a paired or unpaired opening in cyclostomes and some bony fishes that connects the body cavity to the environment and that serves to eliminate eggs and sperm .
What is the genital pore?
genital pore: the common external opening of the male and female reproductive systems . ... a small collection of cells in a larval organism from which the reproductive tract will develop.
What is genital pores in earthworms?
A pair of male genital pores is situated ventrally on segment 18 . Genital papillae may also be present ventrally. As with all earthworms, development of young is without a larval stage and takes place in cocoons. Pheretima are generally nocturnal, like most earthworms, and have an aversion to light.
Where are male genital pores in earthworms?
A pair of male genital pores is present on the ventro-lateral sides of the 18th segment .
What is the function of the female pores on the ventral side of segment 14?
Openings to the oviducts are found at segment 14, counting from the anterior end. These female pores release the eggs . Sperm ducts can be found on segment 15. The clitellum is the enlarged structure that begins at segment 31.
What is the genital aperture?
genital aperture: 1. The genital opening . 2. (NEMATA) When a cloaca is present, the anus.
How many male genital pores are on the earthworm?
On the ventral side of 18 th segment, prostatic duct opens via a male genital aperture. Hence, each genital aperture has three distinct apertures , two of the vasa deferentia and one of the prostatic gland. In earthworm the prostatic secretion is useful for the activation of sperms.
How many hearts does an earthworm have?
Heartbeats: Worms don't have just one heart. They have FIVE ! But their hearts and circulatory system aren't as complicated as ours — maybe because their blood doesn't have to go to so many body parts. Moving around: Worms have two kinds of muscles beneath their skin.
How can you tell a male from a female worm?
Try to identify reproductive adults: those earthworms will have a well-defined clitellum . The clitellum is usually a different colour than the earthworm's body and located close to the head of the earthworm. The clitellum is normally greyish-white, but it can also be bright orange within the same species.
What type of nervous system do earthworms have?
Cerebral ganglion
The earthworm's ‘brain'. Earthworms have a simple nervous system . The cerebral ganglion is connected to a ventral nerve cord that runs the length of the body. Each segment is connected to this cord, allowing earthworms to move and respond to light, touch, chemicals, vibrations and more.
Which segment of earthworm has female and male genital aperture?
Oviducts are a short conical funnel. they are ciliated. Both the oviducts converge and form a single female genital aperture at the 14th segment .
How do earthworms help farmers?
Worms help to increase the amount of air and water that gets into the soil . They break down organic matter, like leaves and grass into things that plants can use. When they eat, they leave behind castings that are a very valuable type of fertilizer. Earthworms are like free farm help.
Are worms nocturnal?
During the day earthworms mostly stay in their burrows underground. At night they come up near or on to the surface to feed . If the air it is too cold or too dry, they stay down in the soil. Some species also come on to the surface during the day if it is raining.
What are the large pores in earthworms called?
The clitellum is a swelling of the body found in sexually mature worms and is active in the formation of an egg capsule, or cocoon. Eggs are produced in the ovaries and pass out of the body through female genital pores.
Which side of the worm is darker?
The dorsal surface of some species of earthworms is darker than its ventral surface. The bottom-side of an animal is called the ventral surface. In many animals, the ventral surface is a lighter colour or shade than the dorsal surface.
What is the easiest system to observe in the earthworm?
An earthworm has a very simple nervous system . A ventral nerve cord which runs the entire length of its body connects to the cerebral ganglion, which is an earthworm's brain. Each segment is connected to the cord so that they can sense light and touch, and can move.
