The Great Barrier Reef Gbr - amazonia.fiocruz.br

Https://amazonia.fiocruz.br/scdp/essay/writing-practice-test-online/the-development-of-ai-in-the-ai.php crown-of-thorns starfishAcanthaster planci Barried, is a large starfish that preys upon hard, or stony, coral polyps Scleractinia. The crown-of-thorns starfish receives its name from venomous thorn-like spines that cover its upper surface, resembling the biblical crown of thorns. It is one of the largest starfish in the world. It is perhaps most common in Australia, but can occur at tropical and subtropical latitudes from the Red Sea and the east African coast across the Indian Ocean, and across the Pacific Ocean to the west coast of Central America.

The study’s co-author Jodie Rummer said the outlook for the species is “daunting.”

It occurs where coral reefs or hard coral communities occur in this region. The body form of the crown-of-thorns starfish is fundamentally the same as that of a typical starfishwith a central disk and radiating arms.

Its special traits, however, include being disc-shaped, multiple-armed, flexible, prehensileand heavily spined, and having a large ratio of stomach surface to body mass. In being multiple-armed, it has lost the five-fold symmetry pentamerism typical of Gbrr, although it begins its life cycle with this symmetry. The animal has true image forming vision. The underside of each arm has a series of closely fitting plates which form a groove and extend in rows to the mouth.

Euri Gold Farms

The long, sharp spines on the sides of the starfish's arms and upper aboral surface resemble thorns and create a crown-like shape, giving the creature its name. The spines are stiff and very sharp, and readily pierce through soft surfaces.

Despite the battery of sharp spines on the aboral surface and blunt spines on the oral surface, the crown-of-thorns starfish's general body surface is membranous and soft. When the starfish is removed from the water, the body surface ruptures and the body fluid leaks out, so the body collapses and flattens.

Journey to net zero

The spines bend over and flatten, as well. They recover their shape when reimmersed, if they are still alive. The family Acanthasteridae is monogeneric ; its position within the Asteroides is unsettled. It is generally recognized as a distinctly isolated taxon. Recently, Paleontologist Daniel Blake concluded from comparative morphology studies of Acanthaster planci that it has strong similarities with various members of the Oreasteridae. He transferred Acanthasteridae from the Spinulosida to the Valvatida and assigned it a position near to the Oreasteridae, from which it appears to be derived.

There is a complication, however, in that Acanthaster is not a monospecific genus and any consideration of the genus must also take into account another species, Acanthaster brevispinuswhich lives in a completely different environment. Acanthaster planci has a long history in the scientific literature with great confusion in the generic and species names from the outset, with a long list of complex synonyms. Later, Carl Linnaeus described it as Asterias planci based on an illustration by Plancus and Gualtieriwhen he introduced his system of binomial nomenclature. No type specimens are known; the specimen described by Plancus and Gualtieri is no longer extant.]