A UC Davis Evolution and Ecology team has discovered that cichlid fishes in Africa’s Lake Victoria have suffered a unique and unexpected effect of evolutionary adaptation: mass extinction.
What happened to cichlid fish in Lake Victoria?
Nile perch (Lates niloticus) were introduced to Lake Victoria in the 1950s to boost the fishing industry. Though the introduction of Nile perch resulted in an economic boom, it almost caused cichlids, a native fish, to go extinct.
What is the origin of the cichlids found in Lake Victoria?
Geological evidence suggests that the lake dried out completely about 14,700 years ago. On the basis of phylogenetic analyses of almost 300 DNA sequences of the mitochondrial control region of East African cichlids, we find that the Lake Victoria cichlid flock is derived from the geologically older Lake Kivu.
What is the main cause of the loss of cichlid diversity in Lake Victoria?
An example of biodiversity loss was the extinction of over 200 species of cichlids in Lake Victoria; this was caused by the introduction of the Nile Perch as well as increased agriculture and fishing.
What is special about cichlids?
Fun Facts. Cichlids are an extremely diverse family of fishes, most of which are found in rift lakes in Africa. There are more than 500 species in just three lakes: Victoria, Malawi, and Tanganyika. Most are specialized feeders, which allows many different types to live together without much competition.
What happened to the cichlids?
A UC Davis Evolution and Ecology team has discovered that cichlid fishes in Africa’s Lake Victoria have suffered a unique and unexpected effect of evolutionary adaptation: mass extinction.
What causes death of fish in Lake Victoria?
According to the Kenya Marine and Fisheries Research Institute, the fish in sections of Lake Victoria have been dying due to suffocation.
Why Lake Victoria is famous?
Lake Victoria is the world’s largest tropical lake and the largest lake in the African Great Lakes region. The lake supports the largest freshwater fishery in the world, producing 1 million tons of fish per year and employing 200,000 people in supporting the livelihoods of 4 million people.
How many cichlids are in Lake Victoria?
500
Lake Victoria harbors more than 500 endemic cichlid species [1, 2].
Where are cichlid usually found?
The cichlids comprise a large family of freshwater fishes that live in tropical and subtropical waters of Africa, Central and South America, as well as parts of Jordan, Iran, India and Sri Lanka. Most cichlid species are found in three large lakes in East Africa: Lake Malawi, Lake Victoria and Lake Tanganyika.
What is the main reason for species loss in Australia?
Over-population. The greatest threat to biodiversity is the size and rate of growth of human population.
Why should people be concerned with the extinction of cichlids in Lake Victoria?
The devastation of cichlids has led to drastic changes in Lake Victoria; even the perch’s future is in doubt. The disappearance of most algae-eating cichlids allowed algae to flourish unchecked; this further depleted the lakes oxygen levels through the process described above.
What is the main cause of fish extinction?
Overfishing is closely tied to bycatch—the capture of unwanted sea life while fishing for a different species. This, too, is a serious marine threat that causes the needless loss of billions of fish, along with hundreds of thousands of sea turtles and cetaceans.
How do cichlids get pregnant?
Mouth-brooding African cichlid mating occurs something like this: the male digs out a cave (nest) for the female and lures her in by doing this silly fin shaking dance (there’s also a disturbing “kissing” version). She lays her eggs in the nest and he fertilizes them.
Where did cichlids originate?
If the distribution of modern cichlids is attributable purely to Gondwanan break-up, then it necessarily follows that the common ancestor of all living cichlids originated no later than the final separation between Madagascar–India and South America–Africa–Arabia.
Do cichlids have brains?
Similarly, the hindbrains of the sand-dwelling cichlids analyzed here appear to have a relatively conserved brain bauplan at base, but with substantial elaboration in size and modulation among species.
Why are ecologists interested in studying the cichlids in Lake Victoria?
Lake Victoria’s cichlids are akin to Darwin’s finches in the Galápagos Islands: in both cases, the variations provided an isolated picture of how adaptation to different niches could lead to the rapid evolution of new species from a common ancestor.
What is the greatest threat to indigenous fish species in Lake Victoria?
The loss of biodiversity of fish in Lake Victoria is due mainly to habitat degradation and loss, eutrophication, predation and competition from introduced non-native fish species (Nile perch and Nile tilapia) and, in some cases, the unsustainable use of the lake from overfishing or the use of improper fishing gears.
How many cichlids are there?
The cichlid family is incredibly diverse and it is also one of the largest families of vertebrates – there are over 1,600 scientifically described species of cichlid, though it is estimated that that the actual number of cichlids in existence ranges between 2,000 and 3,000.
What fish is responsible for the most human deaths?
Although the great white shark, tiger sharks, and bull sharks have far more recorded attacks on humans, the oceanic whitetip is generally believed to have killed the most people.
What is the top predator in Lake Victoria?
The principal predatory fishes are Lates niloticus, Bagrus docmac, Clarias mossambicus, Schilbe mystus and some species of Haplochromis (sensu lato). Other predators in Lake Victoria include fish-eating birds, fish-eating snakes, crocodiles and otters.