Most sea cucumbers undergo an external form of sexual reproduction. Most sea cucumbers are either of a male or female gender, producing their respective gametes. Some sea cucumbers are hermaphodites and produce both egg and sperm cells. If a sea cucumber can produce both types of gametes, they can reproduce without the presence of a mate. It is more common for a sea cucumber to reproduce sexually. Sea cucumbers reproduce by spawning. Females that are ready to produce offspring will release pheromones which trigger male cucumbers to spawn. Gametes that are released into the ocean will eventually meet up where the egg would be fertilized. The reproduction of sea cucumbers is most likely to ooccur where there is a large population of that species. Once fertilized, the egg will float because it has died or sink to the ocean floor before hatching.