ID Please - Green leafy thingie eating my plants!

[poohbear]

Help! I'm new to fishkeeping and have been at it for about a month. Have two clowns and a few anemones in my 26 gallon marine tank.
Now, I have noticed this leaf like insect which is sucking the green out of my plants! shall I get rid of it or is it ok to have in there? I have already lost one red plant due to low light (it disintegrated) but I have now fixed the lighting issue...
Any help is greatly appreciated!

 

[spanko]

You ahve what a lot of hobbyists would die for. A Caulerpa sp. sap-sucking sea slug.
Be very happy here and enjoy it. As it looks like you may have already noticed the plant is growing rapidly and may in fact take over the tank.

 

[poohbear]

Wow Spanko! Thats was a fast reply! Many thanks
While it may be something hobbyists would die for, the fact remains that it is killing my plants! Should I be worried? Though you are correct is saying that my plant which the sea slug is feeding on is indeed growing very, very rapdily! A pic is attached which shows how fast it's stems are growing. In fact, I have had to place it at the back of the tank so that the stems do not cover the entire front! You can also see the sea slug feeding on the stem towards the left of the image...
While we are at it, I would appreciate another ID for something which I thought was a Spagetti worm but am not sure. It is coming out of the sand and has stuck itself on my tank wall. Has many many thin hair like antaenna which are growing....
If possible, could you also identify the 3 varieties of plants in my tank? I know I am asking for a lot of ID's but I am new (and excited) about this hobby. I'm already planning my second tank I can post more pics if you cannot make them out.
Thanks in advance!

 

[spanko]

This picture looks like Caulerpa racemosa.

Hard to tell about the rest without a closer picture.
And yuppers that looks like a spaghetti worm to me.

 

[poohbear]

Here you go Spanko!
If you are familiar with the species, I would appreciate an ID for the 3 varieties of plants I have in my tank so I can look after them better. A pic of the first is given in the pic in my earlier post above where you have identified the spaghetti worm and the other two can be seen in the folowing pics.
Once again, thanks for your help and this is indeed a fantastic forum I have discovered. Once which I hope to stick around with in the years to come and be a contributing member!

 

[spanko]

Codium sp.

Caulerpa taxifolia