Keeping and breeding goby cichlids

Keeping and breeding
goby cichlids
by J. McCann & T Hammond

Distribution

E. cyanostictus inhabit the shoreline areas of the lake. This, is called the "surge zone" as it is continually washed by wind-driven waves. They are often found in water less than 1 metre deep, and rarely below 3 metres. The pH levels in the surge zone are normally higher (9+) than the main body of the lake due to the wave action on the shore line releasing oxygen from the water (faunal exhaust).

Eretmodus cyanostictus

Maintenance

These are the tank details and conditions that can be used to keep and breed E. cyanostictus.
A pair of Eretmodus can be kept in a 24" aquarium, but a larger tank is preferable. The aquarium should contain plenty of rocks or flowerpots, forming a system of caves that extends almost to the surface in places (to provide refuges for the female if the male becomes aggressive). Stones laid flat on the bottom, at the front of the tank. Will grow algae on them giving the fish some where to perch and graze.

The tank needs to be in a position to catch some natural sunlight, or be well lit with tubes, to encourage the growth of algae. Algae is very beneficial to the health of these fish (see Diet below)

Filtration is another thing that requires some thought. I have found that these fish thrive over a sand bottom (sand is used by the fish as a digestive aid, see Diet below). The sand I use is called "Play Pit sand". Using sand means you can not use under gravel filters, so you will have to rely on power filters. My choice is the external canister type, with the intake set well above the sand base, and protected to stop sand being drawn into the filter (something I realised after quickly wearing out the impeller housing on a Fluval filter!!). The flow rate should be higher than required for the tank size as water movement/oxygenation is a requirement for these fish. With that in mind the output should re-enter the tank from a from a height, or through a venturi.
Extra aeration may be required and can be supplied by airstone and pump.
pH 8+, normally coral sand/gravel or crushed shell in the filter will help keep pH up around this mark.
Temp 79-81o.
Nitrate less than 15ppm the lower the better.
Water changes of 15%+ per week if stock is small if stock increases monitor water conditions and change as necessary

Diet

Goby cichlds have the characteristic cichlid appetite; even wild caught specimens will happily eat most standard aquarium foods, BUT be careful. A large part of the diet should consist of vegetable matter such as blanched chopped peas, lettuce, and good quality spirulina or vegetable-based flake. An algae-covered rock from another aquarium is a real treat, and all the algae will be speedily consumed. Small crustaceans and insect larvae are eaten in the wild, and can be provided in the aquarium (frozen foods are the safest). Frozen Cyclops, mysis shrimp and frozen brine shrimp can all be used for occasional feeds. However stay away from bloodworm, and meat or fish products.

The use of sand in the aquarium is beneficial, as it is thought to aid the passage of food through the intestine.

Breeding

Sexual differences-Unfortunatly goby cichlids are sexually monomorphic (males and females look similar) and the only real way to tell is to vent these fish. Click here for details on how to do this. Slight differences in size and build,(males bigger and bulkier) may give you a clue, but it cannot be relied on.

Breeding-Eretmodus,Tanganicodus and Spathodus erythrodon are biparental mouthbrooders. (Spathodus marlieri are maternal mouthbrooders and there slightly different behaviour will be marked by *SPATHODUS). This type of reproductive behaviour requires a stable long-term pair bond. The only way you can get this is to introuduce a group of fish of similar size, buying a single male and female is usually a recipe for disaster, with one of them (usually the female) getting harrassed to death. Unpaired specimens are aggressive towards each other, and when a pair has formed they are very obvious. They will guard a territory against others of the same species. At this point unpaired fish should be removed immediately for their own safety.

When the female is ready to spawn her short conical ovipositor appears and she cleans a flat surface. The pair circle the stone, and then the female swims slowly over it (see all this on the video), lays one or two eggs, and immediately turns to pick them up in her mouth. The eggs are bright orange-yellow, app 4 mm in diameter. The male then swims over the surface and the female nuzzles his vent, taking up sperm to fertilise the eggs. This is repeated until the female has produced between 12 and 30 eggs, depending on her age, size, and condition.

The female incubates for approx 15 days, during which time the eggs hatch. Then she transfers the larvae to the male who completes the incubation. The transfer normally happens at the spawning site. The female spits out one or two fry at a time, which the male immediately catches. At this stage the larva is basically a yolk sac with a small head and tail.

The male incubates for a further 9-16 days. If the spawning has taken place in a community tank he should be removed to a separate aquarium; but this is not necessary if the pair are kept on their own as they completely ignore their fry. The fry need small crevices in which to hide, so piles of small stones or shells should be provided, the intakes of power filters must be screened now if not done when setting up the tank, (I find the course foam from an internal filter is ideal). The fry are often released over a period of time, usually at night. The male swims around the tank and pauses to release a few fry; if they find suitable hiding-places the male swims off, but any which remain "hovering" in the open will be taken up again. This behaviour would seem to ensure that the fry are safely dispersed around the pair's territory. The fry can be carefully removed as soon as the male has released the whole brood and started to feed again; this minimises disturbance to the adults, who may soon be ready to spawn again.

*SPATHODUS The female Spathodus does the role of both the male and female.

Newly released fry are about 10 mm long and have relatively small mouths. The best first food for the fry is Artemia nauplii, but they will soon accept a wide range of foods. After a few weeks they start to graze on algae. This can be supplemented if a magnetic algae scraper is used to clean the glasses of other aquaria and then rinsed in their tank. They grow quite rapidly and can double their body length in 6 weeks.

As the male incubates the fry, the female is able to feed again, so she may be ready to spawn again only two days after the male has released the previous brood.

*SPATHODUS As the female holds for double the length of time, compared to other goby females she is not ready to spawn again as quickly.

Problems may arise if the pair do not synchronise their reproductive states. The male may attack the female if she is unwilling to spawn or to transfer the fry. So pairs must be watched closely and the tank should contain refuges just large enough to accommodate the female, but too small to admit the male. You must be ready to intervene and separate the pair before the female is seriously injured.

If the pair are separated after spawning, or if the male does not take over the full brood of fry, then the female is capable of completing incubation on her own, but this taxes her strength and she will take much longer than usual to return to spawning condition.