The crown-of-thorns starfish (Acanthaster planci) is a red-colored starfish with thorn-like spines sprouting all over its body for protection. They grow to a diameter of up to 40 cm across and have 12 to 19 arms extending from their center.
The starfish is a coral reef predator (a corallivore) and preys on the coral polyps by climbing onto them, extruding its stomach over them, and releasing digestive enzymes to then absorb the liquified tissue. They feed alone at night, maintaining a constant distance between themselves and other crown-of-thorns starfish. During times of food shortage, these creatures can live on their energy reserves for over six months.
At the conclusion of the effort, the World Wildlife Fund for Nature (WWF) reported that a total of 5,212 COTS were removed from Apo Reef alone. The WWF reported that the first COTS cleanup was completed in January by volunteer divers from the group and the Department of Environment and Natural Resources (DENR). This effort netted 704 of the coral-eating pests...
In cases where you have relatively young or recovering reefs, we choose to control COTS populations because most Philippine reefs are generally not in very good shape. They need the opportunity to recover. Plus, close to 50 percent of Filipinos living along our coastlines depends on seafood and many reef species as their sources of food, said WWF president Lorenzo Tan."Physical removal of the COTS is the only practical way to spare our reefs damage, the WWF added.
The starfish's sheer bulk and dense coat of stinging spines that measure up to 5 centimeters long proved to be an effective deterrent against most predators. The starfish' natural predators are the Napoleon wrasse, Harlequin shrimp, and Giant triton.
If accidentally touched or stepped on by humans, the starfish's long spines are capable of pricking and stinging, inflicting great pain that can last for hours, as well as nausea and vomiting. Often, the area around the puncture turns a dark blue (erythema) and begins to swell (edema). The swelling may persist for a number of days.
Source: Philippine Star
