Танганьика көлінің түс өзгергіш балықтары

Species of fish

Tropheus moorii (blunthead cichlid) is a species of cichlid endemic to Lake Tanganyika in Africa. Over 40 different color morphs of this species are dispersed throughout the lake, ranging from dark green to flame red and yellow. They mostly feed on filamentous algae on the rocky shallows they inhabit. T. moorii is a maternal mouthbrooder, so eggs are fertilized and young are carried in the mouth of the female while they hatch and develop.

Both male and female adults occupy individual feeding territories. Blunthead cichlids inhabiting territories at greater depth tend to have smaller adult body sizes and larger territories compared to those in shallows. Males have larger territories than females. A female leaves her territory to pair with a male and usually visits several territories multiple times before choosing a male. After the male and female form a pair bond, the female forages in his territory up to three weeks under his protection before spawning. A female's ovaries do not fully mature until she pairs with a male and feeds from his territory. After spawning, the female leaves the male's territory to occupy a small unclaimed area for the mouthbrooding period. In contrast to the frequent movement of females, a male usually remains in his territory for months even if he is never visited by females. Other cichlid species that exhibit similar social monogamy in mating, such as V. moorii, do not always show genetic monogamy due to parasitic spawning (males fertilizing eggs of a female paired to another male). Spawning occurs on a rock surface, with the female laying up to 20 eggs which are bright orange in color. Eggs are incubated for 30 to 35 days, and when the young emerge from their mother's mouth, they are advanced enough in their physical development to live like adults.

Buccal feeding refers to the feeding a mouthbrooding mother does to feed her young located in her buccal cavity. T. moorii females have unusually high parental investment in their offspring since they produce large eggs and buccally feed their young. Among cichlids, T. moorii has a very high egg to adult body size ratio. In the early stages of mouthbrooding, a female rarely feeds, but after the eggs hatch, she begins feeding to nourish them. The mother effectively starves herself during the mouthbrooding period, since all nourishment she takes in goes to feed the young. The yolk sacs of the eggs are depleted around the 25th day of mouthbrooding, but the offspring are not released for several more days, so in that time, all of their nourishment must come from buccal feeding. T. moorii individuals of a particular color morph are usually found in the same geographic area, so color morphs are also maintained by the relative isolation of T. moorii populations.

As a sexually monomorphic species, T. moorii can be quite challenging to sex. The upper lip of males is more prominent (i. e., larger) than that of females. Males' lips on average tend to be more off white, as well, due to their constant lip locking aggression. Furthermore, males tend to have a turned up nose, while females tend to have a greater slope and rounded nose, making the shape of their heads ellipsoid. Males generally grow at a faster rate and display their adult colors sooner. Males' coloration is also often more bold than females' because they display when courting females. Adult males also tend to have a deeper body, whereas females appear more slim and streamlined.

T. moorii is strictly herbivorous like all Tropheus species. They spend the majority of their time scraping algae from the rocks. In the wild, blunthead cichlids are found in shallow bays and in the upper reaches of the lake over rocky reefs where the water is quite illuminated, because this is where the algae and other vegetable matter grow most thickly. Consequently, they are adapted to bright light.

The specific name honours the discoverer of this species, John Edmund Sharrock Moore (1870 1947).