Sex of Diodon holocanthus
I just purchased a puffer fish (Diodon holocanthus) and he/she is about 4 inches. How can I tell what her/his gender is?
<Hi Heather,  It's a question that is asked all the time, but sadly we don't have an answer for.  None of the experts in the Puffer Community have figured out a way to tell the sex of a holocanthus (Common Porcupine Puffer).  There are many rumors around it...  the spots on the body, the length of the spines on the forehead, the ratio of the size of the eyes to the body...  All of these ideas sound like it could be something... but sadly there really isn't any way to know for sure, outside of having it checked with blood sample at a lab.  Which I'm quite sure could be done, but the cost would be rather high.  out of the 150+ species of puffer around the world (from freshwater to Marine) there are only a handful of them that actually show Sexual Dimorphism (males females look different).  Almost all are found in the freshwater species.  Wish there was a way to tell exactly, but as it stands now it's just a guess.  Thanks -Magnus>

Porcupine Puffer Male/Female?
Hey! I got good news, and bad. My puffers are getting along perfectly, they love each other.. But my female black boxfish has recently pecked some skin off of my puffer, what should I do so it doesn't get infected, etc?
<Is this fish in a tank by itself? I would place it so... Boxfishes can be quite toxic, and shedding is a bad sign of potential release... Please read: http://www.wetwebmedia.com/boxfshfaqs.htm
Bob Fenner>
Thanks a lot for any help! Colin Davis

Re: Porcupine Puffer Male/Female?
Thanks for your help, it answered a lot of my questions.
Even though I have a relatively small tank (30-33gallons tall), I have two puffers in there. They are both the same size (3-4" inches). I know I have done everything wrong by putting in another one after the original one has already claimed his territory. But is there anyway to gradually and peacefully let them get used to each other?
<Sometimes these (Diodontids) Puffers can be kept more than one to a system, but yours is way too small for any long term habitat... Two won't go in a 33 gallon volume. Bob Fenner>
Or do you have any suggestions? I would appreciate it if you could help me out. Thanks again, Colin Davis

Porcupine Puffer Male/Female?
Hi, I checked out your site about the porcupine puffer. But it did not answer any of my questions..
<Hmm>
I recently purchased my second porcupine puffer, they are both adjusting, gradually getting used to each other (they were in the same tank at the store before).
But my question is, the new one I just received, is much lighter in colour, almost white, where as the original one is much darker, almost a dark brown color.
<There are differences here... and they can/do change with mood, foods, water quality as well>
How can you tell which one is the male, and which one is the female?
<No external differences... you'd have to "take them apart" (not able to put back together)>
And how is it possible to breed porcupine puffers??
<Has been observed (I've even see this "in the bag" during oxygenating...). Not been spawned, young reared in captivity that I know>
Any information would be appreciated, thanks a lot.
Colin Davis
<There are a few "puffer" websites. You can use your search engines to locate them, or look on our WWM sites Links Pages. Do read through them for input as well. Bob Fenner>