Nemo's in the Gables

This large cinnamon polyp (Palythoa grandis), is feasting on a cleaner shrimp. Somehow, this unlucky shrimp managed to lightly touch the surface of the polyp but it was just enough for millions of nematocysts to harpoon their way into the soft tissues of the cleaner shrimp and hold it tightly. Cinnamon polyps are the larger polyped cousins of members of the order zoantharia, the toxic polyps.  A recent study shows, however, that Palythoa grandis is more toxic than the zoanthids. The name palytoxin comes from the order Palythoa. 

In the figure below, obtained from itis.gov, are results from a recent study on the toxicity of the Palythoa grandis  as compared to species of zoanthid and palythoa species as a whole.  As you can see, the results are remarkable. Palythoa grandis  packs more palytoxin than the famous zoanthids.  Click here to read about one reefkeepers personal experience with palytoxin.

Certain corals cannot be placed in close proximity to each other. Some anemones are likely to kill a small fish in your aquarium. If you have ever wondered why, organs called cnidae are to blame. The animals in the phylum cnidaria (nahy-dair-ee-uh-n) are divided into the class Anthozoa (corals and sea anemones) and Medusae (jellies and hydras). They are all defined by their cnidocytes, the primary method for capturing prey. These cnidae function as microscopic weapons which are expelled by the cells in which they are contained and attach to prey. Cnidae can function as harpoons which penetrate and stick, known as nematocysts. They can also function as as a lasso and have a grappling effect which wraps around a projection of the prey, these are referred to as spirocysts.  For the purposes of this blog, we will be focusing on the class Anthozoa, the class belonging to sea anemones and corals.  In later posts, we will touch upon class Medusae.

Any species of coral can have many different kinds of cnidae on itself. If you have ever been stung by a coral, you have personally experienced these cnidae. Most people can walk away from a sting from a regular coral or sea anemone relatively unharmed, but fish and other corals may not be so lucky.

Now for some information on less scary members of the class anthozoa....

These are just some of the corals and anemones in my 65gal tank at home. Supported by metal halide lamps, these corals thrive in a perfectly mimicked community. Today i will point out some interesting facts about zoanthids (center), duncans, (top & bottom left) and the min-max anemone.  In the following postings, I will feature select species.

Zoanthids (center), which are commonly misspelled as zooanthids, are relatively easy to care for and spread easily on rocks and can even grow on surfaces such as plastic and the pre-filter box that is featured on many large tanks. In this photo, they can be found in the center. But dont be fooled by their simple appearance. Some members of the order Zoantharia produce a toxin called palytoxin. While the concentration of the toxin in these species is hotly debated, if palytoxin enters the bloodstream via an open wound, the result can be fatal. Contrary to popular belief, palytoxin can enter the bloodstream through undamaged skin. When handeling Zoanthids, be sure to wear non-powdered latex gloves. The most common symptoms associated with palytoxin poisoning in humans are characterized by a bitter/metallic taste, abdominal cramps, nausea, vomiting, diarrhea, mild to acute lethargy, paresthesia, bradycardia, renal failure, impairment of sensation, muscle spasms, tremor myalgia, cyanosis, and respiratory distress. Seek immediate medical attention if you suspect that you have been exposed to palytoxin. You may also call the National Poison Hotline  (U.S.) 1-800-222-1222. 

  Photo credit: AG Photo