1. Environmental factors. The presence or absence of symbionts in corals can be influenced by environmental factors such as temperature, light, and nutrient availability. For example, corals that live in high-temperature environments may be more likely to lose their symbionts than corals that live in cooler environments.
2. Host-symbiont compatibility. The compatibility between a coral and its symbionts is also a factor in whether or not the symbionts will be passed on to offspring. Some corals are more compatible with certain types of symbionts than others. If a coral is not compatible with a particular type of symbiont, the symbionts may not be able to survive in the coral's tissues.
3. Competition. Corals may also compete with other organisms for symbionts. For example, some species of algae can compete with corals for symbionts. If a coral is unable to compete successfully for symbionts, it may lose its symbionts to other organisms.
4. Stress. Stress can also cause corals to lose their symbionts. Stress can be caused by a variety of factors, such as pollution, disease, or predation. If a coral is stressed, it may not be able to provide the necessary conditions for its symbionts to survive.
As a result of these factors, corals do not always pass on symbionts to their offspring. This can have a negative impact on the coral's health and survival, as symbionts provide corals with essential nutrients and energy.
