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The starfish is found on hard bottoms and under stones and seaweed where it mainly feeds on other echinoderms and on bivalve molluscs. [3] In most of its range, it undergoes sexual reproduction in the winter, while in the summer, it proliferates by asexual reproduction . [ 4 ]
Asexual reproduction in starfish takes place by fission or through autotomy of arms. In fission, the central disc breaks into two pieces and each portion then regenerates the missing parts. In autotomy, an arm is shed with part of the central disc attached, which continues to live independently as a "comet", eventually growing a new set of arms.
Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea (/ ˌ æ s t ə ˈ r ɔɪ d i ə /). Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish are also known as asteroids due to being in the class
2.5 Timeline of accomplishments. 2.6 ... Printable version ... because their work on the pH change in sea urchin and starfish eggs upon fertilization was an excellent ...
Fertilization is the fusion of gametes to produce a new organism. In animals, the process involves a sperm fusing with an ovum, which eventually leads to the development of an embryo. Depending on the animal species, the process can occur within the body of the female in internal fertilization, or outside in the case of external fertilization.
The starfish engages in external fertilization in which the female releases the eggs and the male releases the sperm. Fertilization occurs in the water column. Its breeding season is the summer. During this time, male and female starfish can be found extremely close or even on top of one another.
A marine parasite expert stated that the starfish was an important member of the marine community and that if it were removed, marine biodiversity in the area would be threatened. [5] In a study published in 2013, Ochitophrya stellarum, the parasitic ciliate, was discovered in 2007 in the tissues of blue crabs.
This concentration of individuals enhances the chance of fertilization when the gametes are liberated into the sea. The larvae form part of the zooplankton and drift with the currents. After passing through several developmental stages they settle on the seabed, usually among seagrass, and undergo metamorphosis into juvenile starfish.