Venom of Crown of Thorns Starfish

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  • Topic: Crown-of-thorns starfish, Coral reef, Great Barrier Reef
  • Pages : 5 (1581 words )
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  • Published : May 2, 2013
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Adam Holena
Physiology
Venom Research Paper
5/2/2013

Crown of Thorns Starfish
To many tourists the Great Barrier Reef is an exciting and relaxing destination to travel to. It holds beauty in its waters that are difficult to find anywhere else. Within the beauty however lies many varieties of marine organisms that all can inflict great harm to humans. One such organism is the Crown of thorns starfish (Acanthaster planci). When most people hear of the organism starfish, they think of this barely mobile, harmless creature that lives on the bottom of the ocean. This specific species of starfish, however; is quite different from those commonly referred to.

The crown of thorns starfish lives predominantly in the Great Barrier Reef, but can also be found in along sea beds, and intertidal zones of tropical and subtropical latitudes. The shaping of the crown of thorns starfish is the same as most starfish, including the traits of having a center mass with protruding appendages used for movement. This starfish differs from the normal Asteroidea family of starfish in that it is not limited to the five arms, and is heavily armed with spines covering its dorsal surface. An adult of this species ranges from 25 to 35cm in size and is seen with up to 21 arms. The coloration of these animals is usually on the dull side of pale brown, but depending on their location, are often seen with a vivid color scheme. Figure 1: A picture of a Acanthaster planci depicting an example with a vivid color scheme. (“Acathancaster planci”, 2011)

If the spines were removed from this organism, the surface of it would be very soft, as the majority of the shape this organism has comes from the water that is contained within it. The crown of thorns starfish is known to thrive off of the coral reef that it lives amongst, where it digests the coral using its gastric juices to liquefy the coral to a state for consumption (“Crown-of-thorns Starfish”, 2013). Because of the manner that these starfish live off of the coral reefs, there has within the recent years been an increase in the numbers of these organisms living on the reef beds, causing great devastation when they all begin to feed. One adult starfish can be known to consume on average, 478 cm2 of coral within one day alone. It is easy to see then how these creatures become an extreme threat to the coral ecosystems present in the oceans. In addition to feeding on the coral reefs, these creatures are known to feed off of other sessile animals and dead organisms as well, classifying them as opportunistic carnivores (Ault, 2011). Many different attempts have been made to limit the number of these starfish in areas faced with an over-abundance of them. These attempts include physically moving them, placing up barriers to prevent them from reaching the reefs, or even studies to see whether or not there are any valuable components within the starfish that could be used as a resource in some way (“Acathanster planci, 2011).

Contrary to much knowledge of the starfish family, this species contains within it deadly venom that is uses mostly in a protective manner. The spines of these creatures are sharpened to be able to penetrate the skin. Once in the skin of is predator, the spines will break off leaving some of the tissue with glands in them behind. This initial penetration itself is known to be very painful, but that is not the end of the damage that the starfish will do to its attacker. The glands that the tissues hold in the spines are known to produce different compounds that are venomous to other organisms. Some of these compounds include hemolytic and myotoxic PLA2 enzymes, anticoagulants, and plancitoxins. The combination of all of these different compounds provides ample protection from the predators that this creature faces when conduction its feeding, which usually requires little movement leaving this organism subject to attack.

The hemolytic and myotoxic PLA2 (phospholipase A2)...
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