Different Symptoms for Different Causes of Pain. Orchialgia caused by infection is severe and even in cutting pain accompanied by fever with chilliness, reddened and swollen scrotum, and apparent tenderness. Most bacterial orchitis is caused by adjacent epididymal inflammation, so it is also called epididymo-orchitis.
From Wikipedia, the free encyclopedia. Agnatha (Greek, no jaws) is a superclass of jawless fish in the phylum Chordata, subphylum Vertebrata, consisting of both present (cyclostomes) and extinct (conodonts and ostracoderms) species. The group excludes all vertebrates with jaws, known as gnathostomes.he Agnatha are ectothermic or cold blooded, with a cartilaginous skeleton, and the heart contains 2 chambers.
Five Basic Characteristics of Fish By Stuart Robertson; Updated April 24, 2017 Fish is an animal category that encompasses many species of water dwellers, and even a few species that do not spend all that much time in the water. There are several basic characteristics that are common to most fish, but only a few, like the presence of gills, can be applied to all fish. In fact fish are the most diverse animal species, among the vertebrates, with 32,000 members according to FishBase, a comprehensive database of information on fish used by researchers and zoologists.