Fish are vertebrate animals, that is, they all have a vertebral column or âspineâ. There are two main groups of fish, bony fish (Teleosts) and cartilaginous fish (Elasmobranchs). As the common names imply, the skeletons of teleosts are made of bone while the elasmobranchs have cartilaginous skeletons.
1 The science of atomic radiation, atomic change and nuclear fission was developed from 1895 to 1945, much of it in the last six of those years.  Over 1939-45, most development was focused on the atomic bomb.
Dr. Glenn Seaborg and Edwin McMillan, Joseph Kennedy, and Arthur Wahl are credited with the discovery of plutionium. Plutonium was chemically identified in February in 1941 by Glenn T. Seaborg, Edwin M. McMillan, Joseph W. Kennedy, and Arthur C. Wahl at the Berkeley Laboratory of the University of California (United States). They synthesized and isolated it in December of 1940 after bombarding uranium with deuterons.