Sunday, October 30, 2011

Stage II of the jellyfish life: Planula/embryo

The first stage in the jellyfish life cycle is the planula. A planula is a ovular shaped, microscopic organism. they move them selves around using many cilia, or tiny hairs.

Planula are the byproduct of sexual reproduction in jellyfish. At least two adult jellyfish of opposite sexes must be near each other for sexual reproduction to occur. The jellyfish will release gametes (eggs and sperm) into the water and they will meet, thus fertilizing the eggs. The eggs will begin to multiply in cells up to 64 cells. Then they become a full blastocyst and eventually form a planula. Millions of planula are formed at one time.

These planula will move around with their cilia for around 7-10 days. Then they will find a clean place and settle down on it. once they have a hard surface to attach to they will begin to metamorphose into what is known as a polyp. That is the next major stage in the jellyfish life cycle.

I have a video of cannonball jellyfish sperm cells as well.


Image credits~
http://www1.fccj.cc.fl.us/dbyres/images/planula.jpg

Wednesday, October 26, 2011

What are jellyfish?

Jellyfish live very complicated lives and have a strange life cycle. I want to take the time to really explain what jellyfish are and how their life pans out. So I will start with the simplest stage of their life.

What is a jellyfish? 
Jellyfish are known as medusas. medusa refers specifically to the stage of a jellyfish's life that we all know and recognize; the jellyfish.

A jellyfish is a simple marine organism from the phylum Cnidaria. Cnidaria encompasses many corals, anemones, hydrozoans, cubozoans etc. True jellyfish are a class known as scyphozoans. Moon jellies, sea nettles, cannonball jellies (plus many many more) are scyphozoans.

There are other types of medusa, however scientifically, they aren't actual jellyfish. These medusa are all still cnidarians, they just aren't scyphozoans. I still generally refer to these medusa as jellyfish because they are very close and there is no use in getting caught in the little specialized names and classes. Examples of these include hydrozoans and cubozoans. Hydrozoans include jellies such as the crystal jellyfish or the cross jellyfish. cubozoans encompass jellyfish with four sides that form a cube shape as their bell. these are also known as box jellies. Some cubozoans are extremely toxic and others are not.

Jellyfish structure and makeup. 


There is an extreme diverse population of jellyfish in existence right now. Jellyfish within their class tend to be similar in body layout, however.

~Scyphozoans~

~Hydrozoans~


~Cubozoans~


So here are the three basic types of jellyfish. A lot of this information is not necessary to own a jellyfish. however I think it should shed some light on the first stage of the jellyfish. Part two will be on planula!

Credits to~

  • http://www.ucmp.berkeley.edu/cnidaria/images/CuboMorph1.jpg
  • http://www.esu.edu/~milewski/intro_biol_two/lab_9_porifera_cnidaria/images/hydrozoan_medusa_diagram.jpg
  • http://cronodon.com/files/Jellyfish_diagram_2.jpg

Thursday, October 20, 2011

Got my new clown fish. :)

So I got my clown fish. I actually got two. A male and a female. They seem to be getting along fairly well. The jellyfish hasn't caused them harm. Both are true Percula clown fish. The female is named Dorito and the male is named Cheeto. Fitting names I suppose. ;) 

My clown's do seem to need somewhere to hide or to rest in. I'm really not leaning towards an anemone. I know they are clownfish compatible but jellyfish and anemones don't seem to get along well. Anemones tend to eat jellyfish in the wild. I'm not sure how they would act in a tank. But I don't have enough lighting for the anemones anyways. So I'm thinking a live algae of some sort. Caulerpa or Chaeto would be the most famous, and the first choice for a reef keeper. I don't really like the way Caulerpa looks and it seems a bit spiny for a jellyfish aquarium. Chaeto seems very nice and fluffy. However I've heard it can overtake and outgrow aquariums. So I will have to ponder about that for a while. Of course I could always opt for a fake rubber anemone from petco. 

But as far as clown fish go : great choice. They really brighten up the jellyfish aquarium and add so other interesting aspects to the tank. Clown fish themselves are actually pretty funny. They tend to dance about the aquarium looking for food. They are also very attractive too. 

Saturday, October 8, 2011

A jellyfish aquarium with jellyfish and fish.

What comes to mind when you see jellyfish and fish crossing paths? You would expect to see the jellyfish capture the fish in its billowing tentacles and then sting and consume it. However that's not always the case.

According to research done by the popular company, Jellyfish Art, many fish can be kept with moon jellyfish in peace. And I know for a fact that clown fish will do fine with moon jellyfish. Of course that suddenly makes sense right? If you have ever seen finding Nemo you will remember the scene where Marlin rescues Dory from the swarm of jellyfish. Anemones and jellyfish are related because they are both Cnidarians. Their venoms are similar and clownfish don't mind either sting. 


So I've decided I'm going to get one clown fish for my tank. I really like the black clown fish, however Im not sure if I want one quite yet. I may buy a regular clown fish now or opt for a black one later. I'm not entirely sure.  Clown fish are easy to care for and look good too. 





~Images from~

http://images.wikia.com/villains/images/b/bd/Jellyfish.jpg
http://aquaviews.net/wp-content/uploads/2010/04/Ocellaris-Clownfish.jpg
http://animal-world.com/encyclo/marine/clowns/images/BlackPerculaWMC_U28.jpg