sexual dimorphism in shark catfish

Wings · Post by **Wings** » 07 Jun 2006, 19:44

im about to buy some baby shark catfish (about 5cm) and does anyone know a way of sexing them at this age?

MatsP · Post by **MatsP** » 07 Jun 2006, 20:07

Is this something like this:

? [Often called P. sutchi in the shops, as they don't keep up with the scientific side quite as well as this web-site does...]

In that case, can I advice that you don't buy them.

And to answer your actual question: they would have to be significantly larger to be sexually distinguishable... I don't know how big they need to be, neither does the Cat-eLog say so, but I would guess it becomes apparent no sooner than at a foot in length, or more...

They do grow a bit big for home aquaria...

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Mats

Wings · Post by **Wings** » 07 Jun 2006, 20:13

thanks for the reply. i was talking about Hexanematichthys seemanni which only grow to about 35cm. Pangasius hypophthalmus would be a bit large lol

MatsP · Post by **MatsP** » 07 Jun 2006, 20:20

If you look at , it actually says how large they need to be to be sexed - and it's surprisingly large for a fish that grows to 350mm... Which makes me think that they may grow a bit larger...

You do realize that these fish require transition from fresh to saltwater as they mature, right?

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Mats

Wings · Post by **Wings** » 07 Jun 2006, 20:26

thanks i dont know why i didnt spot that lol. yeah i have been wondering about the size - most websites have said it grows to about 35cm but a couple have said 60cm! the owner of the pet store said they would only grow to about 20cm. i do have a 500l tank for when they grow larger though, and i could get a larger one if necessary. thanks for the info