Those apart of the Annelida phylum are most commonly referred to as annelids, however they are also known as ringed worms, or segmented worms. With about 17,000 known species, these organisms are found all around the world in many different habitats. These organisms are bilaterally symmetrical and come in many different shapes, sizes, and colours. Annelids play one of the most crucial roles in the ecosystem, considering that it is their job to modify the soil and sediment, thus keeping the land fertile. These organisms can be as small as 1 centimeter to approximately 135 centimeters long.
MOVEMENT: Annelids move by extending their body, latching onto a surface with setae, and then flexing their body muscles. In order for this organism to move forward, circular muscles at the front-end flex, which then extends the head forward. A wavelike contraction then passes through to the rear end. When the wave of contraction gets close to the middle area of the body, lengthy muscles contract, which shortens the area. After this A wave of contraction of lengthy muscles will occur. This motion is continued repeatedly until the annelid reaches its destination.
BODY COVERINGS: Annelids have three cell layers: the ectoderm, the endoderm, and separating those to layers, the mesoderm. These organisms have and outer case of muscle, epidermis and cuticle. Their bodies are covered with setae, which is what these use organisms use to anchor onto surfaces, and allows annelids to swim better. By means of protection, these organisms have the ability to regrow body segments. Annelids have an organ-system level of organization.
SUPPORT: Annelids are invertebrates; however, they have a different type of skeleton that play a role in keeping the shape of these organisms. Annelids have a water based skeleton, known as the hydrostatic skeleton, or hydroskeleton. Inside of annelids, there are two coelomates, which are hollow body cavities. The coelomate is enclosed by a ring of muscles, which flex in order to transport the supportive coelom fluid within each cavity. This interaction creates hydrostatic pressure, which is what maintains the shape of annelids, and prevents them from being flat like flatworms.
NUTRITION: In order for these organisms to obtain their source of nutrition, annelids must use their mouth, located on the bottom of their head. Once the food is in their mouth, it travels to the gut which then goes to the anus at the end of the annelid’s body. These organisms consume food such as dead plants and animals.
RESPIRATION: Since most annelids lack specialized organs for gas exchange, these organisms normally obtain oxygen right through their body walls. Aquatic annelids have gills, which are thin-walled and feathery. These gills allow gas exchange to occur between the annelid’s blood and the environment.
CIRCULATORY: Annelids have a closed circulatory system, meaning that their blood is all contained inside of hearts and blood vessels. This blood stays there, and doesn’t drain out into the body cavities. There organisms have two major blood vessels which run down of the annelid, connecting by interspersed capillary beds.
EXCRETION: Annelids are capable of producing two different types of waste: solid and metabolism waste. To remove solid waste, the waste is simply released from the anus of the annelid, which is located at the rear end of their bodies. To remove metabolism waste, the waste releases from nephridia, which is a tubule which opens to the exterior. A pair if nephridia which are found in the septa, get rid of the metabolic waste within the annelid’s body.
RESPONSE: These organisms have basic nervous systems, consisting of a double nerve cord which runs along the bottom, which an extended ganglion in each segment. The ganglion located in the head area serves as a brain to annelids. Depending on the annelids habitat, there organism can be light-sensitive, reactive to chemical stimuli, or sensitive to touch. Simplistic eyespots and noticeable eyes on stalks can help these organisms see things such as light, prey, and predators. Tentacles and palps help annelids sense chemicals, and help them feel and touch objects.
REPRODUCTION: Annelids have the ability to produce both sexually and asexually. Annelids are hermaphroditic, meaning that they possess both male and female sex organs. These organisms can either self-fertilize, or find a mate. Once the eggs are fertilized, they will lay eggs which will eventually become planktonic larvae. Asexually, these organisms reproduce by division or fission, which is when a piece of the annelid breaks off and grows into a new annelid.
MOVEMENT: Annelids move by extending their body, latching onto a surface with setae, and then flexing their body muscles. In order for this organism to move forward, circular muscles at the front-end flex, which then extends the head forward. A wavelike contraction then passes through to the rear end. When the wave of contraction gets close to the middle area of the body, lengthy muscles contract, which shortens the area. After this A wave of contraction of lengthy muscles will occur. This motion is continued repeatedly until the annelid reaches its destination.
BODY COVERINGS: Annelids have three cell layers: the ectoderm, the endoderm, and separating those to layers, the mesoderm. These organisms have and outer case of muscle, epidermis and cuticle. Their bodies are covered with setae, which is what these use organisms use to anchor onto surfaces, and allows annelids to swim better. By means of protection, these organisms have the ability to regrow body segments. Annelids have an organ-system level of organization.
SUPPORT: Annelids are invertebrates; however, they have a different type of skeleton that play a role in keeping the shape of these organisms. Annelids have a water based skeleton, known as the hydrostatic skeleton, or hydroskeleton. Inside of annelids, there are two coelomates, which are hollow body cavities. The coelomate is enclosed by a ring of muscles, which flex in order to transport the supportive coelom fluid within each cavity. This interaction creates hydrostatic pressure, which is what maintains the shape of annelids, and prevents them from being flat like flatworms.
NUTRITION: In order for these organisms to obtain their source of nutrition, annelids must use their mouth, located on the bottom of their head. Once the food is in their mouth, it travels to the gut which then goes to the anus at the end of the annelid’s body. These organisms consume food such as dead plants and animals.
RESPIRATION: Since most annelids lack specialized organs for gas exchange, these organisms normally obtain oxygen right through their body walls. Aquatic annelids have gills, which are thin-walled and feathery. These gills allow gas exchange to occur between the annelid’s blood and the environment.
CIRCULATORY: Annelids have a closed circulatory system, meaning that their blood is all contained inside of hearts and blood vessels. This blood stays there, and doesn’t drain out into the body cavities. There organisms have two major blood vessels which run down of the annelid, connecting by interspersed capillary beds.
EXCRETION: Annelids are capable of producing two different types of waste: solid and metabolism waste. To remove solid waste, the waste is simply released from the anus of the annelid, which is located at the rear end of their bodies. To remove metabolism waste, the waste releases from nephridia, which is a tubule which opens to the exterior. A pair if nephridia which are found in the septa, get rid of the metabolic waste within the annelid’s body.
RESPONSE: These organisms have basic nervous systems, consisting of a double nerve cord which runs along the bottom, which an extended ganglion in each segment. The ganglion located in the head area serves as a brain to annelids. Depending on the annelids habitat, there organism can be light-sensitive, reactive to chemical stimuli, or sensitive to touch. Simplistic eyespots and noticeable eyes on stalks can help these organisms see things such as light, prey, and predators. Tentacles and palps help annelids sense chemicals, and help them feel and touch objects.
REPRODUCTION: Annelids have the ability to produce both sexually and asexually. Annelids are hermaphroditic, meaning that they possess both male and female sex organs. These organisms can either self-fertilize, or find a mate. Once the eggs are fertilized, they will lay eggs which will eventually become planktonic larvae. Asexually, these organisms reproduce by division or fission, which is when a piece of the annelid breaks off and grows into a new annelid.