The Illustrated Encyclopedia of Aquarium Fish [antikvár]

Chapter 1 CHILDREN OF THE SUN Neon Tetra [21 Waracheirodon innesi) stands out boldly in a shoal and on the dark bottom of a dimly lighted aquarium. Freshwaters of the tropical and subtropical regions of Africa and Central and South America are, as a rule, inhabited by large populations of colourful fish of the suborder Characinoidei which fully deserve their name 'children of the sun'. They live in all waters of the rain forests, from torrents to rivers, and in savanna regions with shallow waters which are exposed to the sun. These fish are mostly very thermophilic and are subject to only small fluctuations of temperature (ranging mostly within 1 to 2°C) during the day and throughout the year. The optimum temperature for keeping them in captivity is about 25°C. The majority of them are lively, sociable and gregarious. For this reason they have become popular with aquarists throughout the world as valuable members of aquarium fish communities. Of the wide variety of families belonging to this suborder, only the representatives of the best known will be mentioned. These include the Characidae, Hemiodontidae, the hatchetfish iGasteropelecidae), Alestidae, Lebiasi-nidae, Citharinidae, Serrasalmidae, and Characidiidae. A few characoids, such as some representatives of the family Serrasalmidae, are true predators; these include the vicious Black Piranha, orpiraya, which is among the most feared freshwater fish of South America. kang-finned Characin [3, 41 (.Brycinus longipinnis) The native waters of this fish are in tropical West Africa from Sierra Leone down to the river Congo. The males are larger than females and grow to 13 cm in length. Secondary sexual differences in the Long-finned Characin are pronounced and conspicuous. The male's body is markedly elongate; the dorsal fm rays are frayed, the abdominal fins thread-like and the anal fin is arched with a whitish edge. In the females each fm is much shorter and the anal fin margin is straight or slightly concave. <2 3