Other Free Encyclopedias » Animal Life Resource » Mollusks, Crustaceans, and Related Species » Peanut Worms: Sipuncula - Physical Characteristics, Behavior And Reproduction, No Common Name (sipunculus Nudus): Species Account - GEOGRAPHIC RANGE, HABITAT, DIET, PEANUT WORMS AND PEOPLE, CONSERVATION STATUS

Peanut Worms: Sipuncula - Behavior And Reproduction

species reproduce body reproductive

Most peanut worms quickly withdraw their introverts when disturbed and avoid light by retreating into their burrows or rock crevices. They use their introvert hooks and muscles to pull their bodies forward. Swimming is not common and is accomplished by simply jerking the body trunk in all directions.

Many peanut worms can replace missing tentacles and introverts. Some species can regenerate portions of the digestive tract and body trunk. Others reproduce by purposely dividing their bodies. Each body part then develops all the necessary missing parts. This type of reproduction is called budding, or asexual (ay-SEK-shuh-wuhl) reproduction. Asexual reproduction does not involve mating or male or female reproductive systems.

Most peanut worms require both males and females to reproduce. Only one species has individuals with both male and female reproductive organs. Another species is able to reproduce without fertilization (FUR-teh-lih-ZAY-shun), or the combining of egg and sperm to start development. The sexes are identical to each other, and their reproductive organs are present only while they reproduce. Eggs and sperm are released into the coelom, where they are collected by the kidneylike organs and expelled into the water. Fertilization takes place outside of the body. Peanut worms develop in a variety of ways. Some species develop from eggs directly into miniature versions of the adults, while others must first go through various free-swimming larval stages before becoming young worms.

Peanut Worms: Sipuncula - No Common Name (sipunculus Nudus): Species Account [next] [back] Peanut Worms: Sipuncula - Physical Characteristics

User Comments

Your email address will be altered so spam harvesting bots can't read it easily.
Hide my email completely instead?

Cancel or

Vote down Vote up

over 11 years ago

I was wondering if you knew if peanut worms sometimes divide their bodies when put under stress as a defense mechanism. I ask this because I was observing a peanut worm in my hand dividing its body. It seemed only to divide when I was touching it with my finger. It divided a total number of three times within the course of ten minutes. Also, the segments that were divided continued to move only for about three minutes. After three minutes they just laid there. Please e-mail me back with any type of comment that might help me find an answer to my question. Thank you.