Alcolapia grahami, the Lake Magadi tilapia or Graham's cichlid, is a vulnerable species of fish in the family Cichlidae. It is specialised to live in hot, alkaline waters in springs and lagoons around hypersaline lakes.
Alcolapia grahami is sexually dimorphic, the mature females are golden in colour while the males have pale blue flanks. In the mature males the sides of the mouth have swollen, brilliant white patches and blue iridescent spots on their scales. The males' genital papillae are obvious, conical in shape and bright yellow, those of the females are swollen. The breeding male has a very dark, black bar through its eyes and this is duller in females.[2]
It is endemic to the hypersaline, warm and highly alkaline Lake Magadi in Kenya where it is the only fish. It has also been introduced to Lake Elmenteita and Lake Nakuru in Kenya, and Lake Natron in Tanzania, although it does not appear to have become established in Natron.[2]
Alcolapia grahami is found in the springs and lagoons around the margin of the lake. Its habitat is one which is normally unfavourable to fishes due to environmental conditions such as water temperature and chemical composition.[1] They are active feeders in the evenings[2] and their main food sources are blue green algae, copepods and the larvae of Diptera,[1] the invertebrates being taken from the surface.[2] The young of this species consume the eggs as the female lays them which means that the territorial male spends much of his time and energy trying to drive these young fish out of the breeding site.[1]
They form pairs which last for a single breeding cycle.[1] The male excavates a pit in the substrate for breeding, the structure of the pit is variable depending on the type of substrate. Breeding behaviour is more frequent and active in the mornings. The female sheds around 3-10 eggs at each breeding event, and immediately gathers them into her mouth then the male swims so that his genital papilla are near to the female's the mouth, likely emitting milt. The female broods the eggs and fry for a reported period of 12–16 days.[2]
The fish is obligately ureotelic (urea excreting), unlike most teleosts which produce ammonia. The reason for this appears to be due to the difficulty of diffusing ammonia into a highly alkaline environment, not pH regulation as previously thought. Efficient nitrogen excretion is particularly crucial as the fish feeds on cyanobacteria which have a very high nitrogen content. Urea is also used in a small way, but significantly, in osmoregulation. Due to the salinity of the lake, A. grahami has an unusually high osmolarity of around 580 mosm, about half that of seawater. For comparison, most marine teleosts have an osmolarity of only around a third of seawater. Sodium chloride is the main contributor to this osmolarity, though around three times as much sodium than chloride ions are present.[3]
A. grahami has been shown to be able to tolerate temperatures of 42 °C and has been observed in 38 °C water naturally. At high temperatures, the solubility of oxygen in water decreases. Owing to a very high rate of urea production, and the elevated metabolic rate this causes, this is a particularly significant problem for the fish. During such times, they have been observed to gulp air to increase their oxygen intake.[4]
Although A. grahami lives in a very hostile environment, at least one species of parasite has managed to resist the same conditions, the Monogenea Gyrodactylus magadiensis Dos Santos, Ndegwa Maina & Avenant-Oldewage, 2019.[5] This parasite lives on the gills of the fish and thus is in direct contact with the water of the lake.
The generic name is a compound of alco referring to the alkaline habitat of the fishes in this genus and lapia, as the genus was originally named as a subgenus of Tilapia. The specific name honours the person who collected the type, J.W. Graham, but in his description Boulenger gives no other information about Mr Graham.[6]
Alcolapia grahami Alcolapia grahami, the Lake Magadi tilapia or Graham's cichlid, is a vulnerable species of fish in the family Cichlidae. It is specialised to live in hot, alkaline waters in springs and lagoons around hypersaline lakes.
Alcolapia grahami Alcolapia generoko animalia da. Arrainen barruko Actinopterygii klasean sailkatzen da, Cichlidae familian.
Alcolapia grahami Alcolapia generoko animalia da. Arrainen barruko Actinopterygii klasean sailkatzen da, Cichlidae familian.
Alcolapia grahami est une espèce de poisson qui fait partie de la famille des Cichlidae et de l'ordre des Perciformes.
Alcolapia grahami est une espèce de cichlidae endémique de l'Afrique. Elle se rencontre dans les lacs Magadi, Nakuru, où elle a été introduite (Kenya), et Natron en Tanzanie[1].
Cette espèce de cichlidae vit dans une eau dure et salée, se rapprochant de celle des poissons d'eau de mer. Les lacs salins de cette zone africaine sont également très chauds.
Alcolapia grahami est une espèce de poisson qui fait partie de la famille des Cichlidae et de l'ordre des Perciformes.
Alcolapia grahami is een straalvinnige vissensoort uit de familie van de cichliden (Cichlidae).[1] De wetenschappelijke naam van de soort is voor het eerst geldig gepubliceerd in 1912 door Boulenger.
Bronnen, noten en/of referenties
Alcolapia grahami é uma espécie de peixe da família Cichlidae.
Pode ser encontrada nos seguintes países: Quénia e Tanzânia.
Os seus habitats naturais são: lagos salinos intermitentes.
Alcolapia grahami é uma espécie de peixe da família Cichlidae.
Pode ser encontrada nos seguintes países: Quénia e Tanzânia.
Alcolapia grahami là một loài cá thuộc họ Cichlidae. Nó được tìm thấy ở Kenya và Tanzania. Môi trường sống tự nhiên của chúng là hồ nước mặn có nước theo mùa.
Bài viết chủ đề bộ Cá vược này vẫn còn sơ khai. Bạn có thể giúp Wikipedia bằng cách mở rộng nội dung để bài được hoàn chỉnh hơn. Alcolapia grahami là một loài cá thuộc họ Cichlidae. Nó được tìm thấy ở Kenya và Tanzania. Môi trường sống tự nhiên của chúng là hồ nước mặn có nước theo mùa.
格氏雀麗魚，為輻鰭魚綱鱸形目隆頭魚亞目慈鯛科的其中一種，被IUCN列為易危保育類動物，分布於非洲坦尚尼亞及肯亞Magadi及Nakuru湖流域，體長可達20公分，棲息在中底層水域，主要在夜晚活動，雄魚具有領域性，以無脊椎動物為食，可作為觀賞魚。
这是一篇關於魚類的小作品。你可以通过编辑或修订扩充其内容。 
