Crab in action on a sea urchin. Crabs are in the subphylum Crustacea. They are decapods (having ten legs), along with lobsters, crayfish and shrimps. Crabs form an order within the decapods, called the Brachyura. Their short body is covered by a thick exoskeleton.
Plummer's Disease is a condition where there is a single hyperfunctioning nodule producing excess thyroid hormone.Henry Plummer in 1913 described a clinically distinct form of thyrotoxicosis due to solitary or multiple toxic nodules in the thyroid.I restrict the term to a solitary a toxic nodule. This nodule is an adenoma (a benign tumour).enry Plummer in 1913 described a clinically distinct form of thyrotoxicosis due to solitary or multiple toxic nodules in the thyroid. I restrict the term to a solitary a toxic nodule. This nodule is an adenoma (a benign tumour).
Sirenomelia. Sirenomelia, alternatively known as Mermaid Syndrome, is a very rare congenital deformity in which the legs are fused together, giving them the appearance of a mermaid 's tail.ore than half the cases of sirenomelia result in stillbirth and this condition is 100 times more likely to occur in identical twins than in single births or fraternal twins.