Context: Some polychaetes breed only once in their lives, while others breed almost continuously or through several breeding seasons. While most polychaetes remain of one sex all their lives, a significant percentage of species are full hermaphrodites or change sex during their lives. Most polychaetes whose reproduction has been studied lack permanent gonads, and it is uncertain how they produce ova and sperm. In a few species the rear of the body splits off and becomes a separate individual that lives just long enough to swim to a suitable environment, usually near the surface, and spawn.

Question: What do some non-single-sex polychaetes do?
Answer: change sex

Question: What are most polychaetes lacking for reproduction?
Answer: permanent gonads

Question: How do some annelids get a one-time chance at a better spawning spot?
Answer: the rear of the body splits off and becomes a separate individual

Question: What do all non-single-sex polychaetes do?
Answer: Unanswerable

Question: What are no polychaetes lacking for reproduction?
Answer: Unanswerable

Question: How do some annelids get a three-time chance at a better spawning spot?
Answer: Unanswerable

Question: How many polychaetes breed an infinite amount of times?
Answer: Unanswerable