We can model a dusty plasma as a multispecies plasma, neglectin g density and momentum losses and gain s for the plasma electrons and ions, provided the dust chargin g is slow and hence the grain charges can be treated as constant. It is well known that nonlin ear waves in multispecies plasmas give rise to soliton structures. For electromagnetic waves propagatin g parallel to an ambient magnetic field a derivative nonlin ear Schrödin ger equation is obtain ed, while for perpendicular and oblique electrostatic and electromagnetic modes the situation is adequately described by a Korteweg-deVries equation. The localized solutions of these equations are used to analyze the width and height of the structures for a monosized dusty plasma. In reality however, different dust sizes coexist, and this affects the modes on the lin ear level. The in fluence on the nonlin ear description is examin ed, and possible astrophysical applications as planetary rin gs, cometary environments and a dusty in terstellar medium are discussed.