Skin Cancer Signs and Symptoms | Pictures of Skin Cancer and Precancerous Lesions [SLIDESHOW]
Like many cancers, skin cancers — including melanoma, basal cell carcinoma, and squamous cell carcinoma — start as precancerous lesions. These precancerous lesions are changes in skin that are not cancer, but could become cancer over time. Learn to spot the early warning signs of skin cancer. It can be cured if it’s found and treated early.
Sharks and rays are basal fish with numerous primitive anatomical features similar to those of ancient fish, including skeletons composed of cartilage. Their bodies tend to be dorso-ventrally flattened, they usually have five pairs of gill slits and a large mouth set on the underside of the head. The dermis is covered with separate dermal placoid scales . They have a cloaca into which the urinary and genital passages open, but not a swim bladder . Cartilaginous fish produce a small number of large, yolky eggs. Some species are ovoviviparous and the young develop internally but others are oviparous and the larvae develop externally in egg cases.