Cichlids
Cichlid is a large group of fish that is found in Africa
with 1000 species, Central and South America with 300 species, India with 3 species and North America with 1
species. The member of this group have enormous variety of color patterns, habitats
and body forms. Ichthyologists have described a wide variety of feeding habits
in cichlids. These fish include algae scrapers, like Eretmodus, that nip food
with chisel-like teeth; insect pickers, like Tanganicodus; and snail eaters
All cichlids have two pairs of jaws. The mouth jaws are used
for scraping or nipping food and throat jaws are used for crushing or
macerating food before it is swallowed. Many cichlid mouth brood their young. A
female takes egg into her mouth after the eggs are spawned. She then inhales
sperms released by male, and fertilization and development takes place within
the female’s mouth! Even after the eggs hatch, younger are taken into the mouth
of female if danger threatens. Hundreds of variations in color patterns, body
form and behavior in this family of fishes illustrate the remarkable divers
present in one relatively small branch of the animal kingdom.
Feeding habit of Cichlid
The cichlid scale eaters of Africa feed on the scales of
other cichlids. They come close to a prey from behind and bite a mouthful of
scales from the body. The scales are then stacked and crushed by the second set
of jaws and sent to the stomach and intestine for protein digestion.
Body forms of cichlids
Michio Hou of Kyoto University found that there were two body
forms within the species Perissodus micolepis. One form had a mouth that was
asymmetrically curved to the right and the other form had a mouth that was
asymmetrically curved to the left side. The asymmetry allowed right-jawed fish
to approach and bite scales from left side of their prey and similarly,
left-jawed fish to approach and bite scales from right side of their prey. Both
right and left jawed fish have been maintained in the population; otherwise the
prey will eventually become wary of being attacked by one side.
Color patterns in cichlids
The variety of color patterns arose as a result of the
isolation of populations among sheltering rock piles separated by expanses of
sandy bottom. Breeding is more likely to occur within their isolated populations
because fish that venture ever the sand are exposed to predators.
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Figure (a) dogtooth (Cynotilapia afra)
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| Figure (b) Frontosa (Cyphontilapia frontosa) | |
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Cichlids of Africa exist in an amazing variety of color patterns,habitats and body forms. (a) This dogtooth cichlid (Cynotilapia afra) is native to
Lake
Malawi in Africa.Female brood developing eggs in her mouth to protect from predators. (b) This frontosa (Cyphontilapia frontosa) is native to
Lake
Tanganyika in Africa.
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