Clown Goby Cichlid Care Guide - Aquarium Setup, Diet & Breeding

The Clown Goby Cichlid, Eretmodus cyanostictus, is a compact, laterally compressed Tanganyikan cichlid with a blunt, goby-like profile. Its body is usually brownish, grey or olive, marked with blue or turquoise spots and lines that become especially striking on the face, cheeks and fins. Colour varies between local populations and can intensify when the fish is displaying or breeding.

Despite its small size, this species has a lively and assertive personality. It spends much of its time close to rocks, using its specialised lower mouth and scraping teeth to graze algae from hard surfaces. It is a strong swimmer in short bursts and often moves in a characteristic hopping or darting manner between rocky resting places.

In the wild, Clown Goby Cichlids inhabit the wave-washed, shallow margins of Lake Tanganyika. Their specialised body shape and close-set fins help them negotiate crevices and cling to exposed rock while feeding, and their diet is largely based on the algae and microorganisms growing over the lake's stony surfaces.

This species is one of the lake's distinctive goby cichlids and is adapted to the unusually stable chemistry of Tanganyika. It is generally kept as a pair or in a carefully planned community rather than as a conventional shoaling fish, since adults can be territorial around preferred rocks and spawning sites.

Clown Goby Cichlids are endemic to Lake Tanganyika in East Africa. They occur along rocky shorelines, particularly in the southern and central parts of the lake, where the water is warm, alkaline and highly mineralised.

A pair should have at least 100 litres, with a footprint of roughly 90 cm by 30 cm or larger; a longer aquarium is preferable because this territorial fish needs bottom space. Use a sandy or very fine-grained substrate and build sturdy piles of rounded rocks with caves, crevices and broken lines of sight. Leave some open grazing surfaces, maintain strong filtration and circulation, and secure all rockwork directly on the tank base so it cannot be undermined. Bright lighting can encourage natural algae growth, provided water quality remains stable. The water should be hard and alkaline, with a temperature of 24–27°C and a pH around 8.0–9.2.

Adults reach a maximum of about 9 cm (3.5 in) in total length. Males are often slightly larger and more robust than females, although the difference is modest.

This species is primarily an aufwuchs grazer and should receive a varied herbivorous diet. Offer high-quality spirulina or algae-based flakes and pellets, along with blanched vegetables such as spinach, courgette or cucumber. Small amounts of protein-rich foods, including frozen cyclops or baby brine shrimp, can be used occasionally, especially for juveniles and breeding fish, but rich meaty foods should not form the basis of the diet.

Clown Goby Cichlids can be kept with suitably sized, peaceful Lake Tanganyika species that occupy different areas of the aquarium, including smaller Julidochromis, rock-dwelling Neolamprologus and carefully selected shell-dwellers. Tankmates should tolerate hard, alkaline water without being excessively aggressive or competing for the same rocky territory. Avoid large predatory cichlids, boisterous Malawi cichlids and combining multiple goby cichlid species. Conspecifics may fight if too many are confined in a small footprint, so a bonded pair is often the safest arrangement.

Clown Goby Cichlids are biparental mouthbrooders that usually breed as a bonded pair. The pair lays eggs on a rock or other firm surface, after which the female initially carries the clutch in her mouth. The eggs or larvae are commonly transferred to the male, who continues to brood them before the free-swimming young are released. Provide sheltered rockwork, excellent water quality and small foods such as newly hatched brine shrimp for the fry.

Sexual differences are subtle. Mature males are commonly a little larger, deeper-bodied and more intensely coloured, while females tend to be slightly smaller with a rounder abdomen when carrying eggs. Reliable sexing is difficult outside a mature pair.