Fish live in schools. This life style is quite popular: out of 20 thousand fish species 4 thousand are organized in schools. For how long? It is known that cod schools stay together during their entire lives. For example, marked in May 1951, two cods were caught together in July 1953. The fish stayed together for over two years. (From “Zoology for Everyone: Fish”. Dolnik V., Kozlov M., 1997)
