Freshwater butterflyfish

Butterfly fish ( Pantodon buchholzi )

The butterfly fish ( Pantodon buchholzi ) is a freshwater fish from rivers and streams of tropical West Africa.

Features

Pantodon buchholzi is ten to 15 inches long. He has a flattened on the dorsal side of the body, which is covered by large roundhouse. The mouth is large and upper constant, the nostrils tubular. In the lateral line series (SL ), one counts 26 to 30 scales, 21 to 26 are located in front of the far back, lying just before the tail fin dorsal fin. The short dorsal fin is supported by six, the long anal fin 9-15 fin rays. The posterior margin of the anal fin is nearly smooth edges in the females, on the other hand cut deep in the males. The middle rays form a tube to the inner fertilization. The caudal fin is large, long and frayed at the end. Your two middle fin rays are longest. The fin rays are striped light and dark in all the fins. The pectoral fins are enlarged wing-like. With them he can perform up to two meters wide Gleitsprünge. The pectoral fins do not flap it. The pelvic fins sit forward and have four filamentous very long fin rays, which are only connected to the body with fins membrane. The butterfly fish has 30 vertebrae and eight Branchiostegalstrahlen. In the gill cover the skeleton Suboperculare and sometimes the Interoperculare missing. With the help of the swim bladder of butterfly fish can breathe air. It is brownish in color.

Occurrence

The butterfly fish lives in disjunct distribution areas in rain forest areas in western Africa. The largest covers the northern and central part of the Congo Basin, another the river basins of the Niger, Benue and Ouémé and some other rivers of Benin to Cameroon. Isolated deposits are found in Lower Guinea and the Jong River in Sierra Leone.

Way of life

Pantodon buchholzi lives on the water surface in vegetation -rich swamps, jungle pools, streams and quiet sections of rivers. It feeds mainly on insects, eating next to small crustaceans and fish. Insects are taken mainly from the water surface when they have fallen into the waters, but can also be captured in shallow jump.

Reproduction takes place after a long courtship, when the male for hours on the back of the female "rides " and clings with its pelvic fins. The eggs are fertilized shortly before storage in the body of the female. Here, the animals rotate around each other. Each spawning 3-7 eggs are laid, a total of 80 to 220 The eggs float on the water surface, the young fish hatch at a water temperature of 25 ° C after three days.

System

Pantodon buchholzi in 1877 described by the German naturalist and zoologist Wilhelm Peters and assigned to a monotypic genus and family, which has been maintained to this day by most authors. Only the Canadian ichthyologist Joseph S. Nelson assigns Pantodon in the fourth edition of his standard work on fish systematics, Fishes of the World, the Knochenzünglern ( Osteoglossidae ) to. Wilson and colleagues see in Pantodon the sister group of a clade of osteoglossid with the Arapaimidae while Lavoue and employees Pantodon View as basal genus within the Knochenzünglerartigen that is in a sister group relationship with all recent Knochenzünglerartigen.

The following cladogram shows the hypotheses on the relationship of butterfly fish.

Butterfly fish ( Pantodon )

Butterfly fish ( Pantodon )

Arapaimidae

Osteoglossid ( Osteoglossidae )

Notopteroidei ( Old World knife fish, mormyrids and relatives )

The Mitochondrial DNA of the populations of the butterfly fish in the lower Niger basin and differ in the Congo Basin to 15.2% ( the whole genome of chimpanzees and humans differ in only about 1.37% ), which leads to the estimate that both populations of about 50 million years ago are genetically isolated from each other and could no longer mix. Morphologically, both populations but not at all differ. Thus buchholzi hide behind Pantodon possibly two or more cryptic species.

Attitude in the aquarium

Although Pantodon buchholzi is often offered in pet shops, it is, according to the guidelines of the Heidelberger decisions on animal welfare in Zoofachandel, only suitable for the aquarium trade. This is mainly due to its special characteristics and its feed requirements. In addition, the species is endangered because offspring are hardly yet succeeded and thus mainly go wild caught in the trade.