3 replies to this topic

[DaveW]

Hi,

I'm just beginning trying to key out fishes using anatomical traits, etc. Working on a supposedly Rosy-red Minnow (feeder fish) from a local pet shop. Mainly using Pflieger's "Fishes of Missouri". It keys out okay as a Fathead, except that both this book and Page & Burr (Peterson guide) state that Fatheads have a black peritoneum.

 

Does having a silvery peritoneum disqualify this as a "rosy-red"?

 

Thanks!

Dave in Boise

 

 

[Matt DeLaVega]

A rosey red is a fathead. So no disqualification. Are you saying rosey red doesn't have a black peritoneum? I would assume that is just lacking due to the rosey red morph, whatever ism that is. No production of melanin?

[DaveW]

Matt, Thanks for your response. I haven't seen anything stating whether a "rosy-red" (being a subset of Fathead) has the same, black peritoneum  stated in keys for the Fathead--I assumed they would, but maybe not. Are rosy-reds generally paler than Fatheads? If so, what you suggest, low melanin production, might indeed produce a silvery peritoneum?

[Matt DeLaVega]

Yeah, best I got. Rosey reds are melanistic or amelanistic or one of those other istics that the herp hobby loves so much. I would assume that it is very possible that this genetic condition could change the color of the peritoneum. Good luck with it, sounds like professor? tried to throw you a curve.