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.
Class Osteichthyes (the bony fish) is the largest class of vertebrates with over 20,000 species. The total numbers of fishes exceed that of all other kinds of vertebrates combined.obe-finned fish, the other type of bony fish, have muscular fins supported by bones. Only one species of lobe-finned fish, the coelacanth, still lives. Key features of Osteichthyes. 1  Skeleton more or less bony, vertebrae numerous. 2  Skin with mucous glands and embedded dermal scales. 3  some without scales. 4  Paired fins.