Body piercing is frequently done in the form of a ladder. Modern body piercing practices also include dermal anchoring or dermal piercing, which combines piercing and implantation to create a single point of opening in the body (whereas pocketing creates two) to permit one end of the jewellery to show above the surface of the skin. While this technique can be performed almost anywhere on the body, as of 2007 it was popularly done between the eyes, on the chest, or on the finger, to simulate a ring. The practice of body piercing is subject to trends and fashions. Belly button and
Cephalopod dermal structures "Lepidoteuthis grimaldii" are actually dermal cushions with a vacuolate internal structure that are continuous with a similarly vacuolate underlying layer of mantle tissue. Ammonium ions (NH) are present in the mantle of this species at a measured concentration of 172 mM. Structurally very similar (though non-overlapping) dermal cushions are found in "Pholidoteuthis adami". It has been proposed that these two species achieve buoyancy by means of the fluid stored in their vacuolate dermal cushions and upper mantle layer. Given their spongy form, these cushions may also play a secondary protective role. The complex dermal structures of "Pholidoteuthis massyae" may play