How can we make our Red Devils (Lab's) get thicker lips?

[duanes]

It has been suggested that (beyond the genetic component) the large lips are a product of the abrasion of grazing off hard rock substrate. There are also those African rift lake cichlids that graze algae off rock substrate, and have similar pronounced lips as their Nicaraguan cousins.
I started using Repashy foods and would pour them on lava rock after heating as an experiment, and drop the food covered rock into tanks to see if I could mimic the same behavior, and get the same results, but moved before I had enough time to get results.
For those who don't know, Repashy foods come as a powder which you sort of cook, and let set. I would cook it up, while still viscous pour over lava rock, and put in the fridge to set. After being set, drop a few food infused rocks in the tank so the fish were forced into rasping it off those rough rocks to get their nutrition.
Might be worth trying, and reporting results as time went along, and might be even more dramatic if it the regime began with juvies, and checked and photographed throughout a lifespan.

 

[convict360]

fillers

 

[RD.]

You typically won't see those large rubbery lips in captive bred fish. In the wild, those thick lips serve as gaskets, and are used to extract prey from the cracks and crevices in the rock piles where they feed. You'll see the same thing with some of the fish found in the Rift Lakes, such as Placidochromis milomo. IMO using gel food will not net the same results. It has also been speculated (by Konings and another author that slips my mind at the moment) that in the wild those large lips carry numerous scent sensory pores, which are utilized to seek out prey in the cracks and crevices of the rocks. I believe that I have posted regarding that in the past. Again, a characteristic that is most likely lost on domestic fish.