Lake Malawi

July 8th, 2007
by andyux

This is fresh water!

lake_malawi.jpg

lake-malawi.jpg

LAKE MALAWI

Lake Malawi, known locally as Lake Nyasa, is the ninth largest lake in the world and lies between the countries of Malawi on the west and Tanzania and Mozambique on the east. It is 360 miles long and 25 miles wide, with an approximate area of 8,683 sq mi, and reaches depths of 2,300 feet. The lake has a visibility of up to 70 feet.

Lake Malawi contains a greater variety of indigenous species of Cichlid fishes than any other lake in the world. World Wildlife Fund researchers have identified over 500 species to date that are not found anywhere else in the world. That is more than all of the freshwater species found in all the waters of both Europe and North America. The Cichlids of Lake Malawi, perhaps even more so than the Cichlids from the other two rift lakes, are brightly colored and patterned. For this reason, they have been a big hit with aquarists all over the world.

Among these popular Cichlids are the Mbuna and the Haps.

The “Mbuna” (i.e., rock-dwelling fish) are a large group of Cichlids that live among large piles of rocks along the shoreline. They are usually seen in large groups, but are by no means a schooling fish. In some areas of Lake Malawi, 20 fish per square meter is not uncommon. Both sexes of the more than 100 species of Mbuna are unusually colorful, whereas typically, only males have color. They are very colorful with bright patterns of horizontal stripes or vertical bars. Mbuna are smaller and tend to have flat faces, which enables them to better scrape algae from rocks. These consist mostly of, but not limited to, the genera Pseudotropheus, Labidochromis, Mealnochromis, Labeotropheus and Metriaclima.

Haps, for want of a better name, are basically a non-Mbuna flock that are informally called “Haps” because many of these fish once belonged to the broad genus Haplochromis Hilgendorf.

Most Haps are piscivores, unlike the vegetarian Mbuna. There are some exceptions to this generalization, however, but these do well on a piscovore’s diet nonetheless. Haps are aggressive, but not as aggressive as the vegetarian Mbuna. They have long, slender, almost torpedo-like bodies, and cruise the open water. Most of these fish are silver or gray when small, and the males become very brightly colored as they mature. Females typically remain without color. For more information on Haps and Mbuna, see Haps Vs. Mbuna.

The water chemistry in Lake Malawi is very similar to that of Lake Victoria. For this reason, many species from these two lakes can be housed together. Lake Malawi’s pH ranges from 7.8 to 8.6, with a total hardness of 4.0-6.0 dH. The reason for the variation is caused by the level of Carbon Dioxide dissolved in the water. In areas with turbulent water, where the water is better aerated, the pH is higher, while in calm bays, the level of dissolved Carbon Dioxide is higher; consequently, the pH is lower there. Surface temperature ranges from 76 to 85 degrees, while the temperature at lower levels of the lake remain at a constant 70 degrees. Carbonate hardness ranges from 6.0 to 8.0.

About one third of the coast is rocky, which is home to the mbunas. The remaining shoreline is characterized by sandy beaches and bottoms. This is where most of the open-water Haps and peacocks dwell. A few Cichlid species inhabit the muddy and weed-strewn bottom where larger rivers flow into the lake. The shores of the lake are generally sandy, and the resort areas are generally bilharzias free. Lake Malawi is unusual in that it does not have tides or currents.

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