Were You Previously Informed?
Both the phrases Did You Know? and Were You Aware? are copyrighted!
Were You Previously Informed?
Earthworms are an integral part of the earth! They eat the soil, and then they fertilize it and make it nice and rich over time, making mediocre farmland into farmland people will sell their souls for! Without Earthworms, most of the soil in the world would be somewhat infertile. Thank the Lord for the Earthworms!
Were You Previously Informed?
The largest earthworm ever found was in South Africa and measured 22 feet from its nose to the tip of its tail!
Were You Previously Informed?
Earthworms are enjoyed raw by children, cooked and fried by adults, and cause no parasitic infections, contrary to popular belief. Also, fear of worms is scoleciphobia or vemiphobia.
Tuesday, March 6, 2007
Excretion
-Annelids produce two kinds of waste, solid and metabolism wastes.
-The solid wastes are excreted by anus.
-The wastes that come from metabolism are excreted by nephridia.
-A pair of nephridia in each of the septa excretes the wastes out of the body to the outside.
Example (Earthworms):
-The excretory system in earthworms consists of a pair of nephridia for each segment.
-Each nephridia consists of a long, convoluted tubule that begins with a ciliated funnel.
-Fluid is carried into the funnel by the beating of the cilia and is excreted through an outer pore.
-The solid wastes are excreted by anus.
-The wastes that come from metabolism are excreted by nephridia.
-A pair of nephridia in each of the septa excretes the wastes out of the body to the outside.
Example (Earthworms):
-The excretory system in earthworms consists of a pair of nephridia for each segment.
-Each nephridia consists of a long, convoluted tubule that begins with a ciliated funnel.
-Fluid is carried into the funnel by the beating of the cilia and is excreted through an outer pore.
Feeding
-Some annelids feed on a wide variety of organic matter, primarily detritus and algae.
-They are considered to be beneficial animals because they eat when moving through the ground.
-When the annelid eats the food, the extra it doesn't need is excreted in the form of castings.
-These casting are high in nutrients and are then used for food for other animals.
-Because the annelids burrow into the ground to eat, the rain water seeps deeper into the ground to help get more water to the plants.
-Some annelids are sanguivorous, that is they feed as blood sucking parasites on preferred hosts.
-If they cant find the preferred hosts, they will find another suitable host to feed on.
-Some feed on humans and other mammals, but some feed on fish, frogs,turtles, etc...
-Some even feed on other sanguivorous annelids.
-The annelid can ingest a large quantity of blood, which it then goes into a dark spot to digest it. The digestion is slow, and lets the annelid survive a long time without feeding.
-They are considered to be beneficial animals because they eat when moving through the ground.
-When the annelid eats the food, the extra it doesn't need is excreted in the form of castings.
-These casting are high in nutrients and are then used for food for other animals.
-Because the annelids burrow into the ground to eat, the rain water seeps deeper into the ground to help get more water to the plants.
-Some annelids are sanguivorous, that is they feed as blood sucking parasites on preferred hosts.
-If they cant find the preferred hosts, they will find another suitable host to feed on.
-Some feed on humans and other mammals, but some feed on fish, frogs,turtles, etc...
-Some even feed on other sanguivorous annelids.
-The annelid can ingest a large quantity of blood, which it then goes into a dark spot to digest it. The digestion is slow, and lets the annelid survive a long time without feeding.
Habitat and adaptations
Earthworms
-Earthworms are found in many terrestrial environments ranging from semi-arid habitats to moist, well-vegetated areas.
-Some earthworms are found in wetter areas, or they can be found in soil, under logs, and usually come out of the soil after a heavy rain because it is becoming water-logged
Leeches:
-Most leeches are freshwater animals, but many terrestrial and marine species occur.
-Land leeches are common on the ground or in low foliage in wet rain forests. In drier forests they may be found on the ground in seepage moistened places. Most do not enter water and cannot swim, but can survive periods of immersion.
-Some species burrow in the soil where they can survive for many months even in a total lack of environmental water.
-Earthworms are found in many terrestrial environments ranging from semi-arid habitats to moist, well-vegetated areas.
-Some earthworms are found in wetter areas, or they can be found in soil, under logs, and usually come out of the soil after a heavy rain because it is becoming water-logged
Leeches:
-Most leeches are freshwater animals, but many terrestrial and marine species occur.
-Land leeches are common on the ground or in low foliage in wet rain forests. In drier forests they may be found on the ground in seepage moistened places. Most do not enter water and cannot swim, but can survive periods of immersion.
-Some species burrow in the soil where they can survive for many months even in a total lack of environmental water.
Monday, March 5, 2007
Reproduction
-Depending on the species, annelids can reproduce sexually or asexually.
Asexual:
-fission is a method used by some annelids and allows them to reproduce quickly.
-the posterior end of the annelid breaks off and forms into a new worm.
Lumbriculus and Aulophorus (different kinds of annelids) for example, are known to reproduce by the body breaking into such fragments.
Sexual:
-Some annelida species are hermaphroditic, while others have distinct sexes.
-Most annelida reproduce by copulation.
-Two worms which are attracted by each other's secretions lay their bodies together with their heads pointing opposite directions. The fluid is transferred from the male pore to the other worm.
-Some annelida transfer sperm differently, by means of using a spermathecae (sperm storing chambers)
-The clitellum secretes a muscus that makes a 'coocon' around the egg and start to develop.
Asexual:
-fission is a method used by some annelids and allows them to reproduce quickly.
-the posterior end of the annelid breaks off and forms into a new worm.
Lumbriculus and Aulophorus (different kinds of annelids) for example, are known to reproduce by the body breaking into such fragments.
Sexual:
-Some annelida species are hermaphroditic, while others have distinct sexes.
-Most annelida reproduce by copulation.
-Two worms which are attracted by each other's secretions lay their bodies together with their heads pointing opposite directions. The fluid is transferred from the male pore to the other worm.
-Some annelida transfer sperm differently, by means of using a spermathecae (sperm storing chambers)
-The clitellum secretes a muscus that makes a 'coocon' around the egg and start to develop.
General Characteristics
Annelids are triploblastic protosomes that have a complete coelom. They have a closed circulatory system (blood is contained inside blood vessels) and are segmented. The segmentations are called Septa.
Oligochaetes and Polychaetes typically have spacious coeloms, but in leeches, the coelom is filled in with tissue and reduced to a system of narrow canals.
Typically, each compartment corresponds to a single segment of the body, which also includes a portion of the nervous and circulatory systems, allowing it to function somewhat independently. This means that if part of it is cut off, it can still function without the other half since it has the nessecary parts in each segment!
Each segment is marked externally by something called an Annuli. Annelids have a wide variety of diets, including active and passive hunters, scavengers, filter feeders, deposit feeders, and blood-suckers. Annelids have two main blood vessel; dorsal and ventral blood vessel.
Oligochaetes and Polychaetes typically have spacious coeloms, but in leeches, the coelom is filled in with tissue and reduced to a system of narrow canals.
Typically, each compartment corresponds to a single segment of the body, which also includes a portion of the nervous and circulatory systems, allowing it to function somewhat independently. This means that if part of it is cut off, it can still function without the other half since it has the nessecary parts in each segment!
Each segment is marked externally by something called an Annuli. Annelids have a wide variety of diets, including active and passive hunters, scavengers, filter feeders, deposit feeders, and blood-suckers. Annelids have two main blood vessel; dorsal and ventral blood vessel.
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