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.
Vertebrate Traits and Diversity. Vertebrates have a central column of bones -- the vertebral column -- which houses much of the nervous system. Vertebrates are a very successful group of animals and they have diverged into numerous groups, including reptiles, fish, amphibians and mammals.ertebrates have a central column of bones -- the vertebral column -- which houses much of the nervous system. Vertebrates are a very successful group of animals and they have diverged into numerous groups, including reptiles, fish, amphibians and mammals.