwaterpediaBlue Jelly (Catostylus mosaicus) is a species of jellyfish in the Rhizostomeae order. It is characterized by a lack of tentacles at the margin of the jellyfish's body. Instead, it has about 8 oral arms. These oral arms become fused with the body of the jellyfish near the centre of its body. What is fascinating about the oral arms of the blue blubber is that they have minute mouths at the end of the oral arms that themselves transport food to the stomach.
The blue blubber is a nuisance off the coast of Australia. The number of blue blubbers on the coasts of Australia has increased tremendously over the last few years because of the absence of the predators, caused by over-fishing. These large swarms of blue blubbers are clogging the water intakes on ships and power stations, and are also ruining fishing nets and poisoning the catch.
This species is easily distinguished by its oral arms and the presence of internal cross-like design. These are actually the gonads of the blue blubber that are visible through its gelatinous body, which is semi-transparent. Although, blue blubbers usually have eight oral arms, a number of specimens have been found with just three or four oral arms. Also, the oral arms of the blue blubber have a certain three-pronged shape that makes them easy to identify.
Blue blubbers are amongst those species of jellyfish that maintain a symbiotic relationship with unicellular algae. These algae are photosynthetic in nature and they reside in the body of the blue blubber. These algae use sunlight to produce energy and carbon rich nutrition. The alga also provides this nutrition to its carrier blue blubber. Thus, a large part of the blue blubbers nutrition comes from the food matter provided by the algae.
However, this implies that the blue blubber needs to be close the surface of the water to get maximum sunlight for this process of photosynthesis. However, the nutrition provided by the algae is not sufficient for the blue blubber. It also needs to hunt and feed itself. After sundown, the blue blubber descends to lower parts of the water to feed on microscopic food. The size of its miniscule mouths at the end of the oral arms restrict intake of food larger than minute planktons and zooplanktons. However, the blue blubber is able to derive enough nourishment between the two sources of food.
The blue blubber uses its oral arms to capture its food. Its oral arms are lined with numerous nematocysts that contain venomous stings. When blue blubbers come in contact with a prey, they inject their venom into the prey in order to kill or paralyze it. Once the prey is immobilized, the blue blubber eats it with its tiny mouths. The blue blubber uses the same mechanism to defend itself from predatory animals. In the case of humans, the toxins in the venom of blue blubbers does not cause any harm. Very sensitive individuals may develop an itchy rash or have an allergic reaction.