Black Sea nettle

The Black Sea nettle (Chrysaora achlyos) or sometimes known as the Black jellyfish is known for its dark coloration. This species of jellyfish is found in the Pacific Ocean. There have been reports or sighting of the black jellyfish as for north as British Columbia but its range is mostly thought to be from the north in Monterey Bay, to the southern shores of Baja California and Mexico.

The Black Sea nettle is quite large. The bell of the jellyfish can measure up to 3 feet in size while the oral arms can extend up to 20 feet in length. Despite its size and nearness to Pacific coastal cities, the black jellyfish was identified and scientifically characterized as a different species in 1997. The scientific contrast of the black jellyfish is that it is the largest invertebrate that has been discovered in the twentieth century.

Sightings of the Black Sea nettle are rare although when they are seen they are usually seen in vast groups. In 1989 and 1999 great sightings of the black jellyfish occurred in the Baja California and southern California in the surface waters off of the coasts. During the time of these sightings the red tide incident simultaneously occurred, which contained zooplankton that the black jellyfish feed on.

The Sea nettle is symmetrical, carnivorous and marine. The mouth of a sea nettle is at the center of one end of the bell which opens to a gastrovascular cavity used for digestion. To capture food the Black Sea nettle uses the tentacles around its mouth. Sea nettles do not have respiratory or excretory organs. The black jellyfish are carnivorous. These jellyfish feed on other jellyfish and zooplankton. Sea nettles obtain and immobilize their prey by stinging with their tentacles. From there the prey is sent to the gastrovascular cavity and digested.

Every sea nettle tentacle has thousands of microscopic nematocysts which are coated on, and every separate nematocyst has a “trigger” (cnidocil) that is set with a capsule that contains a coiled stinging filament. Once touched or contacted with the cnidocil immediately begins a process which releases venom-coated filament from its capsule and into its target. This injects toxins that are capable of killing small prey or stunning predators. For humans, the stinging sensation will be painful but mostly likely non-lethal and can last for forty minutes.

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