WormWatch - Anatomy - (EXT)

This article is extracted from Worm Watch

http://www.plantwatch.ca/english/wormwatch/about/anatomy.html

Anatomy
Earthworms are invertebrates, which means they have no back bone (unlike snakes, which do have a back bone). Earthworms are annelids and are members of the class Oligochaeta, because they crawl using circular and longitudinal muscles which are located under the epidermis. Each segment also has bristle like setae which help to anchor their segments as they crawl. Unlike humans, earthworms do not have a well developed respiratory system. Instead of lungs, they breathe through their skin which needs to stay moist for breathing.

Earthworms are annelids, which means their bodies are segmented. Earthworms have bilateral symmetry, which means if you cut an earthworm down centre, you would find that the left and right sides the its body are identical (mirror images of each other).

The first segment is specially named the peristomium and contains the mouth. There is a small tongue-like lobe just above the mouth called the prostomium. The prostomium is used by the earthworm to “see” its environment - as earthworms have no eyes, ears, nose or hands, it depends on the prostomium and skin to help it feel its way through the soil. As the earthworm tunnels through the soil, it excretes mucus from its body. This mucus reacts with the soil of the tunnel walls and forms a type of cement which makes the tunnel walls stable so that the tunnel can be reused.

About one third of the way down the earthworm (from the head) is the clitellum. The clitellum is a swelling of the skin and can only be seen in earthworms that are ready to reproduce. It may be white, orange-red or reddish-brown in colour. Earthworms are ready to mate when their clitellum is orange. Most of the material secreted to form earthworm cocoons is produced within the clitellum. The number of the segments to where the clitellum begins and the number of segments that make up the clitellum are important for identifying earthworms.
The very last segment is called the periproct and contains the anus.

Except for the first and last segment all the other segments have eight setae located around each segment. The setae look like small bristles sticking out of the earthworm’s skin. The setae can be retracted and are for moving through the soil. The bristle-like setae anchor the segments as they crawl.

Anatomy of an earthworm

How to identify different earthworms. The number of segments from the peristomium to the clitellum and the number of segments which make up the clitellum are species specific in earthworms. This means that if two earthworms have different numbers of segments to the start of the clitellum, they are different earthworm species . In Canada, there are three families of earthworms represented: Lumbricidae, Acanthodrilidae and the Sparganophilidae. There are some species of earthworms that are native to North America and Canada: Aporrectodea bowcrowensis, Bimastos lawrenceae, Arctiostrotus perrieri, Arctiostrotus vancouverensis, Toutellus oregonensis and Sparganophilus eiseni. Currently, 25 different earthworm species have been found and identified in Canada. Perhaps with your help we can find more!

Earthworm cocoon.

How to tell juveniles from adults. Those earthworms without genital markings such as the clitellum, tubercula pubertatis (see figure 1), or genital tumescence are juveniles. This stage of the life cycle is located between the hatchling phase and the appearance of genital markings (adult stage).

Aestivating earthworm.

Other stages in the life of an earthworm. Earthworms reproduce by laying a cocoon, a sac that contains the earthworm’s eggs. The cocoon is formed at the clitellum, and then travels from the clitellum to the head. Here it slides off the earthworm’s body and is deposited into the soil.

Earthworms can enter into periods of inactivity, or dormancy, as the result of unfavourable conditions (e.g. dry periods). This is known as aestivation. During aestivation, the earthworm curls up into a knot and becomes quite pink.

WormWatch - Ecology Reproduction (EXT)

This article was extracted from Worm Watch

http://www.plantwatch.ca/english/wormwatch/about/ecology.html


Ecology - Reproduction

How does an earthworm eat?

Earthworms eat by pulling food into their mouth with their prostomium combined with the muscular pharynx which creates a very high suction (like a vacuum). The food is stored in the crop and then ground up into small digestible pieces in the gizzard. Earthworms need a gizzard because they do not have any teeth. The nutrients are absorbed into the body in the small intestine.

Earthworms probably feed while they are moving. They are not picky eaters as they will eat all sorts of dead things such as decaying plant and animal matter. They consume a great deal of matter in a short period of time - they can produce their own weight in castings (worm dung) every 24 hours!

View of the digestive system of an earthworm.

Where do earthworms live?

Earthworms are found all over the world. Australia, the Sahara Desert, Greenland and China are among only a few countries that have their own distinct indigenous species. Although several species live in various horizons (layers) of the soil or in the surface layer, others can be found in rotting logs, in the axils of tree branches (the upper angle between the branch and the trunk, sometimes up to 10 m above ground) or along the moist soil surrounding bodies of water (lakes, rivers, springs, ponds).

Despite this wide variety of habitats, there are still certain environmental conditions which must be maintained for an earthworm to survive. For example, all earthworms need an adequate food supply to be close at hand. Earthworms generally remain close to their food supply. Since earthworms breath through their skin (they have no lungs), it is important that their environment is moist to allow for respiration. Earthworms release internal fluids (like perspiration) which traps the dissolved oxygen. Too much moisture (heavy rainfall) however takes the place of the valuable oxygen dissolved in the soil (also needed for survival), which may cause the earthworms to crawl to the soil surface. Here at the soil surface, earthworms will be exposed to ultra-violet radiation (sunlight) which is lethal to earthworms in a short period of time.

Earthworms are light sensitive and prefer moist slightly warm soil to grow and reproduce. Since earthworms live and travel around in the soil they form burrows as they move. Some species make deep vertical burrows. These earthworms are anecic species. Other species burrow continuously to form a network of channels -some vertical and some horizontal in the rhizosphere and are called endogeic species. Some earthworm species are not strong burrowers and live in the uppermost layer of soil in the litter layer. These earthworms are called epigeic species and they form shallow vertical burrows where they temporarily escape from drought, heat and disturbances.

Though small, earthworms are fighters. They have developed certain survival strategies which help them cope with nasty environmental conditions. When the weather gets cold and the soil starts to freeze, earthworms move deeper down and overwinter in a state called aestivation. To aestivate, the earthworm generates a natural antifreeze and then curls up in a little knot. Earthworms also aestivate when conditions become dry or hot.

How do earthworms reproduce?

Of all the soil organisms, the earthworm has by far one of the most unique modes of reproduction. Earthworms are hermaphrodites, which means they have both male and female reproductive organs. This brings us to one of the oldest myths about worms: that earthworms can fertilise themselves. Though some earthworms can fertilise themselves (parthenogenesis), this is not the norm. Most earthworms require a mate of the same species to reproduce.

Reproduction between two Earthworms

You can tell when an earthworm is ready to mate because its’ clitellum will change colour from pinkish to red-orange. The two earthworms line up in a head to tail fashion and exchange spermatozoa (sperm). The sperm is stored in the spermathecae. Both worms do this at the same time. A slime tube then forms around the clitellum, which dries and fills with a fluid called albumin. The earthworm then wiggles out of the tube head first. While the tube passes from the clitellum to the prostomium, it passes over the female pore which deposits ovum (eggs) into the capsule, followed by the spermatheca pore (male pore) which releases the stored spermatozoa. Some earthworms mate on the soil surface and some earthworms mate in the soil. Given the dark soil environment, we think that earthworms produce a pheromone (chemical) that signals other earthworms in the area that it is ready to reproduce.

What do earthworms do?

Life on this planet would be a lot different without our little friends from down under. The quality of our soil depends heavily on the livelihood of earthworms. In the long run, healthy high quality soils will be the key to a sustainable environment and thus ourselves. The biological, chemical and physical properties of soil are essential for plant growth, regulating and partitioning of surface to ground water, and buffering, detoxifying and scrubbing of hazardous chemicals

In actuality, the soil is a reservoir of biological diversity that likely exceeds that of aboveground ecosystems.

The effects of soil quality on soil productivity.

Earthworms have some unique functions in the soil. Their large burrows allow rain water easy entry into the soil, increasing the infiltration rate of soils. This prevents water erosion and lets water enter the rooting zone where it can be used by plants. Their burrows also allow roots to move easily through the soil into new spaces. Soil that has been worked by earthworms has a stable crumb-like structure which is less likely to blow away in the wind.

Earthworms are considered very important in soil organic matter cycling. Certain species are responsible for burying surface residue, while other species are actively involved in the decomposition process, making available important nutrients for other living organisms in the soil - like plants.

The effects of soil productivity on food quality, health and environmental quality.

Earthworms have some negative traits as well, in certain areas introduced species have created competition for native earthworms. This makes it very difficult for native species to live successfully and even survive, native species frequently exist in small isolated areas. Many of the earthworms we think as common have been introduced from Europe. This is not necessarily a bad practice but has created some problems. An example is the middens associated with Lumbricus terrestris, in Western Canada were soils are dominated by calcareous parent material the deep burrowing Lumbricus terrestris creates middens of concrete. Their burrowing exposes the hard subsoil to drying and wetting cycles which makes this material very hard and difficult to manage in gardens, golf courses and lawns.

Fertilizer - Feeding the Soil

by Richard Chew

I use a few types of fertiliser for my roses and garden plants, to suit various situation.


The most common ones that I use is chicken manure (organic fertiliser), which is also the most economical ones. I would apply it every 2 weeks at my roses.



As I feed the plants I will observe the condition of the soil. I look for traces of earth worms, as this is the best indicator of healthy soil. I will also check the soil texture because the soil texture can give you some indication of amount decomposed matter contained in the soil. And when watering I look for bubbles because this indicates that the soil is well aerated and also good indication that the worms are actively working (tunnelling) beneath the soil.




Another good indicator is after you feed the soil, the organic fertiliser tend to decompose rather quicker if your soil is riched with earth worms.




If these signs are not present, the soil should look either dry and coarse or the other extreme would be wet and muddy. The plant may look sluggish and growth seemed stunted. In this situation, I will change my feeding pattern. I will use water soluble type.

The reason I revert to water soluble is because this would be the most effective short term remedy to restore the plant. The water soluble type will directly feed into the plants' roots thus gives you ample time to rectify the soil condition. I would use N20-P20-K20 and one that will not "burn" the roots.

For dry and coarse soil, I would water it with water soluble fertiliser more frequently. One teaspoon per 4 litre of water. I will feed probably 2 to 3 times a week.


If the soil is wet and muddy, usually this happens after days of consecutive heavy rain, I would daily fork the soil to ensure proper drainage. And monitor the soil condition for a week or two, if no improvement I will replaced the soil with increased mixture of charcoal granule. The purpose of mixing charcoal is to improve the water drainage. It is important that the soil is well aerated and right amount of moist, otherwise the leaves will turn yellow and spotted. This is sign of over watering.


While carrying out these contingencies, I will feed the soil with organic manure and add some earth worms to cultivate vermicomposting that naturally converts organic matter into useful nutrients for the plants. Check the table.

While it would take some time for the organic manure to decompose, I will continue to use water soluble fertilizer until the rose plant grow some new shoots and more healthy leaves. This is clear sign that the rose plant is restored and growing healthily. As the soil gradually improves, I will gradually reduce the frequency of the water soluble type and revert to vermicomposting process to feed the rose plant.



I won't say what I suggested will surely guarantee results but it would definitely increased the chances of success.

If I want to get some extra blooms, I will use fertiliser formulated for flowering. The most common combination is 18N-24P-18K and will use water soluble type to avoid burning the roots. It is not good to use this too frequently, as it would "exhaust" the plants, especially young ones. It is fine to apply on healthy rose plants with bushy leaves and healthy stems.


Read continuation in Part 2

Soil Maintenance -Why?

by Richard Chew

One of the key thing that I learned about keeping my plants healthy is knowing the right way to maintain a healthy soil.

Yes I am not kidding. I am talking about Soil Maintenance. I don't think I have ever come across any such term in any gardening book. Anyhow it is no harm inventing one here in my blog. What I am going to present here is something that probably been mentioned before, but I do believe the way I present it will help many beginners to think logically and help make better decisions in maintaining and growing healthy garden plants successfully.

I struggled quite a bit in keeping my plants alive in my first 2 years of gardening experience. I did all that I learned in the gardening manual/ guide and researched many types of garden plants, but somehow I knew I was missing something. I am not saying the manual tips doesn't work. It is just that I had trouble getting the desired results. I knew some of the causes were due to wrong decisions being made. And the sad part is that I can not seemed to figure out what I did wrong or what I failed to do. It really seemed irregardless what I do or not do the results seemed to destined to failure.


I almost gave up and thought that perhaps I don't have what it takes to develop a green thumb. And I suppose just like many people, the thoughts of throwing the towel and staying in the safe zone seemed to be the most viable option. Perhaps by remaining with 'easy' plants then I won't face anymore disappointments.

Thankfully through these experiences, I've learned some very important lessons. I am no expert but I am convinced that what I am presenting here will help many beginners to develop better green thumb than me. I am fully convinced that to excel in gardening, the first lesson is to understand the science beneath the soil. Maintaining a good healthy soil will aid your plant to reward you with many display of blooms. Be assured of this principle. It works.

But the seed on good soil stands for those with a noble and good heart, who hear the word, retain it, and by persevering produce a crop.

Luke 8:15

In this posting, I hope to help you make the right decisions for your plants, not just to keep your favorite plants alive but also make it healthy and blossoming one.

I believe by now you will have this big question in your mind, why Soil Maintenance? Why not other tips? Why not talk about what fertilizer to use, or what soil to use, or secrets of growing roses and etc? The reason why I place a very high importance in Soil Maintenance is because our outdoor plants are exposed to external and internal factors. Knowing what happens beneath the soil will greatly impact the results of your plants.

I won't be discussing what kind of soil or what mixture of soil to use, as pre-mixed soil for gardening plants are easily sourced from many gardening stores and nurseries in Klang Valley and they are well suited for most garden plants.

Before I discuss the how to maintain the soil, let me discuss about the external and the internal factors that influences the soil condition that we to look out for and counter them immediately.



External Factors

Weather - Malaysia's weather can be very unpredictable. At certain times of the year, we do experience very extreme torrential rain, that can be quite detrimental to the plants. The continous and prolonged torrential rain will flood the soil, thus impedes its drainage and shuts out soil aeration. If the soil is left unattended, the wet condition will cause black spots at your garden plants and may invite fungal infections if the condition is not reversed. These are symptoms of excessive watering. Another undesired outcome is that excessive water will flushed and forced out many friendly critters that benefits the garden plants, such as earth worms.



Fertiliser - The choice of fertilizer is another external factor. There are many types of fertilizer available in the market, and it is always the case that each manufacturer will say that they are better than the other. Or perhaps you are currently using a fertiliser that was recommended by your most trusted garden nursery store. Don't be too overly concerned because it is not always one size fits all. You will most likely need a few types of fertiliser to achieve good results.


Just for illustration purpose, Vitamin C is good for health, but Vitamin C by itself doesn't guarantee us good health all the time. There are also other essential vitamins and minerals that our body needs to fight off other health challenges. It is definitely not one size fits all.


Internal Factors

Allies to Good Soil - Earth worms are actually the best allies for good healthy soil. Yes, it is those wriggling 'irky' creatures that nourishes your plants' roots by converting organic matter to essential nutrients. Another benefit is that earth worms naturally tunnels the soil thus improves drainage and also promotes better aeration in the roots.


When your plants are fed with organic fertiliser, it is these critters that converts them into useful minerals. The increased population of earth worms in your soil are good indication of healthy soil.


Another allies for good soil are microbes, the micro organism that lives in the soil. These microbes also converts organic matters into nutrients to nourish the roots. They are most active at warm temperature range usually morning . Plants grow better under the morning sun as it is at this period that these bacterias are most active at work and will cease activities when it exceeds the working temperature range.

Understanding these factors and detecting them correctly, will help to make the right decision in maintaining your soil. The next posting, I will share what we can do to maintain healthy soil.

About this Blogger

Hi... my name is Richard Chew. I didn't really started off gardening because I love gardening nor was I an expert in plant biology. I am just like any ordinary guy.

I guess I started gardening because I really like nature and greens. I begun this garden project when I moved to a townhouse in Kota Kemuning in 2006. Though the townhouse is designed for compact living space, it came with a 200 sqf garden space.

It is not a very big space but adequate to start off small garden project. I decided to make full use of the space by filling it up with greens. I have tried many floral plants, however the best experiences are with roses.

My initial experience wasn't a bed of roses. There were quite a number of failures along the way. Therefore I thought why not start a blog, to keep a journal of ongoings in my project.

I hope as you visit this blog, you will find many good information that is useful at your garden. I put lots of effort in posting good research works from public site on plant psychology. Hope by equiping with a little more science we get to be more appreciative of God's creation.

I will make time to share my experiences and my frustrations in cultivating rose. I will also be delighted to hear your good and bad experiences that you may encountered in starting a garden.

Pls feel free to visit my blog. Post as many comments or questions that you wish. You may also send me some nice pictures of your garden, I would be happy to post it in my blog to share your work with others.

Or you may email me at cshaw@pc.jaring.my


Pls visit my first posting, and happy exploring.