Tanganyika bump head
|Tanganyika bump head|
Tanganyika bump head ( Cyphotilapia frontosa )
|( Boulenger , 1906)|
The Tanganyika bump head ( Cyphotilapia frontosa ) is a large cichlid that lives endemically in the northern part of Central African Lake Tanganyika above rocky bottom. The animals are up to 35 centimeters long and prefer depths of 20 to 50 meters.
The Tanganyika bulge head is high-backed, laterally flattened and shows with light, whitish, gray-white, cream-colored or pale-blue basic color on the body sides six or seven blackish to deep blue stripes, of which the first runs through the eye and the last lies on the tail stalk. The fins are bluish to gray. Older specimens have a strongly pronounced forehead hump. Cyphotilapia frontosa has a less tall body than its sister species Cyphotilapia gibberosa (38.2 to 46.5% of the SL vs. 43.3 to 51.2% of C. gibberosa ). As a result, there are two rows of scales in the middle of the body between the upper and lower side lines . In C. gibberosa there are three. In a middle longitudinal row on the side of the body, C. frontosa has 33 to 35 scales, in C. gibberosa it is 34 to 36. The dorsal fin base and pectoral fins are shorter in C. frontosa (53.8 to 60.9% of the SL vs. 57.1 of the 64.6% of the SL and 31.3 to 41.7% of the SL vs. 36.0 to 47.2% of the SL). In the outer row of teeth of the upper jaw, C. frontosa has 39 to 62 teeth, in C. gibberosa there are 31 to 52. The teeth of the inner rows of teeth are conical, sometimes three-pointed, the outer ones conical or two-pointed. The number of gill rakes is 10 to 12. The pharyngeal teeth are very small, laterally flattened and more or less two-pointed.
- Fins formula : dorsal XVII – XIX, 8–10, anal III 7–8.
- Dandruff formula : mLR 34–36, SL 23–25 / 15–16.
Way of life
The Tanganyika bump head lives in more or less large groups mostly at depths of 30 to 40 meters, older animals also deeper. The fish feed mainly on molluscs and smaller fish. They are mouthbrooders that usually spawn in caves. The females look after the young fish up to an age of 6 weeks. A clutch can contain a maximum of 50 eggs, but there are rarely more than 20 to 25 eggs. They are almost the size of a pea.
The cichlid species Plecodus straeleni , a scale eater, mimics the Tanganyika bump head in its external appearance ( mimicry ) and can hardly be distinguished from it in the wild. For example, Plecodus straeleni can invade a group of Tanganyika bump heads unnoticed and, in a sudden attack, tear some scales from the sides of a Tanganyika bump head.
The Tanganyika bump head was first described in 1906 by the Belgian-British zoologist George Albert Boulenger as Paratilapia frontosa . In 1920 the British ichthyologist Charles Tate Regan introduced the genus Cyphotilapia for the species . In 2003, with Cyphotilapia gibberosa, a second Cyphotilapia species was described after Japanese scientists discovered that the Cyphotilapia population in the southern half of the lake differs significantly from the Tanganyika bump head ( Cyphotilapia frontosa ), which is thus restricted to the northern half of the lake . The two species probably separated from each other in the course of an allopatric speciation .
- Pierre Brichard: The Big Book of Tanganyika Cichlids. With all the other fish on Lake Tanganyika. Bede Verlag GmbH. 1995, ISBN 978-3927997943
- Günther Sterba : Freshwater fish of the world , Weltbild Verlag, Augsburg 1998, ISBN 3-89350-991-7
- Sterba, page 752.
- Tetsumi Takahashi and Kazuhiro Nakaya, 2003. New species of Cyphotilapia (Perciformes: Cichlidae) from Lake Tanganyika, Africa. Copeia 2003 (4): 824-832. doi: 10.1643 / IA03-148.1
- Brichard, page 294.
- Sterba, page 751.
- Brichard, page 295th
- Brichard, page 290th