the reproductive system of a sand dollar
The Sand Dollar, live all other echinoderms, has a very unique way of reproducing. Unlike most organisms, the male and female don't even have to touch. Here's how it works:
1) Depending on the season, and on the proximity of another sand dollar, the female will release her eggs into the open water. Then, the male will release his sperm into open water where the eggs will be fertilized.
2) Certain species of Sand Dollars are hermaphroditic, meaning that they produce both eggs AND sperm. Therefore, when they release the eggs and sperm into the water they have a much higher chance of one of the eggs actually getting fertilized.
1) Depending on the season, and on the proximity of another sand dollar, the female will release her eggs into the open water. Then, the male will release his sperm into open water where the eggs will be fertilized.
2) Certain species of Sand Dollars are hermaphroditic, meaning that they produce both eggs AND sperm. Therefore, when they release the eggs and sperm into the water they have a much higher chance of one of the eggs actually getting fertilized.
references
http://www.madsci.org/posts/archives/oct99/939998242.Gb.r.html
http://answers.ask.com/Science/Biology/how_do_sand_dollars_reproduce
http://echinodermata.wordpress.com/2009/04/02/body-systems-part-one-reproductive-system/
http://answers.ask.com/Science/Biology/how_do_sand_dollars_reproduce
http://echinodermata.wordpress.com/2009/04/02/body-systems-part-one-reproductive-system/