Glow-In-The-Dark Pets

Okay. I feel like it's taboo to start a new thread on Tony's awesome Image of the Day, but I liked this one because a) I thought it would spark some good discussion and b) I found it too interesting. I kept coming back to the image and looking at it.



The caption to the image is as follows:

A few genetically modified Medaka fish glow in the dark as they swim in a tank in Taipei on Sept. 6. Taiwan aquatics firm Taikong Group, which developed the fish, plans to start marketing them in six months as the world's first glow-in-the-dark pets.

My question to you is:

Is it acceptable to genetically modify animals for entertainment (i.e., serving no real purpose)?

What do you think about glow-in-the-dark pets?