Thorichthys meeki

This is a fish with a tall, slightly elongated body and a noticeably large head. In males, the dorsal and anal fins are elongated and pointed. The body is blue-grey in colour, with several dark spots along the centre and indistinct cross-bars. A striking feature is the bright red colouration of the lower body.

This species naturally occurs on the Yucatan Peninsula, in what is now Mexico and Guatemala. Thorichthys meeki inhabits lowland rivers with moderate flow, preferring shallow water no deeper than 1.5 metres. The fish is well adapted to changing water conditions and tolerates turbid water and brackish conditions. Because of this hardiness, it can be found in river deltas and small lagoons where fresh and salt Atlantic waters meet.

These fish prefer to live in groups, though they can also be kept in pairs. Thorichthys meeki is a monogamous and territorial species that actively defends its space and offspring. During breeding, the fish becomes more aggressive and may attack other tank mates. In a small tank, it is not recommended to keep other fish of similar size with it. Overall, the species is compatible with many fishes, provided they are large enough not to be accidentally eaten.

A pair of adults needs an aquarium of at least 200 litres. Strong plants with robust root systems are preferred for décor. A variety of shelters are essential. Besides traditional decorations such as castles or sunken ships, you can use ceramic flower pots or plastic pipe sections, which can look quite natural in an aquarium composition. Driftwood, branches and tangled roots not only enrich the décor but also serve as excellent substrate for algae growth, which is a valuable natural food source. Use coarse sand as substrate, supplemented with a few smooth boulders. Although the fish adapts to a wide pH range, soft neutral water is preferred. Replace 15–20% of the water weekly. For details on water parameters and how to adjust them, see the section on water chemistry. Standard equipment includes a filter, lighting, a heater and an air pump.

In nature, Thorichthys meeki feeds on small crustaceans and plant debris, often sifting through the substrate for food. In the aquarium, they readily accept any high-quality commercial foods such as pellets and flakes. The diet can be varied with live foods: daphnia, mosquito larvae, small earthworms and bloodworm. It is very important to supplement the diet with plant-based food or ensure it is already present in the dry food.

Successful breeding requires a proper diet that includes both dry food and meat products, as well as high water quality. The male and female form a stable pair and lay eggs on a flat surface, such as a stone or even the aquarium glass. The male then fertilizes the eggs by moving along the clutch. The total number of eggs laid can reach several hundred. During incubation, the female stays near the clutch, protecting it from threats, while the male patrols the territory. The fry usually hatch in 4–5 days and begin to swim freely. The parents continue to protect the brood for several weeks, after which it is advisable to move the fry to a separate tank. Interestingly, young fish of this species sometimes eat their first brood.

This species is quite hardy, and health problems usually occur only when conditions deteriorate significantly, feeding is inadequate or poor quality, or if the fish are exposed to infected individuals.

When selecting specimens, pay attention to their activity and the cleanliness of their skin. Healthy fish are curious, have bright colour without spots, deposits or fin damage, and react actively to food. Avoid specimens showing signs of emaciation, a sunken belly or an unnaturally distended abdomen, which may indicate internal disease. Check the eyes: they should be clear, without cloudiness or turbidity. Watch the behaviour: the fish should not constantly hide in a corner or make erratic movements. Look for the absence of visible parasites on the body and gill covers, which should fit snugly against the body when the fish is calm.