Ectodus descampsii has been officially described by Boulenger in 1898. Its species name descampii is in honour of Captain Descamps who catched this species and send them back to Boulenger. The genus name Ectodus has been comes from two Greek words: “Ek” meaning from or out and “Odeus” meaning teeth.
In the past there has been some confusion about the origin of the specimens Boulenger described. He stated they originated from the northern part of Lake Tanganyika but he described the characteristics of the southern population. The northern population is being called Ectodus sp. “North” and has not been officially described yet. They differ from descampsii in length and the location of the black dot on their dorsal fin. Descampsii can reach a maximum total length of around 10,5 centimetres and the black dot is located on the centre of their dorsal fin. Ectodus sp. North grows a bit bigger, reaching a maximum total length of around 14 centimetres and having a black dot more to the front of the dorsal fin.
Sub-adult Ectodus descampsii are silver coloured but will soon get the characterising black dot on the center of their dorsal fin. Only when they reach 5 centimetres in length the difference between males and females starts to show a little bit as males get a little more colour on their fins. Their bodies are torpedo shaped and very elongated. Their caudal fin is forked but what springs to your attention first is their relatively large dorsal fin with the black dot in the center. As males mature this black dot gets deeper black and their pectoral fins grow black accents.
Their silvery colour is a perfect camouflage in their natural habitat. In the shallow waters above the sand the silvery colour reflects the colours of the sand, making them very hard to see in the water.
Ectodus descampsii is a social fish that likes to be surrounded by conspecifics. They can become very shy when kept in too small a group or with larger aggressive fish. It is best to keep them in a group of 6 specimens or more. Groups should have twice as many females than males to spread the males attention to the females and to avoid to much conflicts between the males. Males show some fight over the females and territory but usually they leave the battle unscathed.
If the fish are scared they can hide quickly. For example, when you suddenly put your hands in the aquarium to move some rocks, it could look like your Ectodus descampsii have vanished. They probably dug themselves into the sand to hide. So be careful when moving rocks around not to place them on top of one of your fish.
In terms of behavior and appearance the ectodus descampsii is very similar to other sand dwelling cichlid fish such as the Lestradea perspicax, Lestradea stappersii, cardiopharynx schoutedeni etc. Recent DNA research however revealed them to be more closely related to featherfins from the Aulonocranus, Cyathopharynx, Cunnungtonia and Ophthalmotilapia genera.
The Ectodus descampsii habitat runs from Moliro at the border of the Democratic Republic of Congo in the south of Lake Tanganyika to Utinta Bay in Tanzania. They inhabit the shallow waters over sandy bottoms.
Ectodus descampsii finds his food in the sand. They constantly take bites of sand, sometimes even diving with their entire head into it looking for food. You can spot small pits all over the sand where they dug in, just like the sand you see around Callochromis species. They filter the sand through their gills, sifting out everything edible like insect larvae, invertebrates, algae and diatoms.
Because they are primarily carnivore you can feed Ecotus descampsii best with meaty foods such as bloodworms, daphnia, mysis, brine shrimp etc. They are not very picky in terms of food. Usually, they wil take any fresh or frozen foods. You can also give them flakes and granule.
Because Ectodus descampsii is a fish that lives in groups and males need some room to make a territory, you will need an aquarium of at least 150 centimeters to house a group of two males and four females. This seems pretty generous for a fish of just 11 centimeters long but is really needed to provide enough room for the males territory’s.
Sand should be used as substrate, make sure it is rounded and has no sharp component, filter sand is ideal for aquarium use. Put some rocks in the center of your aquarium and along the edges but leave a large area of sand about. The rocks in the middle are meant to break the lines of sight so that on both sides a male can create a territory.
The water temperature should be between 24 and 27 degrees celsius at a pH of 7.5 to 9.0. Ectodus descampsii won’t need any plants but they will leave them alone if you want them. If you want to use plants make sure to use strong plants like Vallisneria and Anubias.
SPAWNING TANK AND CONDITIONING
The male creates a nest by digging a sand crater. The crater may get as large as 40 centimeters in diameter and 10 centimeters diep.
Make sure that the fish are fed with high-quality live and / or frozen food so that they are in optimum condition to mate. Apparently, sunlight that falls into the aquarium in the morning increases mating activity. If the Ectodus descampsii will not breed, you might consider moving them to a breeding tank that catches some morning sunlight.
In the shallow sandy waters the silver colored Ectodus descampsii are hard to see for predators. This also makes it difficult for the males to attract females. If the male wants to attract a female he will intensify his colors. The black dot on his dorsal fin becomes deep black, his ventral fins and throat turn black as well. Their nervous system can control their skin cells that contain pigment (melanocytes). Within seconds they can switch between the mating black coloration and their silvery inconspicuous normal color.
The male will now try to lure females into his nest crater and aggressively keeps other fish away. He swims around his crater and showing females his flank and beautiful colors. If a females is interested she joins him at the center of the crater. They circle each other as the females lays the eggs and the male fertilizes them. The female turns around and picks up the eggs and holds them in her mouth to incubate them.
It may happen that a sub-dominant man posing as a female disturbs the couple during spawn, he quickly fertilizes eggs from the female before the dominant male gets the chance to remove him forcibly.
A spawn may consist of 15 to 40 eggs. After spawning the male has done his job and has no further part in raising the fry.
Rearing the Ectodus descampsi fry
The eggs hatch inside the females mouth after 3 to 4 days. The newly hatched Ectodus descampsii remain in their mother’s mouth for a total of 3 weeks after spawning feeding on their yolk sac. The female doesn’t eat during this period.
After three weeks of the spawn the fry are big enough to be released. The female will look for a quiet place and spits them out. The fry will form a school and will have to take care of themselves from now on.