Reproduction on Shalimar


It is difficult, on Shalimar, to ensure that life will continue. Although most of the time Shalimar is a tropical planet, covered by lush vegetation and watered by warm rains, Shalimar also has dark, cold periods.

Heynar, the system's sun, is one member of a double star system: the other star is dark, small, and very distant. About every 20,000 years this dark star passes closer to Heynar. The gravity of the dark star is not great enough to upset the planetary system, but it does cause changes in the orbits of the dark debris at the far edges of the solar system. Some of this space debris enters the inner solar system and bombards the planets and moons there. Sometimes Shalimar is hit by a succession of small rocks and stones: at other times it is smashed by one or more huge meteorites. The results of a violent collision may include a very cold period caused by dust from the impact blocking out the sun's heat and light. Earthquakes may result, or tidal waves, or huge fires. As a result, there are periods on Shalimar when no active life can be found.

Life survives these dark periods in the form of zoospores. These are tiny, tough-skinned single cells that can retain their vitality for hundreds, perhaps thousands, of years. All the life forms on Shalimar use this way of continuing their kind.

Shalimar's plants form zoospores by cell division, sometimes after the fusion of the runners of adjoining species of plants. The animals also form zoospores. The zoospores are formed by special nurturing pouches in the lining of the intestinal tract. When the cells are mature, the nurturing pouches open and the zoospores are excreted with bodily wastes.

Although these animals do not reproduce sexually, the method that they use does allow for some chromosomal exchanges and additions. It also allows the organisms to respond to scarcity or plenty in their environment.

This diagram shows a section of a digestive tract from a triangularian. Food is in short supply, and the nurturing pouches along the digestive tract are forming zoospores slowly and releasing them when they are mature. This ensures a supply of dormant cells which are genetically identical with their parent.

This diagram shows zoospore formation in a time of plenty. Many zoospores are produced, and the high volume of food consumed stretches the intestine so that the nurturing pouches are partially open. As the animals are consuming organic food, genetic material from the consumed and broken cells sometimes finds its way into the nurturing pouches and is included in the zoospore. Although most of the cells with genetic additions do not work well enough to develop into new organisms, a few do survive and grow, developing into animals which differ from their parents.





© Elizabeth Anne Viau, 1996. This material may be used freely for instructional purposes but not sold for a price beyond the cost of reproduction. Please e-mail me at eviau@earthlink.net if you use this material. I'd be interested to know how it works for you!