Remarks:  Clown goby cichlids are a rarely sold species of goby cichlid which are already uncommon in the hobby. Most are familiar with their close relative, the striped goby cichlid (Eretmodus cyanostictus) which they used to be considered as a subspecies of them. When the clown goby cichlid was first described back in 1988 by Konings who noted the difference between the southern and northern goby cichlid populations, it was called Eretmodus sp. “Cyanostictus North.” In 2012 after further examination, Burgess gave them their new name of Eretmodus marksmithi, solidifying the clown goby cichlid as a separate species.

  As their old scientific name indicates, the clown goby cichlid can be found in the northern sections of Lake Tanganyika. There are many different localities with each having their own unique look. The most typical look for a mature clown goby cichlid is a dark brown or tan body lined with yellow or light orange stripes, iridescent blue spots on the face, and red details in their fins. Young or stressed fish tend to be more gray and tan with just hints of these colors and patterns.

  Goby cichlids are found in shallow, rocky habitats in the surge zone of Lake Tanganyika. Here, the currents are strong and the dissolved oxygen levels are high. These highly adapted little fish have evolved in a way that their swim bladders have been rendered non-functional as to reduce buoyancy. This lack of buoyancy allows goby cichlids to better fight the surge currents by sticking closer to the bottom and hiding in rocky crevices. Their long but short dorsal fins and laterally compressed bodies further aid in this. The rocks that goby cichlids swim amongst tend to be covered in algae which the fish feed on as their primary source of food. Their down-turned mouths are another adaptation for their environment as it allows them to graze on this algae while remaining oriented to keep a look out for predators. Their morphology, which also includes eyes positioned at the top of the head that can move independently, is similar to fish referred to as gobies despite goby cichlids being cichlids with no close relation to gobies. Situations like this arise from a process known as convergent evolution which consists of unrelated organisms evolving similar features or behaviors independently. These similarities have given rise to their common name of goby cichlids.

  Due to their natural habitat being in a surge zone, goby cichlids are used to high oxygen levels and will not tolerate poor aeration in the aquarium. They also require a very high pH, hard water, and low nitrates. To ensure their needs are attended to, those keeping goby cichlids should perform frequent water changes, use heavy filtration, and provide heavy aeration which can be achieved with bubblers and wavemakers. Using a wavemaker to create heavy current will be appreciated by the goby cichlid as this mimics their natural habitat, encouraging more of their natural behaviors. With them not being very forgiving in these regards, goby cichlids are known to not be the easiest Tanganyikan cichlids to keep and are better suited for experienced keepers. Algae should be allowed to grow within the aquarium for the fish to graze on in-between feedings. Being herbivores, a diet high in vegetable matter and algae is recommended. Spirulina flakes, sinking tablets, and fresh vegetables are all good choices. Meatier foods such as mysis shrimp can very rarely be offered as a treat as feeding too much protein will cause digestive issues such as bloat. Many suspect sand plays a vital role in their digestion so it is recommended to use soft sand as a substrate.

  While goby cichlids are small, they are rather fierce and territorial. Other fish that do not dwell in the same areas of the tank as them and do not look like them tend to be left alone, but they can be very feisty toward conspecifics and members of their own kind. This is why goby cichlids are best kept as a single fish or in mated pairs. If kept like this, they can be kept in smaller tanks (20+gallons), but those looking to have a colony will need to house them in a much larger space (50+gallons). With these personalities and their herbivorous diet, goby cichlids can be a great tankmate for Tropheus. Shell dwellers and sardine cichlids are also great choices to house alongside goby cichlids.

  If one is not looking to keep goby cichlids in a community setting and instead is looking to breed them, it is good to know they are a challenging project. Goby cichlids don’t breed very readily in captivity with little being known about how to trigger them to spawn. This difficulty also comes from the fact that goby cichlids can be very picky about pairing up. Just because you have a male and a female does not mean they will accept each other. This is why it is best to either get a pre-established pair or get a group of juveniles and let them pair up naturally. Once a pair has formed, they will stay together for life. There are few differences between males and females except for the fact males tend to grow larger. Goby cichlids pick a clean, flat surface, usually a rock, to spawn on. They are bi-parental mouthbrooders so the female will pick up and hold the eggs in her mouth after spawning until they hatch. She then transfers them to the male’s mouth for him to hold for a few weeks until the fry are able to fend for themselves. Goby cichlids prove to be great parents by never predating upon their own fry and protecting their brood fiercely against would be predators. Their co-operative parenting style is unique among fish and very fascinating to watch in captivity.