Types of Sexual and Asexual Reproduction About Watch and Favorite Watch Watching this resources will notify you when proposed changes or new versions are created so you can keep track of improvements that have been made. Favorite Favoriting this resource allows you to save it in the “My Resources” tab of your account. There, you can easily access this resource later when you’re ready to customize it or assign it to your students. Types of Sexual and Asexual Reproduction Asexual and sexual reproduction, two methods of reproduction among animals, produce offspring that are clones or genetically unique. Learning Objective Discuss sexual and asexual reproduction methods Key Points Asexual reproduction includes fission , budding, fragmentation, and parthenogenesis , while sexual reproduction is achieved through the combination of reproductive cells from two individuals. The ability of a species to reproduce through fragmentation depends on the size of part that breaks off, while in binary fission , an individual splits off and forms two individuals of the same size. Budding may lead to the production of a completely new adult that forms away from the original body or may remain attached to the original body. Observed in invertebrates and some vertebrates, parthenogenesis produce offspring that may be either haploid or diploid .

Sexual reproduction, the production of an offspring with a new combination of genes , may also involve hermaphroditism in which an organism can self-fertilize or mate with another individual of the same species. Terms Methods of Reproduction: Asexual & Sexual Asexual Reproduction Asexual reproduction produces offspring that are genetically identical to the parent because the offspring are all clones of the original parent. This type of reproduction occurs in prokaryotic microorganisms (bacteria) and in some eukaryotic single-celled and multi-celled organisms. Animals may reproduce asexually through fission, budding, fragmentation, or parthenogenesis. Fission Fission, also called binary fission, occurs in prokaryotic microorganisms and in some invertebrate, multi-celled organisms. After a period of growth, an organism splits into two separate organisms. Some unicellular eukaryotic organisms undergo binary fission by mitosis . In other organisms, part of the individual separates, forming a second individual. This process occurs, for example, in many asteroid echinoderms through splitting of the central disk. Some sea anemones and some coral polyps also reproduce through fission .

Coral polyps reproduce asexually by fission, where an organism splits into two separate organisms. Budding Budding is a form of asexual reproduction that results from the outgrowth of a part of a cell or body region leading to a separation from the original organism into two individuals. Budding occurs commonly in some invertebrate animals such as corals and hydras . In hydras, a bud forms that develops into an adult, which breaks away from the main body; whereas in coral budding, the bud does not detach and multiplies as part of a new colony. Hydra reproduce asexually through budding, where a bud forms that develops into an adult and breaks away from the main body. Fragmentation Fragmentation is the breaking of the body into two parts with subsequent regeneration. If the animal is capable of fragmentation, and the part is big enough, a separate individual will regrow. Many sea stars reproduce asexually by fragmentation. For example, if the arm of an individual sea star is broken off it will regenerate a new sea star . Fishery workers have been known to try to kill the sea stars that eat their clam or oyster beds by cutting them in half and throwing them back into the ocean.

Unfortunately for the workers, the two parts can each regenerate a new half, resulting in twice as many sea stars to prey upon the oysters and clams. Fragmentation also occurs in annelid worms, turbellarians, and poriferans. Note that in fragmentation, there is generally a noticeable difference in the size of the individuals, whereas in fission, two individuals of approximately the same size are formed. Parthenogenesis Parthenogenesis is a form of asexual reproduction where an egg develops into a complete individual without being fertilized. The resulting offspring can be either haploid or diploid, depending on the process and the species. Parthenogenesis occurs in invertebrates such as water fleas, rotifers, aphids, stick insects, some ants, wasps, and bees. Bees use parthenogenesis to produce haploid males (drones) and diploid females (workers). If an egg is fertilized, a queen is produced. The queen bee controls the reproduction of the hive bees to regulate the type of bee produced. Some vertebrate animals, such as certain reptiles, amphibians, and fish, also reproduce through parthenogenesis.

Although more common in plants, parthenogenesis has been observed in animal species that were segregated by sex in terrestrial or marine zoos. Two Komodo dragons, a bonnethead shark, and a blacktip shark have produced parthenogenic young when the females have been isolated from males. Sexual Reproduction Sexual reproduction is the combination of (usually haploid, or having a single set of unpaired chromosomes) reproductive cells from two individuals to form a third (usually diploid, or having a pair of each type of chromosome) unique offspring. Sexual reproduction produces offspring with novel combinations of genes. This can be an adaptive advantage in unstable or unpredictable environments. As humans, we are used to thinking of animals as having two separate sexes, male and female, determined at conception. However, in the animal kingdom, there are many variations on this theme. Hermaphroditism Hermaphroditism occurs in animals where one individual has both male and female reproductive parts. Invertebrates, such as earthworms, slugs, tapeworms and snails, are often hermaphroditic. Hermaphrodites may self-fertilize or may mate with another of their species, fertilizing each other and both producing offspring.

Self fertilization is common in animals that have limited mobility or are not motile , such as barnacles and clams. Earthworms More information is available in an online Scientific American article . HOW ARE EARTHWORMS CONSTRUCTED? Here are some visible and invisible adaptations to admire about earthworm physique: The worm's streamlined body with no conspicuous appendages is an adaptation to living in narrow burrows underground In those narrow tunnels, antenna and fancy tails would just get in the way. Earthworms don't have eyes, but they do have light-sensitive cells scattered in their outer skin. These cells don't enable earthworms to see images, or forms, but they do give their skin the capacity to detect light and changes in light intensity. The worm's skin cells are also sensitive to touch and chemicals Earthworms have simple brains which specialize in directing body movement in response to light, and not much else. To show how simple the brain is, if an earthworm's brain is removed, changes in its general behavior are hardly noticeable Earthworms, as the drawing above shows, possess five hearts.

The calciferous glands shown between the hearts manage excess calcium in the worm's diet, a problem you may have if you eat a lot of dirt. Earthworms have no lungs. Their "breathing" consists of oxygen from the air passively diffusing through the skin into the body. One problem with having such permeable skin is that earthworms dry out easily, but not as easily as mollusks Each earthworm carries both male and female reproductive parts --they are, like snails and slugs, hermaphroditic WHEN CONDITIONS GET ROUGH.... When the soil gets very cold, very hot, very wet or very dry, it's hard on an earthworm. Survival strategies vary from species to species. A typical behavior is to tunnel deeper into the soil, to where conditions aren't so extreme. Some species, especially during hot, dry periods, do what's shown at the right. At a fair depth they roll themselves into balls and excrete mucous around themselves, creating a kind of cocoon. In such a state their body functions slow down drastically. They go into a kind of suspended animation, just waiting for soil conditions to improve.

When an animal goes into such a state in order to survive summer's hot, dry conditions, it's said that they estivate or "go into estivation." I found the earthworm shown above one day as I worked in the very dry soil of a garden. The earthworm was inside a very hard, dry clod of soil. While the picture was being taken it began moving, so this worm was very much alive, just "resting" until a good rain. HOW DO EARTHWORMS TRAVEL? The secret to earthworm travel lies in two things you can't see just by looking. Though earthworms have no bones, their complex system of muscles enables them to not only wiggle like crazy but also to very quickly alternate between being stubby and thick, and long and slender Earthworms possess tiny, practically invisible bristles, called setae (pronounced SEE-tee; singular form seta, pronounced SEE-tah), which usually are held inside their bodies. When the worms want to stay in their burrows, they jab their setae into the surrounding dirt, thus anchoring themselves in place. This comes in handy if a bird nabs a worm's head and tries to pull the worm from its burrow.

The setae anchor the worm so well that it may break before coming out. Here's how these two features enable earthworms to travel: Let's say that a worm in its burrow wants to move forward. First, using its complex musculature, it makes itself long. Then it anchors the front of its body by sticking its front setae into the soil. Now it pulls its rear end forward, making itself short and thick. Once the rear end is in place, the front setae are withdrawn from the soil, but setae on the rear end are stuck out, anchoring the rear end. Now the front end is free to shoot forward in the burrow as the worm makes itself long and slender. Then the whole process is repeated. HOW DO EARTHWORMS REPRODUCE? This matter is as complex as it is interesting, so put your mind in low gear and hold on... Here's a drawing to help you keep oriented: First of all, not every earthworm segment bears sex organs. Counting from the front, the worm's male sex cells lie in segments 10 and 11. From here the sperm pass through sperm ducts to two male genital openings on the bottom of segment 15.

On segments 9 and 10 there are two minuscule sacs called sperm receptacles, or pores, where, during earthworm sex, sperm are deposited. However, this is not where eggs are produced. The egg-producing ovaries reside in segment 13, from which eggs are released through the female pores into egg sacs in segment 14. Finally, there's a rubbery, arm-band-like thing covering the worm's body from segments 31 or 32 to 37, and this is called the clitellum. EARTHWORM click here . If you're sharp enough to be identifying earthworms, don't forget to post your IDs at the iNaturalist.Org website. Now, when two earthworms mate, they line up next to one another with their "heads" pointing in opposite directions. The clitellum of one worm lies opposite segments 9-11 of the other, which, you'll remember, contain the male parts. The worms now secrete tremendous amounts of mucus, until each is enclosed in a slime tube extending from segment 9 to the rear end of the clitellum at segment 37.

Now sperm are ejaculated from segment 15 and carried backward in tubes formed by grooves in the body touching the slime tube and the sperm pass to the sperm receptacles on segments 9 and 10 of the other worm. Then the earthworms go their different ways. Sex is done. However, that is not to say that eggs have been fertilized, because they haven't. It's just that now, in each worm's sperm receptacles, there are sperm from the other worm. The next step in producing baby earthworms comes when the earthworm is by itself. Its clitellum secretes a second mucous ring that slides forward over the worm's body. When the ring passes the openings in segment 14, several ripe eggs leave the body and stick to the ring. The ring keeps moving forward until it passes the sperm receptacles in segments 9 and 10, and here sperm come into contact with eggs. Finally, within the mucous ring, the eggs are fertilized. Now the ring containing the fertilized eggs slips off the worm's "head," seals at both ends, and becomes a sort of cocoon, which is left lying in the soil.

Ultimately the eggs hatch and tiny worms escape from the mucous ring, into the soil. The end. earthworm - Crassiclitellata, Terrimegadrili Introduction (Back to Top) Like insects, earthworms (Figure 1) are among the animals most frequently encountered by many Floridians. Our kids play with them (Figure 2 A, B) and dissect them in middle school biology, we fish with them, they crawl across our sidewalks and live in our flower pots. Despite this, their ecological and economic importance often goes unrecognized. Earthworms have several important ecological roles. Additionally, some species are used commercially for bait, animal feed, environmental remediation, and composting. Figure 1. Earthworms collected from a parking lot following a heavy rainfall. Photograph by William T. Crow , University of Florida. The term earthworm is commonly assigned to certain worms in the class Clitellata in the phylum Annelida. Annelid worms are distinguished from other important worms like nematodes by having a coelum or true body cavity, a circulatory system, and a body divided into segments.

Other familiar annelids are the Hirudinea (leeches), the Polychaeta (marine bristleworms), and the Enchytraeids (potworms). Within the order Opisthopora there are both aquatic and terrestrial species. We will use earthworm exclusively for terrestrial worms in the suborder Crassiclitellata. Figure 2 A, B. Earthworms are frequently encountered by many Floridians. A) Photograph by Emily E. Eubanks , University of Florida. B) Photograph by William T. Crow , University of Florida. Distribution (Back to Top) There are thousands of described species of earthworms and likely many thousands more that are yet to be described. Individual species are found in most habitats worldwide. Different earthworm species are found in natural, agricultural, and urban environments; as of the mid 1990s there were 51 earthworm species reported in Florida. The two most widely distributed wild earthworms in Florida are Amynthas corticis and A. gracilis. Some species such as Diplocardia floridana and D. mississippiensis are known to occur only in the northern portion of the state.

South Florida is the only location in the United States where some tropical earthworm species such as Metaphire posthuma are found. Some earthworm species are unique to Florida, including Diplocardia alba gravida, which has only been reported in Charlotte, De Soto, and Sarasota Counties, and D. vaili which has only been found in Liberty County. The most commonly cultivated earthworms in Florida are the ‘tiger worm’ (Eisenia fetida), the ‘red wiggler’ (E. andrei), and one type of ‘nightcrawler’ (Dendrobaena veneta). Morphology and Anatomy (Back to Top) Structurally, the first thing that is noted about earthworms is that the body is segmented, appearing as a series of aligned adjacent rings. Internally, each of these segments is separated by septa. The number of segments is fairly consistent within a species and can be useful for identification. Because the body is segmented in this fashion most earthworms can survive losing some posterior portions of their body to predation or injury, and many can regenerate the lost sections.

Moving from the anterior to the posterior, the first segment, surrounding the mouth (buccal cavity), is called the peristomium. On the peristomium is a bump or lobe called the prostomium; the shape of this feature is useful for species identification. The prostomium can be used as a flap to cover the mouth, but also has sensory functions, and can be used to grasp and draw food into the mouth. Below the peristomium is a region that, when the worm is relaxed, may be thicker than the posterior regions; this region contains the sexual organs and their related glands (Figure 3). Male and female paired genital pores on the ventral side of the body may or may not be visible to the naked eye. The next region is a smoother region on adult earthworms that may look like a saddle or belt surrounding the worm. This is called the clitellum (Figure 4) and is where the cocoon is formed. Figure 3. Diagram of the anterior portion of an earthworm. By Clive A. Edwards . Figure 4. The anterior region of an earthworm. Photograph by William T. Crow , University of Florida.

The shape and number of segments making up the clitellum are mostly uniform within species and are very useful diagnostic features. Posterior from this the worm appears fairly uniform until the final segment, called the periproct, where the anus is located.; Each of the earthworms segments, except for the peristomium and the periproct, have microscopic hair-like structures called setae that can be extended or contracted and serve a variety of functions. Most setae are used in locomotion, others have tactile functions, and some aid in copulation. Earthworms move by contracting circular muscles that reduce the circumference of the individual segments while expanding them longitudinally. This is similar to squeezing a balloon in the middle and having both ends bulge out. During expansion the earthworm extends its setae to ‘hold onto’ surfaces and pull the worm’s body forward during contraction. This gives earthworms an expanding/contracting movement ( Video from a non UF source- TeacherTube ) unlike the sinusoidal movement of nematodes and snakes or the gliding motion of slugs and planarians. Internally, earthworms are complex, having most major organ systems.

The circulatory system consists of three major blood vessels running the length of the worm, smaller blood vessels encircling the worm, and multiple ‘pseudo hearts’ that direct blood flow. The digestive system is divided into the buccal cavity (mouth), pharynx, esophagus, crop, gizzard, and intestine. While not having a true brain, earthworms have a ventral nerve cord that runs the length of the worm, a network of nerves that control the muscles, and various photo, chemo, and tactile receptors. Earthworms also have a complicated secretory/excretory system. The respiratory system of earthworms is not advanced, and gas exchange occurs through the cuticle, which is of necessity kept moistened by secretions or “slime.” Often earthworms come to the surface and migrate following rainstorms and are commonly observed on sidewalks and driveways (Figure 5). These worms die quickly when they get dry (Figure 6). Figure 5. Earthworms are a common sight on sidewalks after rain. Photograph by William T. Crow , University of Florida. Figure 6. Earthworms quickly dry up and die in sunlight. Photograph by William T. Crow , University of Florida.

Life Cycle (Back to Top) Earthworms are hermaphroditic, adult worms having both male and female sexual organs (Figure 7). Most species copulate and reproduce by cross-fertilization although a few species can reproduce by parthenogenesis (reproduction without fertilization). After copulation, the clitellum secretes a structure called a ‘cocoon’ into which the ova and spermatozoa are deposited, and within which fertilization of the ova occurs. After the worm produces the cocoon, the cocoon hardens to give protection to the developing eggs. For most species, a single juvenile hatches per cocoon, although some species produce multiple juveniles per cocoon. Depending on the species, earthworms produce as few as one to over a hundred cocoons per year and the cocoons can take from 3 weeks to 5 months to hatch. Most juvenile earthworms hatch with the same number of segments as they will have as an adult, the segments simply enlarging during growth. The juveniles generally look the same as adults except for the absence of reproductive organs. Figure 7. Diagram illustrating earthworm sexual organs. By Barrie Jamieson .

Earthworm species are generally categorized environmentally as being either epigeic, endogeic, and anecic. Epigeic species live in organic litter near the soil surface and generally have a short life cycle and high fecundity. Epigeic earthworms are most often used commercially for composting. Anecic species form permanant burrows, spend much of the day in the mineral horizon, but come to the surface to forage on litter and plant debris, often at night. The nightcrawlers that many are familiar with are anecic worms. Endogeic species live in the mineral soil horizons and seldom come to the surface, so these are infrequently encountered by humans. Most earthworms are omnivores, feeding on both decaying and live plant matter, fungi, bacteria, and microscopic animals. For most species, decomposing plant matter is the primary food source, although most of their nutrient needs are supplied by microorganisms ingested at the same time. The organic piles of waste left after digestion by earthworms are termed casts or castings.

Epigeic worm castings can be used for compost, and anecic worm castings are often left in small piles at the surface of the worms burrow where they are commonly observed (Figure 8). Endogeic worms ingest large amounts of soil as they burrow, digest the organic matter contained therein, and then expel the mineral component back into the burrow. Figure 8. Castings deposited by anecic worms at the surface of their burrow. Photograph by Josh Unruh , University of Florida. Ecological Importance (Back to Top) Earthworms have various important ecological roles. The most easily recognized is that of organic matter decomposition. Decomposing plant matter is ingested and then expelled in a more broken down form, greatly speeding up the decomposition process. Worm castings typically have higher microbial activity and higher concentration of plant-available nutrients than the original material and therefore earthworms aid in nutrient cycling. Additionally, activity of anecic worms moves organic matter from the soil surface deeper into the soil profile. Tunneling by earthworms helps break compaction which improves aeration and water infiltration in the soil profile. The castings and other organic residues from earthworms improve soil structure.

Earthworms provide a principal food source for various wildlife including birds, reptiles, insects, and moles (Figure 9). Figure 9. Ibis foraging for worms and other food in a Florida lawn. Photograph by Max R. Crow Jr. Economic Importance (Back to Top) Earthworms can have important indirect economic effects due to the ecological benefits outlined above. They make a healthier soil which improves plant growth and agricultural productivity. For this reason worms are viewed as a gardener’s friend and their presence and activity in gardens is generally encouraged (Figure 10). Vermiculture is the science of commercial earthworm production. Certain species of earthworms are produced commercially for various reasons. Some of the commercial uses for earthworms worldwide are as fish food, a component in animal and poultry feed, and for human consumption. These worms are used unprocessed in some cases, but typically are dried and processed into meal that is blended with other food sources. Figure 10. Earthworms are beneficial and their activity is encouraged by most gardeners. Photograph by William T. Crow , University of Florida. The primary commercial use for earthworms in Florida is as fish bait.

There are many worm farms in Florida that supply worms to bait shops. In the Apalachicola National Forest a cottage industry has evolved around the harvesting of a wild native earthworm Diplochardia mississippiensis for fish bait using the practice of ‘worm grunting.’ ( Video on YouTube ) Worm grunting uses seismic vibrations that result from scraping a wooden stake driven into the ground to force the worms to the surface. This practice is the highlight of an annual ’worm gruntin’ festival’ in Sopchoppy, FL. Vermicomposting is the practice of using earthworms, primarily epigeic species, to process organic wastes into useful castings. This is useful for reduction of animal (manure) waste, human food waste, yard waste, and paper/cardboard waste. The end result is vermicompost (compost composed of the worm castings) that is increasing in popularity as a horticultural soil amendment. Often vermicomposting and vermiculture go hand-in-hand with commercial sales of both the worms and the compost produced. While not generally considered to be pests, earthworms can also have some negative economic impacts.

Recently there has been concern that earthworms in the soil surrounding airstrips might attract birds which could damage airplanes. Similarly, earthworms in lawns or golf courses attract predators such as armadillos, moles, feral swine, and some birds which can damage turf while they are excavating for worms (Figures 11, 12). Earthworms are hosts for cluster fly larvae, whose adult stages are household nuisance pests. Worm castings on golf courses (Figure 13) can damage grass, dull mower blades, and deflect golf balls. Figure 11. Armadillos can damage turf while hunting for worms and insects. Photograph by Joseph M. Schaefer , University of Florida. Figure 12. Feral swine have rooted up this golf course turf while hunting for worms, insects and other food. Photograph by John H. Foy , USGA. Figure 13. On a golf green these castings can damage turf and dull mower blades. Photograph by Eileen A. Buss , University of Florida. Management (Back to Top) Saponins are natural occurring soaps found in many plants.

Research has shown that application of saponin-containing tea seed meal to be very effective at reducing worm castings on golf course turf. Tea seed meal is a major component of at least one commercial organic turf fertilizer. Several turfgrass pesticides used for management of insects, nematodes, or fungi are known to negatively affect earthworms as well. However, no pesticides are currently labeled for use on earthworms. Beneficials in the garden: #38 Earthworms Charles Darwin wrote that ï¿½It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organized creatures.ï¿½ The humble earthworm may not be on the top list when beneficial critters are mentioned, but its contributions to a healthy soil are numerous. Earthworms are natural composters. Earthworms aid in the decomposition (recycling) of organic material. This results in improved overall soil structure, plant growth and reduced thatch buildup in lawns. Earthworms aerate and loosen the soil by digging tunnels up to 7 feet deep, bringing mineral-rich subsoil to the surface with numerous smaller organisms that contribute to the health of the soil.

Research shows that in 100 sq. ft. garden soil, earthworms may bring from 4-to-8 lbs. of dirt to the soil surface each year. The tunneling of earthworms aerates and loosens the soil allowing oxygen to penetrate deeper, which improves beneficial soil bacteria that contribute to plant health. That is why earthworms are called ï¿½natureï¿½s plough.ï¿½ Earthworms ingest soil and digest the organic matter as they tunnel, producing castings. The castings increase the nutrient level and organic level of the soil. Nitrogen, phosphorous, potassium and other nutrients are produced daily for the use of plants. The equivalent of about 1/3 lb. of top grade fertilizer is produced per worm each year. Soil rich in humus can easily support 25 worms per cubic foot. The addition of organic matter such as compost, manure, and mulches will attract earthworms by providing undecomposed litter as a food source. You may also purchase the common earthworm or "nightcrawler" (Lumbricus terrestris) and spread them around the garden a few per square foot.

Now for some other interesting facts about the humble earthworm: ï¿½ There are approximately 2,700 species of earthworms. ï¿½ The average life span of earthworms is species-dependent. Researchers have found that some species have the potential to live 4-8 years under protected growing conditionsï¿½meaning no predators and under ideal conditions. While individuals of Lumbricus terrestris can live for 6 years under ideal conditions, their lifetime is much shorter in the natural world. ï¿½ Given favorable conditions, one acre of land can contain more than a million earthworms. ï¿½ South Africa is reported to have the largest earthworm on record. It measured 22 feet from its nose to the tip of its tail. ï¿½ Most earthworms native to North America are thought to be extinct. The two most common species of earthworms in the USA are the common earthworm ("nightcrawler") and the red earthworm (Lumbricus rubellus). These earthworms were introduced from Europe during colonial times through soil in potted plants. ï¿½ The number of rings or segments of the body is species dependent.

The common earthworm has about 150 segments while red worms have approximately 95. ï¿½ Earthworms are hermaphroditic (each individual possesses both male and female reproductive organs). However, earthworms are usually not self-mating. A mutual exchange of sperm occurs between two worms during mating. Beneficials in the Garden & Landscape is an Earth-KindTM program coordinated through Extension Horticulture at Texas A&M University. Earth-Kind uses research-proven techniques to provide maximum gardening and landscape enjoyment while preserving and protecting our environment. This web site is maintained by Master Gardener Laura Bellmore, under the direction of William M. Johnson, Ph.D., County Extension Agent-Horticulture & Master Gardener Program Coordinator. All digital photographs are the property of the Galveston County Master Gardener Association, Inc. (GCMGA) 2002-2015 GCMGA - All Rights Reserved. Earthwormsinfo – Everything You Need to Know About Earthworms by Admin 12 Comments Facts On Earthworms Earthworms are interesting creatures that many people take for granted.

Besides coming across some earthworms while gardening or after some heavy rain, you might not give them a second thought. So to inspire you to find earthworms interesting I have compiled some interesting facts to get you started with your love of Earthworms. Some earthworms consume their own weight in a combination of food, water and soil everyday. Earthworm On Soil Their dry body weight is two thirds protein, and they are low in cholesterol. Food they intake usually takes 24 hours to pass through their bodies and comes out in the form of vermicast-natures best soil conditioner. A worm system 1 metre long x 2 metres wide x 30 centimetres deep can cope with the average compostable household waste for a year. A well run system does not smell offensive. Up to 70% of all household waste is edible by earthworms. Earthworms- Are Interesting In a healthy farm paddock there is more weight of protein below the surface in the form of earthworms and soil organisms than there is on the hoof abound the ground. Earthworms live 2 to 3 years under favourable conditions, but healthy worms up to 15 years old have been recorded.

Of the 8000 worm breeds in the world, 2500 to 3000 are earthworms. the balance live in water. These figures do not include parasitic worms found in the intestines of animals. Earthworms have been around for 600 million years. Earthworms only mate with worms of the same species. Worm eggs-capsules- can survive drought and cold winters, provided they are deep enough in the soil or it is well mulched. Earthworms detest sunlight- two or more hours exposure to sunlight will kill them. Cut a earthworm in half and it generally dies. You don’t get two worms. Sometimes if the cut is far enough back, the worm will grow a new tail. Earthworms are hermaphrodites- each worm is both male and female. Mature worms can fertilise or be fertilised. In some cases they may do with out a partner and self fertilise.

Worms are subject to so few diseases that you can virtually say they catch none at all, and for very good reason,the bacteria fostered in their gut and excreted with their castings are benevolent, and produced in such overwhelming numbers that disease-producing bacteria can not survive. Earthworms-Natures Friends In 1881, Charles Darwin wrote about worms: “Of all animals, few have contributed so much to the development of the world, as we know it, as these lowly creatures.” Earthworms contribute to the provision of productive soil by constantly recycling nature’s wastes and renewing soil fertility, centuary after century. Healthy soil contains healthy earthworms and other soil life. Earthworms contribute to soil health and you will find your best worms in healthy pasture, cropland and gardens. Earthworms improve the mechanical structure of soil by opening channels through which water, air and roots can travel to more easily assisting plant growth. Earthworms redistribute nutrients throughout the soil when they feed and excrete at different depths adding to soil life and plant health. It has been estimated that nearly every particle of healthy top soil on earth has passed through earthworms at one stage or another.

Different species of earthworms burrow at different depths. Their burrow range from the surface to, in some deep soils, over two metres deep. They can cross like highway intersections and can range from 1mm to 10mm wide. Some are vertical and some are horizontal. Some are more or less permanent and others are made as the need arises. There can even be small nesting chambers. These burrows allow infiltration of surface water and air to lower depths. Earthworm activity can increase soil water holding capacity and availability to plants by up to nearly 40%. So burrows from earthworms should have a significant impact on lowering water tables and reducing salinity processes. They provide paths for root systems to penetrate. The air in burrows is more humid than surface air. The number and length of burrows increases as more food is available. The earthworm casts can contain a blend of sands, clays and organic matter thus increasing soil strength. Earthworms avoid soil with coarse abrasive structures. The also dislike clays in high rainfall areas which are low in oxygen. This can be changed by the incorporation of humus. In general earthworms found near the surface are redder in colour.

Earthworms And Biological Composition Earthworms are associated with increased soil micro fauna activity. A main function of the earthworm is to redistribute organic matter throughout the soil by consuming, breaking down and excreting surface litter and soil particles, dead roots and soil organisms, and by dying. The microbes ingested by the earthworms multiply in the humid conditions of the worms interior and the slime on burrow walls, and the worm casts. The microbes convert the excreted materials into collodial humus upon which plants feed for healthy nutrients. In the right conditions of temperature and moisture levels earthworms will consume every piece of organic materials. Their population builds to the level of food supply. Some earthworms drag surface litter underground for decomposition and later consumption. Dung of grazing animals is a earthworm delicacy which will be consumed and mixed in the soil layers after the dung has aged. Bacteria levels in earthworms inhabited soil can build up to 100 times that of the population in surrounding soils. Soil bacterias and other mico organisms both help predigest earthworm food and benefit from worm excretia. The biomass in increased enormously and throughout different soil horizons.

There are about 1000 times more bacteria in the worms gut than in the surrounding soil. This could explain the dramatic increase of plant nutrient amino acid in worm populated soils and even B group vitamin So as you can see there are huge benefits to getting to know your friendly earthworm and the help they can do to our ever increasingly fragile environment, who knows, the answer to global warming could be earthworms. 7 Gender-Altering Animals – National Geographic Society (blogs) From the theater of ancient Greece to talent show TV , humans have a long and storied history of dressing up as the opposite sex. But we’re not the only animal that’s good at gender alteration. We recently told you about female market squid who flash fake testes , probably to put the kibosh on unwanted male attention. Here are seven creatures who are great at pulling a sexual switcheroo. Cuttlefish Admit it: you alter your demeanor, a lot or a little, depending on who you’re with. Just about all of us do it. You’re just not as literal about it as a cuttlefish. Male mourning cuttlefish actually show a different side of themselves depending on the company they’re with, especially if that company is mixed.

A study out of Macquarie University in Sydney found that males can split themselves down the middle, appearing to be male on one side and female on the other. A male in between another male and a female will show his true male appearance to the female to flirt with her, while showing female colors to the male. That other male thinks he’s seeing two ladies (and no rival) and won’t realize that a budding romance is happening right in front of him. Mr. Roper thinks something funny is going on here but has decided not to get involved. Garter Snakes Of all the animal romance rituals, the snake mating ball is certainly one of the most visually arresting , if not downright orgiastic-looking. Guaranteed to give the ophidiophobic a few nightmares, it’s also a squirmy stage for some clever sexual charades. Red-sided garter snakes in a mating ball in Manitoba, Canada. Photograph by Norbert Rosing, National Geographic In Manitoba, Canada, which has the highest concentration of garter snakes in the world , males emerge from hibernation slowly and groggily after eight months in the chilly ground. Pokey they may be, but they’re still on high alert for females to mate with.

Some males, though, mimic female behavior at this time. Researchers think that’s because females have a couple of survival advantages . When females emerge, they are quickly mobbed by male suitors, as are the female-mimicking “she-males.” The snakes at the center of mating balls are protected from predators (birds seek out the groggy males). Plus, all that transferred body heat allows the she-males to warm up more quickly and become fleeter of foot — well, maybe not foot– to avoid becoming lunch. Snake in the grass? Perhaps. But one that lives to slither another day. Spotted Hyena It’s not just the males of the animal kingdom that adopt opposite sex traits. Female spotted hyenas are socially dominant, larger, and more aggressive than the males. Spotted hyenas in Masai Mara National Reserve, Kenya. Frans Lanting, National Geographic But it’s not only their behavior that’s masculine. Their clitoris is so enlarged it’s often referred to as a pseudo penis . It’s capable of erection, and the female has sex, urinates, and gives birth through it. Females also have a structure that looks remarkably like a scrotum.

Even close up , it can be hard to distinguish a female from a male. There are theories but no definitive reason for the female hyena’s pseudo penis. “OMG, cool!” probably doesn’t count. African Bat Bug The African bat bug sucks the blood of bats (and sometimes bites humans). Cool enough, but even more intriguing, bat bugs have a serious game of strategy going on around their safety and sexual identity . Like bedbugs, bat bugs practice “ traumatic insemination ,” in which males stab females in the abdomen with needle-like penises and inject sperm directly into the bloodstream, which can harm the female. Males sometimes do this to each other as well. To protect themselves, females developed paragenitals, a funnel-like genital opening that guides the penis to an area filled with immune cells. Males, then, developed their own version of these paragenitals. Then the females started imitating the more successful male imitations of the female paragenitals. (See pictures: “‘Torture’ Phalluses Give Beetles Breeding Boost.” ) Females imitating males imitating females sounds like it could get seriously confusing. It calls to mind Dr.

Seuss’ Sneetches , who changed their appearance so often they couldn’t tell “which one was what one or what one was who.” But it can’t be too perplexing: The bat bugs continue to reproduce. Anemonefish, Parrotfish, and Hawkfish Some animals don’t just appear to change genders—they actually turn into the opposite sex. Clown anemonefish all start out as male. If the female dies, the dominant male can change sex and become female. Another male will become the dominant male . A stoplight parrotfish swims in Hol Chan Marine Reserve, Belize. Photograph by Brian Skerry, National Geographic Parrotfish start out as male or female but have sex organs of both sexes; they are protogynous hermaphrodites , meaning they can change from female to male. Some females will become supermales: larger males with brilliant, lively coloring. Hawkfish in the wild have been shown to be capable of “bi-directional” sex change, going from female to male and back again. Kind of poetic that the ocean is home to such elegant gender fluidity. Follow Liz Langley on Facebook and Twitter . Keywords

Question: What name is given to creatures such as earthworms which are both male and female?
Answer: Hermaphrodites