Bio E-learning (Jin Kai)

Many people have wondered how snails reproduce and grow into adult snails. Some think is by sexual reproduction and some think asexual reproduction. Let’s start the journey into the snail’s world.
Snails will be able to reproduce differently than almost any other type of creatures because of their species and their make-up. This begins with the build that all snails have. Snails are considered to be hermaphrodites, which mean that every snail will have both male and female reproductive organs. This is especially consistent among land snails and most marine snails. These two types of snails still have a separate male and female species are Apple Snails and Periwinkles.
All snails will be considered sexually mature when they are in age of one year old. This is because the life span of most species does not last for more than five to seven years, allowing for a faster growth rate of the species. The make-up of the snails will include their reproductive organs on the side of their body. This is close to the top of their body as well, allowing for easier abilities to mate and grow the baby snails.
The mating practices of snails are the one that allows for new snails to be brought into the dirt and water at a consistent rate. Snails will go through a complete mating ritual with each other, usually which will communicate to the other snail for an average of two to twelve hours. At the end of this ritual, the pair will fertilize the eggs in the other. It is known that a snail can carry up to 100 eggs at a time.
When the eggs are fertilized, they will go through a process of growth inside the snail. This begins with the fertilization moving the snails into a specific amount of development inside the embryo. This takes place with the snails laying eggs and burying them into a cool place in order to grow. For land snails, they will be buried underneath the dirt in order to be cared for. With marine snails, the eggs will be placed next to a solid area, such as a rock. This will allow the eggs to stay in the same place and develop without being harmed.
It will typically take a snail egg two to four weeks in order to develop. As soon as they hatch, they will immediately move into a survival mode. This is because their shells will still be in a weak form. Their reaction is to find calcium as soon as they hatch by either eating their own egg or eating other eggs in order to get the extra nutrients. It will take around three months for the snails to completely form. While this takes place, they will stay in a nest that has been built for them, with the transformations being seen through a change in colour, from a clear colour into a blue then into the adult form that is representative of the species. After the snails are completely developed, they will detach from their parents and move into a different shell.
The mating procedures of snails are one that moves through a specific process that helps the species to grow and survive in their respectable areas. From the beginnings of sexual maturity to finding the rate mate to the hatching of the eggs, is a specific way in which the snails are able to move into a world of growing a larger snail family.
Reflections
I learnt that most of the snails’ species have both male and female reproductive organs while some have separate male and female reproductive organs.
I also learnt snails need to undergo many procedures during fertilisation before it born and after they hatched; they immediately went to find nutrients for its survival independently.
I was fascinated by the nature of snails and their reproductive organs (both male and female). Actually I did not know snails are hermaphrodites but once I learnt they have both male and female reproductive organs, I was amazed.
It was unimaginable that one small snail can have many interesting facts about them which many people did not considered.

Bio E-learning (mervyn)

here is my post for the assignment for Biology,

mervyn here, i do wonder how snails reproduce but i have never actually go into the subject and dig for information but when given this assignment, i have actually found out that most snails are actually hermaphrodites i dont know how to pronounce hermaphrodites but i understand that hermaphrodites have both female and male sexual organs.

snails are hermaphrodites but they do not fertilize themselves but instead they find mates which they will encounter throughout their lives, there was one site where they said that snails mate with every snails of their kind which they meet and that both snails will be fertilized. i also noticed a paragraph which they state that only one or two species of snails have only one sexual organ, the Pomacea Bridgesii for example, they are not asexual where a male and female are requird for fertilization, the male would place his sperm in the female shell and would continue to hold on onto the female's snail shell. the sperm would last a few weeks in the female snails shell.

its a wonder how a snail would live everyday. the infomation below is the combination of two websites information. i have learnt many facts about the snails and i wnder if there would be any other animals which will be as mysterious as the snails.



http://www.snail-world.com/How-do-Snails-Reproduce.html
http://wiki.answers.com/Q/How_do_snails_reproduce
http://answers.yahoo.com/question/index?qid=20061010073700AAxifWT
and theres one more but the website wasn't found.









Snail reproduction is a curious tale. Snails are hermaphrodites, but although individuals contain both male and female sex organs, they do not self-fertilize. The two to six hour marathon session that is snail copulation is actually an exchange of sperm between two individuals, combined with plenty of rubbing, biting and 'eye-stalk' waving. Individuals use the received sperm to fertilize their own eggs — a process that is necessary to maintain genetic diversity in the population.

What makes some snail species particularly interesting to Dr. Chase is their use of 'love darts' during copulation. About one third of snail species manufacture hard, sharp darts which they 'fire' at the object of their affections (i.e. other snails).

"The love dart phenomenon has been documented in the literature as far back as the mid-17th century," noted Dr. Chase. "Love dart snails were known to the ancient Greeks, and it wouldn't be surprising to find that they influenced the creation of the cupid myth".

Dr. Chase became intrigued with snails' 'love darts.'

"It was incorrectly believed that these darts were a nuptial gift of calcium —a major constituent of snail shells—from one snail to another. Like a bunch of flowers or a box of chocolates in humans," explained Dr. Chase. "Another belief was that the dart was intended to arouse the receiver and indicate the shooters readiness to mate."

Research conducted by Dr. Chase has uncovered the real reason for dart shooting in snails, and the truth is much more sinister than previously thought.

The answer lies in Darwin's theory of sexual selection. Basically, snails want to reproduce as much as possible. Snails that have a way of ensuring that their sperm, rather than another's, is used to fertilize eggs will therefore sire more offspring. This is known as sperm competition



All hermaphroditic snails can lay eggs. Tim can "mate" with himself and thus only one can reproduce in an aquarium or pond. he also breeds sexually as often as possible. Most snails lay eggs but some, like the trapdoor snail, give live birth. Trapdoor snails and a few other species of snails (apple, golden inca, four horned, etc.) are not hermaphrodites. They can only reproduce sexually.
Underwater Snail Eggs: For those snails that lay eggs in the water, snail eggs look like little jely blobs stuck on hard surfaces and plants. Favorite places to lay eggs include aquarium glass, clay pots, bricks, large plant leaves, and almost anywhere sturdy enough. The eggs begin clear but soon get a dark spot which grows larger as the snails grow. Unlike fish eggs, you will not see two large eyes looking up to you. After about 3-6 weeks depending on species and temperature, the babies emerge. They are quite vulnerable to being eaten at that time. There is nothing special to be done for their care aside from providing foods their parents like if algae and plants are scarce. People often add snail eggs to aquarium and ponds without knowing it as the eggs come hitching rides on live plants or even inert materials moved from another aquarium or pond. Rarely, eggs may be infertile or die. In that case, they will turn white as fungus attacks them. Healthy snail eggs are clear with a dot inside.
Above Water Snail Eggs: Apple snails lay eggs above the water line, usually on plants but in an aquarium, they often lay eggs on the lid. Apple snail eggs are yellow or pink. They need to stay damp but not submerged in order to develop.

Mystery Snails are most likely a species called Pomacea Bridgesii. These are freshwater aquatic snails which lay eggs ABOVE the water.
Pomacea snails are MALE and FEMALE. They are NOT aesexual. So you will have to have 1 male and 1 female, at least, before you see breeding and egg laying.
The male will climb onto the females shell, slightly over to one side, his penis looks like a flat white tube (similar to his breathing siphon, but shorter and fatter) and he will insert it into the female's shell and up into her body.
She will usually continue about her life, walking around the tank while the male continues his deed riding on her shell.
Females may or may not lay eggs after the male breeds her. Pomacea species snails can carry sperm in their bodies for many weeks.
When ready to lay eggs, the female will climb up the side of the aquarium wall and leave the water. She will continue up as far as she can go, or about 3-4 inches.. depending on how much room she has. If you do not have a lid on your aquarium, she can and most likely will, fall out of the tank.
My snails enjoy laying their eggs near the light bulbs in the light canopy. The eggs are a small hard mass, usually pale creme in color. Though some other Pomacea species lay bright red, dark pink, lime green, and solid white eggs.
If eggs are kept warm and moist, baby snails will hatch on their own in about 2-3 weeks. Sooner if they are kept warmer. Baby snails will eat their way out of their egg cluster and drop down into the water. They look just like their parents, only tiny. It takes some color-varieties a few weeks before they show their adult coloring, but wild- and golden-colored babies look pretty much like their parents from day 1.
Sometimes the eggs won't hatch. This is usually due to lack of humidity, though sometimes a virgin snail can lay eggs which are infertile. Usually if you leave the eggs alone, and let nature take it's course, you will soon have alot of babies in your tank.
One single egg clutch can hold anywhere from 20 to 2,000 eggs depending on the species. Asolene Spixi, which is a rare forum of apple snail, usually lay egg clusters that only have 15-20 eggs. Pomacea Canaliculata can lay clusters with up to 2,000 eggs.

How Snail Reproduce?(Nas)

If you are entering into the wild world of snails, you will also begin to notice that the way in which they are built has allowed for their survival through centuries. One of the ways in which this has continued to build is through the abilities to reproduce by these creatures. The different features and ways in which they can do this also provides them with the capacity to keep slugging on the land.

Reproductive Make-up of Snails

Snails will be able to reproduce differently than almost any other type of creature because of their species and their make-up. This begins with the build that all snails have. Snails are considered to be hermaphrodites. This means that every snail will have both male and female reproductive organs. This is especially consistent among land snails and most marine snails. The only snails that have not adapted this attribute is some freshwater and marine species, specifically including Apple Snails and periwinkles. These two types of snails still have a separate male and female species.



All snails will be considered sexually mature by the time they are one year old. This is because the life span of most species does not last for more than five to seven years, allowing for a faster growth rate of the species. The make-up of the snails will include their reproductive organs on the side of their body. This is close to the top of their body as well, allowing for easier abilities to mate and to grow the baby snails.


Growing Into Baby Snails

The mating practices of snails is one that allows for new snails to be brought into the dirt and water at a consistent rate. Snails will go through a complete mating ritual with each other, usually which will communicate to the other snail for an average of two to twelve hours. At the end of this ritual, the pair will fertilize the eggs in the other. It is known that a snail can carry up to 100 eggs at a time.

When the eggs are fertilized, they will go through a process of growth inside the snail. This begins with the fertilization moving the snails into a specific amount of development inside the embryo. This takes place with the snails laying eggs and burying them into a cool place in order to develop. For land snails, they will be buried underneath the dirt in order to be cared for. With marine snails, the eggs will be placed next to a solid area, such as a rock. This will allow the eggs to stay in the same place and develop without being harmed.

It will typically take a snail egg two to four weeks in order to develop. As soon as they hatch, they will immediately move into a survival mode. This is because their shells will still be in a weak form. Their reaction is to find calcium as soon as they hatch by either eating their own egg or eating other eggs in order to get the extra nutrients. It will take around three months for the snails to completely form. While this takes place, they will stay in a nest that has been built for them, with the transformations being seen through a change in color, from a clear color into a blue then into the adult form that is representative of the species. After the snails are completely developed, they will detach from their parents and move into a different shell.

The mating procedures of snails is one that moves through a specific process that helps the species to grow and survive in their respectable areas. From the beginnings of sexual maturity to finding the rate mate to the hatching of the eggs, is a specific way in which the snails are able to move into a world of growing a larger snail family.




My View:
I never knew that the reproduction Snails undergo that kind of process. I am dumbfounded by my new discovery. Not really discovery, I just research about it. I cannot insinuate Ms Nada of being lazy, because I myself was interested when I saw the elearning assignment. I said to myself, "Ya huh. How do they reproduce or even mate for that matter?" The question brought up more questions and more questions.

For instance, do bugs have a heart or even a brain in their tiny bodies and head respectively, how do different bugs mate, do bugs undergo excretion and how, and well many more. This question generally stimulates me to react by thinking of more and more questions related to bugs. I myself did not even know that snails had a small lifespan or even had their own ritual for mating. I have really learnt tons of new information. After doing the elearning, I have a sudden interest of animals and how they live their lives. In addition, there are still some animals in the planet yet to be discovered as well the world is big place. Thus, some parts of Earth are still not studied. The scientist claim that some places are too dangerous to go to.

Thus, I am not acting like a fool, but believing maybe there are sasquaches, bigfoot and other completely wierd animal in this world. There is a possibility that such animal exists. Hence, I would like to thank Ms Nada for giving the question, as it truly opened a new interest in me.

Reflection

Mervyn: Botanic gardens Singapore is a wonderful place, fresh air ,beautiful plants and the colourful scenery. The best place that my group ever been to was the cool house where species of plant which lives in a cold environment lives... We've had seen colourful and mystical flowers in the mist house. The only sad feelings I had was the sight of only one Vanda miss Joaquin plant in the garden as the
others were being trimmed...
There is a saying:
There is dignity in suffering; nobility in pain; but failure is a salted wound, that burns and burns again. it shows the perseverance of oneself being one who cant do one does.
This was a great experience for the past few years as the botanic gardens has had changed through the years. Thank you for this wonderful trip.

Jin Kai: Botanical Gardens is the most fantastic nature reserve in Singapore. When I reached there in the morning, I could smell the fresh air and the morning dew. When I stroll past the swan lake, it’s the most beautiful scenery I ever seen. I saw a variety of flowers. Different colours and structures of the flowers makes the Botanical Garden more colourful. I liked the cool house because the place was remarkably cold and had a small waterfall to top it all off.

I was fascinated by the names of different species of flowers. Some flowers look alike in appearance but they were actually different species. It was a pity I didn't see our national flower Vanda Miss Joaquin as it had not bloom. I enjoyed taking photos of the flowers to keep as a mementos. I wish I can visit the Botanical Gardens again . Thank You!

Nashrulhaq(NasBregas): Botanical Gardens is truly a wonderous and intoxicating place. I was in an exuberant mood when we left school because I forgot to bring my tie and thus, lucky to escape from a scolding. It was an experience that had its lows and highs. Like when I was kicked out from my previous group without knowing it. Behind my calm facade, I felt betrayed and disheartened. Another is that we had to keep walking and walking in cold sweat as we headed to different locations, one after the other. The food price was proposterous and ludacris as it was too expensive that I was not able to buy anything. I enjoyed seeing all the flowers and I even saw with my own eyes a gigantic spider web. I felt like Indiana Jones. Some flowers were also fascinating and intriguing to look at. Some were beautiful while some were awkward. It was disappointing that I was not able to see Singapore's National Flower though. On the other hand, I enjoyed taking photos and especially enjoyed being in the Cool Room. It was very cold in there and it felt good to cool myself down in there. I even wanted to stay in there til it was time to head back to the rendezvous point. However, the time had come and so my group and I headed back. It had a great time and so did the others. I learnt alot from this experience and hope that such activities will be planned again. If the blog is not up to standard, my group and I wish to apologize as this was our, no my first time doing this. Thank you though. Ms Nada and the school, you have made me realize the beauty of nature and I no doubt the trip has totally been an eye-opener for me. Once again, thank you!!!

Flower Parts & Function (Shorter Version)

Petal: Petals are used to attract insects into the flower, they may have guidelines on them and be scented.

Stigma: Is covered in a sticky substance that the pollen grains will adhere to.

Style: The style raises the stigma away from the Ovary to decrease the likelihood of pollen contamination. It varies in length.

Ovary: This protects the ovule and once fertilisation has taken place it will become the fruit.

Ovule: The Ovule is like the egg in animals and once fertilisation has taken place will become the seed.

Receptacle: This is the flower's attachment to the stalk and in some cases becomes part of the fruit after fertilisation e.g. strawberry.

Flower stalk: Gives support to the flower and elevates the flower for the insects.

Nectary: This is where a sugary solution called nectar is held to attract insects.

Sepal: Sepals protect the flower whilst the flower is developing from a bud.

Filament: This is the stalk of the Anther.

Anther: The Anthers contain pollen sacs. The sacs release pollen on to the outside of the anthers that brush against insects on entering the flowers. The pollen once deposited on the insect is transferred to the stigma of another flower or the same flower. The ovule is then able to be fertilised.

TAKE NOTE!!!!: This post is the same thing as Structure and Function but, it is much shorter and more straight to the point.

More Information On Flowers(Interesting!!!)

Dioecious - refers to a plant population having separate male and female plants. That is, no individual plant of the population produces both microgametophytes (pollen) and megagametophytes (ovules); individual plants are either male or female.

Androecious - plants producing male flowers only, produce pollen but no seeds, the male plants of a dioecious population.

Gynoecious - plants producing female flowers only, produces seeds but no pollen, the female of a dioecious population. In some plant populations, all individuals are gynoecious with non sexual reproduction used to produce the next generation.

Monoecious - an individual that has both male and female reproductive units (flowers, conifer cones, or functionally equivalent structures) on the same plant; from Greek for "one household". Individuals bearing separate flowers of both sexes at the same time are called simultaneously or synchronously monoecious. Individuals that bear flowers of one sex at one time are called consecutively monoecioous; plants may first have single sexed flowers and then later have flowers of the other sex. Protoandrous describes individuals that function first as males and then change to females; protogynous describes individuals that function first as females and then change to males.

Hermaphrodite - A plant that has only bisexual reproductive units (flowers, conifer cones, or functionally equivalent structures)
Subdioecious, a tendency in some dioecious populations to produce monoecious plants. The population produces normally male or female plants but some are hermaphroditic, with female plants producing some male or hermaphroditic flowers or vice versa. The condition is thought to represent a transition between hermaphroditism and dioecism.

Gynomonoecious - has both hermaphrodite and female structures.

Andromonoecious - has both hermaphrodite and male structures.

Subandroecious - plant has mostly male flowers, with a few female or hermaphrodite flowers.

Subgynoecious - plant has mostly female flowers, with a few male or hermaphrodite flowers.

Polygamy - Plants with male, female and perfect (hermaphrodite) flowers on the same plant, called trimonoecious or polygamomonoecious plants. A polygamous inflorescence has both unisexual and bisexual flowers.

Imperfect Flower
A flower that has either all male parts or all female parts, but not both in the same flower. Examples: cucumbers, pumpkin, and melons.

Perfect Flower
A flower that has both the male parts and female parts in the same flower. Examples: roses, lilies, and dandelion.

Structure and Function

The female parts of a flower consist of an ovary, which contains one or more ovules, a style and the stigma. The ovary is at the base of the flower.
From the ovary, extends a tubular structure called the style and on the top of the style is a surface receptive to pollen called the stigma.
The stigma can take many different forms, most of them designed to help trap pollen. There are many variations on this basic structural theme.
After fertilization the ovule becomes the seed and the ovary becomes the fruit.



The Male Reproductive Organ is The Stamen. The male parts of a flower consist of one or more stamens. Each stamen is made up of paired anthers (sacs containing pollen) on a filament or stalk.
The anthers are the orange/yellow structures often seen in the centre of a flower.
Pollen from the anthers of one flower is transferred to the stigma of another usually either by wind, or by animals, especially insects.

PETALS, COROLLA, SEPALS, CALYX

The reproductive structures in higher plants are contained within flowers. Flowers have more than one petal, and the flower petals are collectively called the corolla. A flower bud is protected by green leafy structures called sepals. Collectively, all of the sepals form the calyx.

The corolla or petals are often brightly coloured with markings attractive to insects. The flowers may also be scented. For instance, Honeysuckle has showy, attractive flowers which attract insects by day. However, in the dark, their colourful show is not much use, and their heady scent then helps to attract night-flying moths.

In insect-pollinated plants, there are also usually nectaries which secrete sugary nectar, located within the flower. These provide an incentive to insects to visit the flowers. In the search for nectar, the insects will often get pollen grains caught on their bodies. This may then brush off onto the stigma of the next flower visited and in this way the flowers are pollinated.

The receptacle is the place on the stem where floral organs originate and attach.

Formation of Sex Cells
The sex cells of the flowering plant are called gametes. There are both male and female gametes thus the flower undergoes sexual reproduction.



Male Gametes


Pollen Formation: Development Of A Pollen Grain Within The Pollen Sac Of An Anther: A cross section of the developing anther displays four chambers. These chambers are called pollen sacs (see upper illustration). Each pollen sac is filled with cells containing large nuclei. As the anther grows, each of these cells goes through two meiotic divisions, forming a tetrad. These cells are called microspores. Each one of these microspores eventually becomes a pollen grain. Each pollen sac is enclosed by a protective epidermis and a fibrous layer. Inside the fibrous layer is the tapetum. This is a food store and will provide energy for future cell divisions.



Each pollen grain is surrounded by a tough protective wall called an exine. This is a tough covering that allows the pollen grain to survive harsh conditions for long periods of time. The intine is another thin protective coating.First, each nucleus divides by mitosis to become two nuclei. One is the tube nucleus. The other is a generative nucleus. The wall of the cell thickens to protect the developing pollen grain. As the anther ripens, the wall between the paired pollen sacs disappears. The pollen sacs burst open and the mature pollen grains are ready for dispersal.

Development of Embryo Sacs



Each ovary contains one or more ovules. The green structure at the top of the diagram is the ovule. The integuments are the 2 walls of the ovule. There is a small opening in the walls called a micropyle. This is where the pollen tube will enter. (Will be discussed later.) The nucellus is cells that provide nutrition for the growth of the ovule. The embryo sac, also known as the megaspore, divides by meiosis to form 4 haploid cells. Three of these cells degenerate and one remains. Only one megaspore survives in each ovule. This becomes the embryo sac. The haploid nucleus of the surviving megaspore undergoes three mitotic divisions. Eight haploid nuclei are now present. Within the swollen ‘megaspore cell’ six haploid cells and two ‘polar nuclei’ are formed. The entire structure is called the embryo sac. One of the cells near to the micropyle end of the ovule is the haploid female gamete (egg cell).









The Carpel With a Mature Embryo Sac will appear as shown below:




















Individual plant sexuality

Many plants have complete flowers that have both male and female parts, others only have male or female parts and still other plants have flowers on the same plant that are a mix of male and female flowers. Some plants even have mixes that include all three types of flowers, where some flowers are only male, some are only female and some are both male and female.

A distinction needs to be made between arrangements of sexual parts and the expression of sexuality in single plants versus the larger plant population. Some plants also undergo what is called Sex-switching, like Arisaema triphyllum which express sexual differences at different stages of growth. In some arums smaller plants produce all or mostly male flowers and as plants grow larger over the years.