X-ray Microanalysis of the Cuticle Surface of Two Southern California Marine Isopod Species

Abstract

Energy dispersive (EDS) x-ray microanalysis (XRMA) was used to <br /><br />determine the elemental composition of thoracic (pereonal) epicuticle in two <br /><br />isopod crustacean species, Colidotea rostrata and Excorallana tricornis occiden- <br /><br />tal. This represents the first study analyzing the cuticle of marine isopods using <br /><br />EDS techniques. The most common elements (with an atomic number greater <br /><br />than sodium) in both species were calcium, magnesium, potassium, silicon, phos- <br /><br />phorus, and aluminum, with calcium making up 86-95% of total elemental com- <br /><br />position in all analyses. There were significant interspecific differences in elemental <br /><br />composition. Other elements identified in these species include the heavy metals <br /><br />strontium, neobium, molybdenum, dyprosium, lanthanum, and platinum. These <br /><br />heavy metals have not been reported as normal constituents of isopod cuticle, <br /><br />and may be indicative of marine pollution in the coastal waters of southern <br /><br />California and northern Baja California.