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Starfish sometimes have negative effects on ecosystems. Outbreaks of crown-of-thorns starfish have caused damage to coral reefs in Northeast Australia and French Polynesia. [59] [70] A study in Polynesia found that coral cover declined drastically with the arrival of migratory starfish in 2006, dropping from 50% to under 5% in three years.
The Asterozoa are a subphylum in the phylum Echinodermata, within the Eleutherozoa.Characteristics include a star-shaped body and radially divergent axes of symmetry. The subphylum includes the classes Asteroidea (the starfish or sea stars), Ophiuroidea (the brittle stars and basket stars), Somasteroidea (early asterozoans from which the other classes most likely evolved), and Stenuroidea ...
Symmetry is one class of patterns in nature whereby there is near-repetition of the pattern element, either by reflection or rotation. While sponges and placozoans represent two groups of animals which do not show any symmetry (i.e. are asymmetrical), the body plans of most multicellular organisms exhibit, and are defined by, some form of symmetry.
While the overall morphological processes have been well documented in many starfish, little is known regarding the underlying molecular mechanisms that mediate their regeneration. Moreover, some researchers hope starfish may one day serve as inspiration for therapeutics aiming to expand the extent to which humans can repair and replace damaged ...
A sea cucumber's larva is an 'auricularia' while a crinoid's is a 'vitellaria'. All these larvae are bilaterally symmetrical and have bands of cilia with which they swim; some, usually known as 'pluteus' larvae, have arms. When fully developed, they settle on the seabed to undergo metamorphosis, and the larval arms and gut degenerate.
The unusual animals have unique body plans arranged in five equal sections that differ greatly from the symmetric head-to-tail bodies of bilateral animals, which have left and right sides ...
Starfish larvae are bilaterally symmetric, whereas the adults have fivefold symmetry. Echinoderms (Greek for spiny skin) is a phylum which contains only marine invertebrates. The adults are recognizable by their radial symmetry (usually five-point) and include starfish, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies.
A species of pufferfish and two triggerfish have been observed to feed on crown-of-thorns starfish in the Red Sea, and although they may have some effect on the A. planci population, no evidence exists of systematic predation. [37] In the Indo-Pacific waters, white-spotted puffers, and Titan triggerfish have also been found to eat this starfish ...