SCANNING ELECTRON MICROSCOPE MORPHOLOGY AND AMINO-ACID ANALYSIS OF THE EGG-SHELL OF ENCYSTED BRINE SHRIMP, ARTEMIA SALINA LEACH (CRUSTACEA ANOSTRACA)

SUMMARY The fine structure of Artemia salina Leach (Crustacea Anostraca) egg-shell at the gastrula stage has been studied with the scanning electron microscope (SEM) and its amino-acids have been analyzed. SEM studies of the morphology of the egg-shell—the first reported for Crustacea—show it to consist of three well-defined layers: a compact inner fibrous layer or embryonic cuticle, a thick alveolar layer and an outer cortical layer. No specialized micropylar area, typical of the eggs of many invertebrate species, has ever been found. The amino-acid composition data reveal a rather uniform amino-acid content. There is no one predominant amino-acid residue: alanine, aspartic acid, serine and proline are the most abundant with similar relative values while sulphur-containing amino-acids (cystine and methionine) have been found only in small quantities. The amino acid composition of A. salina egg-shell has been compared with that of cirripede eggs and the relationships discussed.