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.
Key features of Chondrichthyes. 1  Resemble bony fish and terrestrial vertebrates in having jaws, paired appendages, visceral arches located deeply next to the pharynx, an inner ear with three semicircular canals, and paired nasal cavities.2  An electroreceptive system is well developed.3  Skin with placoid scales and mucous glands; teeth of modified ... Resemble bony fish and terrestrial vertebrates in having jaws, paired appendages, visceral arches located deeply next to the pharynx, an inner ear with three semicircular canals, and paired nasal cavities. 2  An electroreceptive system is well developed.