Theraps coeruleus Breeding Guide

Breeding notes for Theraps coeruleus (Rheoheros coeruleus), a small current-loving cichlid from the upper Tulija River in Mexico.

Overview

Theraps coeruleus was described by Stawikowski & Werner in 1987 and is now usually placed in the genus Rheoheros as Rheoheros coeruleus. According to FishBase it occurs on the Atlantic slope of Central America in the upper Tulija River within the Usumacinta drainage of Mexico, reaching about 12.0 cm SL. It is a current-loving fish of montane habitat that feeds on aufwuchs and encrusted invertebrates such as small crustaceans.

Breeding Setup

FishBase records water parameters of pH 7.0-8.0, hardness 9-20 dH and temperature 23-25 degrees C for this species, with a benthopelagic, flowing-water lifestyle. A breeding tank should therefore offer neutral to slightly alkaline, moderately hard water with strong, well-oxygenated flow and a sand substrate dotted with rocks. The Aquairi record classifies the species as a substrate spawner of intermediate breeding difficulty, so flat stones and sheltered surfaces should be provided as potential spawning sites.

Common Challenges

Specific captive spawning accounts for this species are limited in peer-reviewed and specialist editorial literature. The principal challenge is maintaining the clean, cool, flowing conditions of its montane stream habitat while keeping a settled pair. Exact spawn sizes, incubation times and fry-rearing protocols are not documented in the sources consulted and are omitted here rather than estimated.