Thorichthys pasionis

Thorichthys pasionis is found in the Usumacinta drainage of Mexico and Guatemala and is closely related to T. meeki, but is distinguished by its more intensely red ventral coloration, which extends further up the flanks than in the Firemouth. During spawning, both sexes display an almost glowing red-orange belly that rivals the coloration of the most vibrant cichlids in the hobby.

In terms of care, T. pasionis follows the standard Thorichthys requirements — warm, soft to moderately hard water with a varied omnivore diet and adequate space for a bonded pair. It is slightly less commonly available than T. meeki but appears regularly through specialist cichlid retailers and societies.

Breeders of this species note that the intensity of the red coloration in offspring can be enhanced through careful selection and a diet rich in carotenoids. The species is easy to breed and makes an excellent display fish for a Central American biotope aquarium.

Water: 24–28°C, pH 7.0–8.0, GH 5–15, KH 2–8; warm water essential for full red coloration expression. Tank: 180 L minimum; sandy substrate, flat rocks for spawning, plant cover welcomed. Feeding: Omnivore — cichlid pellets, krill, frozen bloodworm; carotenoid-rich foods enhance red coloration. Breeding: Shallow pit spawner; vigorous biparental care; 150–400 eggs; both parents herd fry actively. Compatibility: Medium CA cichlids and robust community fish; less aggressive than large CA species.