A comparative study of the free amino acids in the haemolymph of a millipede, Spirostreptus asthenes, and a centipede Ethmostigmus spinosus (Myriapoda)

• 1.

  1. Free amino acids of the haemolymph of a millipede Spirostreptus asthenes and a centipede Ethmostigmus spinosus were determined by the methods of Folin and Spackman et al.

• 2.

  2. Seventeen amino acids (alanine, arginine, aspartic acid, cystine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenyl alanine, proline, serine, threonine, tyrosine and valine) were present in high concentrations.

• 3.

  3. The presence of cystine is suggested to be characteristic of myriapods.

• 4.

  4. Total concentrations of free amino acids were comparable to those of the primitive hemimetabolus insects.