Tuesday, December 8, 2009

Cyrtocara moorii


Cyrtocara moorii is a beautiful, mild-tempered fish that is a delight to keep. It is commonly known in the hobby as the Malawi Blue Dolphin, and was once classified as Haplochromis moorii. Now it is the only species belonging to the genus Cyrtocara. The nickname Blue Dolphin originates from the shape of its head – a nuchal hump and bill-like mouth – which resembles that of a dolphin.

This fish is quite rare in Lake Malawi, although it has a very wide distribution. Notwithstanding, most exports come from Lumbaulo and Malombe. It has been in the hobby for several decades now, being first imported in 1968. In the wild, C. moorii displays a very unique feeding adaptation. Classified as a micro-predator, it follows close behind substrate-digging cichlids - like Taeniolethrinops praeorbitalis, Fossorochromis rostratus, and Mylochromis lateristriga – and feeds on the small edible organisms and particles that get stirred up behind them as they feed.

In fact, as these fish dig in the sand looking for food, the resulting clouds attract C. moorii, like sharks to blood, but not as dramtatic. This is its only documented method of hunting for food in the lake.

C. moorii attain very respectable sizes. Males grow up to 8 inches (20cm) in length, and females up to 6.5 inches (16.5cm). While they certainly do grow larger than this, these are more typical lengths. The only downside to keeping this fish is that it takes a very long time to grow and reach sexual maturity. Typically, it will take about one and a half to two years for fry to reach 4-5 inches, at which point they will begin spawning. Juveniles are silver and begin taking on blue coloring at around 4cm. Interestingly, fry have an orangish-yellow anal fin, which disappears a few months after hatching.

Despite requiring patience while waiting for these fish to grow and spawn for the first time, once they do reach sexual maturity all your patience will be rewarded. They turn into little clocks, spawning every two months, with clutches ranging between 20 and 90! Several days before spawning occurs, the male will begin to display more often to the female. He also becomes much more active, digging a nest out of the substrate or clearing off a smooth stone. The female will then lay her eggs either in the nest or on the stone and picks them up immediately.

Fertilization occurs before the female actually picks the eggs up in her mouth. The eggs hatch after 18 to 21 days and are usually released a week after that.

When attempting to catch a holding female, be very careful to not make any sudden moves that may frighten her. C. moorii females are notorious for spitting eggs when chased by a net. It is best to catch her at night, several hours after the lights have been out. If she does spit the eggs out during transport (i.e., in the net), drop the eggs in the new tank with the mother, as she will pick them up after an hour or so.

C. moorii are polygamous mouthbrooders and do best with one large male and several females. If you keep more than one (and preferably three to six), they will tend to cluster together and school around the tank. They tend to get along very well with just one lone male and several females. The two sexes are difficult to differentiate because there is no difference in coloration between them. Furthermore, there is no apparent correlation between hump size and gender. Having said that, there is quite a bit of variation in the shape and size of the fatty, fibrous hump on the forehead, which becomes larger with age.

Because of this fish’s giant proportions, adults and even sub-adults should not be kept in aquariums less than 125 gallons in size. This fish also needs a large open area to move around. Sand or a fine gravel such as aragonite are the best choices of substrate for this fish that is found in muddy bays and sandy coastal areas. It is known as one of the chisawasawa, or sandy bottom-associated cichlids. It is a sifter, and eats the smaller bits of food left behind after feeding time. Rocks are okay, but should be kept to the back or corners of the tank. This is important because C. moorii gets startled easy and could potentially get injured if the tank is cramped with rocks. Also, note that it will burrow down into the substrate, but won’t harm any live plants

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