are sea apples toxic to fish in a marine aquarium,if so how toxic?
Although they look quite benign, there are a number of sea cucumber species whose body walls and internal organs contain a toxin known as holothurin that can rapidly deplete your fish population. This is such an effective ichthyotoxin that natives in some parts of the Indo-Pacific will use the macerated bodies of certain sea cucumbers to incapacitate fish. It’s interesting to note that in most cases, sea cucumber toxins do not kill other invertebrates in the tank, only fish. However, studies have shown that the toxin actually will kill smaller invertebrates, including worms, cnidarians (i.e., Hydra) and mollusks. Holothurin can be released into the tank in several different ways. Two of these are defensive strategies, known as evisceration and Cuvierian tubule expulsion. Evisceration, which is the more common of the two strategies, can take two forms, depending on the species of sea cucumber in question. In one form the cloaca ruptures and the respiratory trees, the digestive tract and
