To be male or to be female,that is a question(part two)

Hello everyone,this week I will thoroughly introduce the phenomena of gender changing.First,after understanding what the Sequential Hermaphroditism is,you may want to ask“Why do creatures have this phenomena? ”.As the topic said,this is a good question,and I would like show some opinion of scientists to find the answer.For the first question：“Why do creatures have this phenomena?”,the public answer is that due to the low population densities,it is hard for some animals to find a partner to mate.By this way,one individual can have higher ability of reproduction.

However,this tremendous change of body cost a lot of time and energy.According to the research done by Yale University and the National Science Foundation,they found that i their theoretical models of the hermaphrodite spend 30 percent of its lifetime in the process of change sex, and still persist in a population.It shows the change of sex is in no way easy.In addition,this strategy will cause lower genetic recombination(遺傳再組合),which may lead to inbreeding depression.

After explaining the answer,It is time to see some interesting examples.This time,I choose this popular fish as our topic.

the clownfish

About its amazing strategy of reproduction,I think everyone can watch this week's video.(I think you may not want to read words now,aren't you?) 

 This is the end of this week introduction.And next week we will see that the similar phenomena happens on plants.

Video： https://www.youtube.com/watch?v=2YHB8AWnjwc

Reference：1.http://en.wikipedia.org/wiki/Amphiprioninae

2.http://www.science20.com/news_releases/sequential_hermaphroditism_some_animals_change_their_sex_why_dont_more

3.http://biology.stackexchange.com/questions/5148/why-are-not-all-species-hermaphrodites

To be male or to be female,that is a question (part one)

Hello everyone.this week I choose a special phenomena of biology as my topic─the sequential hermaphroditism,wihch means that creatures have the ability to change their gender in their lives.Easily to say,can you imagine that before 18 years old you are boys and after 18 years old,all the boys change into women?This is the phenomena of sequential hermaphroditism.Now we know what the topic means,but which creature have this extraordinary change in their life?Well,about this qustion,I'd like to use picture to answer it.

First,this phenamena is devided into 2 types─one means that animals are born male and at some point in their lifespan change sex to female,which is called the Protandrous hermaphrodites.This kind of animals include clownfish(尼莫)

and ctenophore(櫛水母)

and the other type of hermaphroditism is Protogyny,whose order of gender in lives is contrary to the above one(female first and male later).this type of change  is the most common form of hermaphroditism in fish in nature.About 75% of all sequentially hermaphroditic fish species are protogynous,and the typical examples are Wrasses(隆頭魚)

parrotfishes(鸚哥魚)

 and groupers(石斑魚)

For there are too much knowledge behind this phenomena,I can not introduce all of them in one time.Consequently,I will continue this topic in the next few weeks.Hope all of you can enjoy it.

the brief introductin of hermaphroditism vedio：https://www.youtube.com/watch?v=LHwQSrn3F24

hello everyone.Today I'd like to start the topic from a extreme special plant─ titan arum.As it's name's meaning,the plant looks extremely “titanic”when it blooms. It is a flowering plant with the largest unbranched inflorescence in the world.An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches.Easily to say,it is a part of flower.However,it is useless to tell how big it is without showing picture.So the picture is here.

It is an amazing plant,isn't it?Or some of you may think that it is disgusting due to its looking.If you think so,your instinct is right because it will really make you disgusted on account of its flower's ordor.It is said that it smells like decomposing mammal.Due to the fact,titan arum has other names such as corpse flower,carrion flower,or corpse plant.Even people in Indonesia give this plant an Indonisian name called  bunga bangkai – bunga means flower, while bangkai can be translated as corpse, cadaver, or carrion.Despite it's uncute looking and smelling ordor,it is still an interesting and cool plant.I hope everyone enjoy learning this specific creature in front of the computer instead of approaching it and experiencing it's “bangkai” smell.

this is the introducting video of titan arum.Hope everyone can enjoy it.

reference：Wiki