Thoughts on T. pustulatus/T. lineatus hybridization

[Hilly]

We know juvenile Lineatus exhibit the red spots i'm staring at one right now as I type this, but most juvenile lineatus have only 1 or 2 red spots in what then turns into the banded lines. If you look at the first pic in the juvenile pustulatus link on my last post you will notice several spots and a very subtle difference in base colour to Lineatus (plenty of juvenile lineatus pics on here) . At a very small size it is extremely subtle differences in them which has always caused the confusion. I agree you are going to have a hard time finding one, as most of us do. But I wish you luck in your search and the more info you are armed with the better. Plus a Lineatus is hardly a 2nd prize.

[maryhm]

That was some good information! I did not realize that most of the juvenile Lineatus were exhibiting spots. Did you know I've never even seen a Lineatus?? The only Giant FW puffer I've seen so far is the Mbu. So I have been basing everything off of what I'm reading. What you just stated backs up a lot of my original thought- that exporters in Africa (one would hope not importers in the US/Europe, but it's possible) are seeing the juvenile Lineatus with extra red spots and maybe a little lighter base color and passing them off as Pustulatus, even though they know they aren't. It's about the money.

My question now is this- do the juveniles that are exhibiting an "aberrant" color pattern which is causing them to be mistaken for Pustulatus keep some form of aberrant coloration into adulthood? Or do they turn it to what every other typical Lineatus looks like?

[Hilly]

Generally as a Lineatus grows the spot disappears some develop more defined banded lines than others so you get some specimens with truly striking lines and others that havent but all to the trained eye are the Fahaka (when you've looked at loads of pictures ). When they are young you just dont know what you are going to get.

What brings up the most debate with the Pustulatus is that there doesnt seem to be a specific patterning so you get the generalisation of is it a cross between the two, which comes back to the hybridization term showing what could be characteristics of the two, but it could be that is just how the cross rivers patterning develops you get some with lots of spots and others with just a few as you get Fhakas with defined lines and those without.

I'm not the most scientific when it comes to this stuff though, some of the other guys are way more knowledgable on that side than I am, I just go on visual markers and my gut.

Some videos of Cross Rivers to compare against each other:

[J-P]

aww the video doesn't play

[Hilly]

Weird i've just played all 3 simultaneously in the post.

[J-P]

J-P is having technical difficulties

it works in firefox but not in chrome

[maryhm]

Generally as a Lineatus grows the spot disappears some develop more defined banded lines than others so you get some specimens with truly striking lines and others that havent but all to the trained eye are the Fahaka (when you've looked at loads of pictures ). When they are young you just dont know what you are going to get.

Do we have any idea at what size this change normally occurs?

[Corvus]

I'd say the ones in the video are "T. pustulatus", but they will develop lines at some point (differs from specimen to specimen). What is still unclear is, what are the characters to tell them apart and are they a valid species. The spots hardly can be such a character if adult "T. pustulatus" get the lines.

[Hilly]

As usual Corvus you are right, i've been trawling through a lot of Pustulatus pictures, always thinking that the lighter green base colour was a factor and then I see ones with general body colour of a Fahaka that you could class as Pustulatus. Then the more slightly squashed face but then I see others with a slightly longer face that have what we would expect Pustulatus markings to be.

Difficult with only pictures to go on that dont focus on it but are there any difference in the narines. The only thing I can see that seems to remain fairly constant is the tail never looks as big as on a Fahaka.

[Corvus]

So far I've failed to find a definite character for differentiation, that's where my doubts come from on the taxonomic status. The nostrils are very similiar on all African Tetraodon spp.

I've tried to evaluate some measurements of tail/total length, but found not a clear difference as I would have wished to.

[xrayjeeper83]

I dont have any relative input but the cross rivers in those videos are stunning

[Hilly]

There is 1 pic that intrigues me Corvus and I wondered what your thoughts are on it. Im sure you will have read the post it is in, the 1 with 2 Pustulatus in, one which grew much larger than the other and devloped the stripes and the other stayed smaller with the spots. Both came in the same batch of fish at the same size. What is your thought on it.

I can post a link if required.

[Corvus]

Yes, I know which picture you are talking about. I've linked to it somewhere, too. I believe they were from a batch where all came with spots first. I think they are all the same species, the "T. pustulatus". I would not expect them to develop the stripes at the same time or even size, but I think they all did eventually. Would have to look up the original. The time of color changes of fish can vary by a lot of factors mostly space, environmental design, light and if other fishes of the same species (males or females?) are available.

[Hilly]

If I can vaguely recall the 2 specimens were kept by different keepers and then re-united so as you say there are a lot of variables. Feeding regime and water maintenance for optimum conditions being at the top of that list for me.