Firemouth cichlid

Water parameters

Tolerated range for this species. Aim for the middle of each band rather than the extremes.

Tank and habitat

Substrate: sand.

Behavior

Plant interaction: digs around roots.

Feeding

Omnivore that eats anything. Pellets (cichlid-specific sinking or floating), flake, frozen bloodworm, frozen brine shrimp, frozen mysis, live food, and blanched vegetables. They sift through substrate and pick food particles from sand, so sand substrate allows natural feeding behavior. Feed twice daily. A varied diet improves the red coloration on the throat and ventral area. High-quality cichlid pellets with color-enhancing ingredients (astaxanthin, spirulina) make a noticeable difference in display intensity.

Compatibility

• Less aggressive than its Central American cichlid reputation suggests. The firemouth's threat display (flaring gill covers to show the bright red throat) is largely bluff. Against truly aggressive cichlids like convicts or Jack Dempseys, firemouths usually back down.
• Breeding pairs do become territorial and will defend a zone around their spawning site. The tank needs to be large enough (200 L) that other fish can stay out of the defended area.
• Good tankmates: other medium-sized Central American cichlids of similar temperament (convicts if the tank is big enough, blue acara), larger barbs, rainbowfish, catfish, and larger loaches. Avoid small community fish that would be bullied or eaten.
• The display behavior is the main attraction. Males (and females to a lesser extent) extend their branchiostegal membranes when threatened, revealing the vivid red coloration under the jaw. It's one of the more interesting visual behaviors in the cichlid world.

Origin and habitat

Thorichthys meeki is a Central American cichlid from the Atlantic slope of southern Mexico, ranging across the Yucatan Peninsula and south through Belize into northern Guatemala. It lives in shallow, slow or still water that is often turbid, including rivers, ponds, canals, and cenote and cave systems, over sandy and muddy bottoms. Walter Brind described it in 1918, originally as a subspecies of T. helleri, and the name honours the American ichthyologist Seth Eugene Meek, who produced the first book on Mexico's freshwater fishes and who erected the genus Thorichthys in 1904. The body is grey to olive-yellow with a row of dark vertical bars and fins edged in red and flecked with blue, but the standout feature is the brilliant orange-red on the throat and lower gill covers. That colour drives the species' signature threat display: a male spreads the membranes under his gill covers wide, flashing the red throat and making himself look far bigger to rivals and intruders. The display is mostly intimidation rather than a prelude to real fighting. Maximum length is around 17 cm, with females smaller. Naturalised populations have been recorded outside the native range, including in Hawaii and Puerto Rico. It feeds mainly on the bottom, sifting sand for invertebrates, small molluscs, and detritus.

Breeding

A substrate-spawning cichlid that forms monogamous pairs. The pair picks and cleans a flat surface, a rock, a slate, a piece of bogwood, or even the tank bottom, and the female lays a clutch that can run to a few hundred adhesive eggs while the male follows to fertilise them. Both parents guard the eggs and turn markedly more aggressive toward tankmates once a clutch is present. The eggs hatch within a few days, and once the fry are free-swimming the pair herds them as a tight cloud, the female staying close while the male works the perimeter. Parental care runs for several weeks, and well-conditioned pairs spawn again on a regular cycle. Free-swimming fry take baby brine shrimp and finely crushed food.

Common problems

The firemouth's aggression is mostly show, so its main trouble in a community comes from tankmates that call the bluff. Housed with seriously combative cichlids such as large convicts, Jack Dempseys, or red devils, a firemouth ends up stressed and hiding, so it should be matched to fish of similar temperament rather than similar size. Two males in a tank that is too small will lock jaws and can injure each other's mouths, which then risk infection. Newly bought fish sometimes arrive carrying ich, which responds to standard treatment. Given clean water, a varied diet, and enough space, the species is hardy and long-lived.

Bioload

Further reading

• How to cycle a fish tank
• Stocking ideas by tank size