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.
Those are the major characteristics of vertebrates. Invertebrates. Invertebrates are simply the animals without a backbone. Invertebrates are a large group of animals that consist of more than 97% of all the animal species with a broad collection of animals including many Phylas and Subphylas. Vertebrates have a backbone with a spinal cord, whereas invertebrates do not. â¢ The diversity is exceptionally high among the invertebrates compared to vertebrates. â¢ Vertebrates are always bilaterally symmetrical, while invertebrates could show either bilateral or radial symmetry.