Cornish jack
Giant Nilhecht ( Mormyrops anguilloides )
The Giant Nilhecht ( Mormyrops anguilloides ) is an African freshwater fish and the largest representative of mormyrids ( Mormyridae ). It is widely distributed in Africa. Its range extends from Senegal to the White Nile and the Congo Basin. In East Africa it occurs in Lake Tanganyika, in Lake Albert and Lake Malawi before, in southern Africa in the middle and lower Zambezi, Buzi and Pungwe.
Features
With a maximum length of 1.50 meters and a maximum weight of 15 kg the Giant Nilhecht is the largest representative of mormyrids. His body is elongated, the default length is 4.9 to 7.5 times the body height. The snout is rounded, not extended tubular and as wide as high. Its length is 5.7 to 6.5 % of the standard length and 21.3 to 23.7 % of head length. The head is flattened to a concave on the top and 1.6 times longer than its height. The length of the head is contained 3.4 to 5.1 times in standard length. The mouth is large and terminal, not thickened fleshy chin. The teeth, in each case in a row of teeth 16 and 28 in the upper jaw and the lower jaw 14 to 28 are indented. The eyes are small and are closer to the mouth angle as the gill opening. Its diameter is 30 to 50% of the interocular distance. The shorter dorsal fin begins on the 10th anal fin ray and reaches 60 to 67 % of anal fin length. It is closer to the caudal fin base than to snout. The tail fins stalk is relatively long (11% of standard length ) and surrounded in a series of 16 scales. The caudal fin is relatively small, their praise are rounded.
- Fins formula: Dorsal 21-33, 38-51 Anal.
- Dandruff formula: SL 64-68.
Since the giant Nilhecht has a very large distribution area, the body of the individual relations populations partly differ from each other. For mormyrids the species is relatively light colored, gray - ocher on the top with a dark head, dark gray - yellow fins and a whitish belly and under the heads. Show up on the flanks parallel to the lateral line dark horizontal stripes, which are formed by the dark centers of the individual scales.
Like all mormyrids is also Mormyrops anguilloides for electric communication and electrical orientation capable. Its electric signal is wavy and three-phase. The total duration of the electrical signal is one millisecond.
Way of life
Juveniles of the giant Nilhechts mainly colonize the riparian areas and feed on small invertebrates, especially insect larvae and small shrimp. Adult fish live in deeper water zones or higher under overhangs and floating floating ferns ( Salvinia sp.). They are fish hunter and prey on cichlids, barbs and Labeo species. The Giant Nilhecht may be eight years or older. It spawns during the rainy season. A female can carry over 25,000 eggs.